Hi all,
A quick update to my new project to improving the Arrow antenna, efficiency wise. I wanted to see how well it would perform on gaining and losing access during AOS and LOS. AO-27 is not a good choice since the timer is turned on when it is well above the AOS horizon and it is switched off before it reaches its LOS horizon. That leaves a dependable AO-51 to test it out.
With the last setup, the OEM diplexer provided by Arrow Antenna, I would copy AO-51 about 3 minutes after AOS and lose it about 3 to 4 minutes before LOS. Not bad, but people were saying they worked the birds when they were 1 degree off of the horizon. I have some pine trees that could be an issue but they are spaced far enough apart that I can work between them and I also have to deal with the McCollough Range to the SSE of me here in Las Vegas, NV. Today, there were 2 passes of AO-51, one at 12 degrees elevation, the other at 74 degrees. During both passes, I began to copy the downlink about a 1.25 minute after AOS. A considerable difference from 3 minutes. The downlink also improved down to about minute before LOS. On the last pass I worked KG6NUB at 0124z and LOS was 0125z and my downlink sounded fairly good, though I was fighting desense. (That's another issue I need to resolve.) Also, on both passes, I never once lost the downlink. No dropouts or fades. I'm still amazed.
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering if this was going to happen and it did. The reason that this happened was with the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general direction and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without dropouts or fades. Makes sense. What I've regained over the lossy diplexer makes up for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much this system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Jeff --
I really appreciate you doing this research for us. Two additional ideas come to mind:
1. Those of us with FT-817s could configure its two RF ports to use different bands and connect the rig directly to the beam's antenna connectors, bypassing the duplexer. For this purpose, higher-quality bnc terminated cable would be useful.
2. If I'm correct, your replacement duplexer is rather larger than the one it is replacing. It would be a great topic for a Journal article if someone with the necessary equipment and expertise were to design a replacement with less loss.
73, Bruce VE9QRP
On Fri, Sep 25, 2009 at 6:10 AM, Jeff Yanko wb3jfs@cox.net wrote:
Hi all,
A quick update to my new project to improving the Arrow antenna, efficiency wise. I wanted to see how well it would perform on gaining and losing access during AOS and LOS. AO-27 is not a good choice since the timer is turned on when it is well above the AOS horizon and it is switched off before it reaches its LOS horizon. That leaves a dependable AO-51 to test it out.
With the last setup, the OEM diplexer provided by Arrow Antenna, I would copy AO-51 about 3 minutes after AOS and lose it about 3 to 4 minutes before LOS. Not bad, but people were saying they worked the birds when they were 1 degree off of the horizon. I have some pine trees that could be an issue but they are spaced far enough apart that I can work between them and I also have to deal with the McCollough Range to the SSE of me here in Las Vegas, NV. Today, there were 2 passes of AO-51, one at 12 degrees elevation, the other at 74 degrees. During both passes, I began to copy the downlink about a 1.25 minute after AOS. A considerable difference from 3 minutes. The downlink also improved down to about minute before LOS. On the last pass I worked KG6NUB at 0124z and LOS was 0125z and my downlink sounded fairly good, though I was fighting desense. (That's another issue I need to resolve.) Also, on both passes, I never once lost the downlink. No dropouts or fades. I'm still amazed.
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering if this was going to happen and it did. The reason that this happened was with the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general direction and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without dropouts or fades. Makes sense. What I've regained over the lossy diplexer makes up for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much this system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
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On Sep 25, 2009, at 7:53 AM, Bruce Robertson wrote:
- If I'm correct, your replacement duplexer is rather larger than the
one it is replacing. It would be a great topic for a Journal article if someone with the necessary equipment and expertise were to design a replacement with less loss.
There is a diplexer that is easy to make and has good performance in this article:
< http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf >
As a bonus you get details on how to build your own handheld antenna for LEO Satellites. - Duffey
Yes, it is larger than the OEM supplied by Arrow, however, the loss is considerably less. I'll trade that any day! :) I connected it directly to the radio's input using a double male adaptor, male N connector to male PL-259. No coax between the radio and diplexer.
73,
Jeff WB3JFS
----- Original Message ----- From: "James Duffey" jamesduffey@comcast.net To: "Bruce Robertson" ve9qrp@gmail.com Cc: "James Duffey" jamesduffey@comcast.net; "Jeff Yanko" wb3jfs@cox.net; "AMSAT-BB" amsat-bb@amsat.org Sent: Friday, September 25, 2009 8:20 AM Subject: Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
On Sep 25, 2009, at 7:53 AM, Bruce Robertson wrote:
- If I'm correct, your replacement duplexer is rather larger than the
one it is replacing. It would be a great topic for a Journal article if someone with the necessary equipment and expertise were to design a replacement with less loss.
There is a diplexer that is easy to make and has good performance in this article:
< http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf >
As a bonus you get details on how to build your own handheld antenna for LEO Satellites. - Duffey
----- Original Message ----- From: "Bruce Robertson" ve9qrp@gmail.com To: "Jeff Yanko" wb3jfs@cox.net Cc: "AMSAT-BB" amsat-bb@amsat.org Sent: Friday, September 25, 2009 3:53 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Jeff --
<snip>
2. If I'm correct, your replacement duplexer is rather larger than the one it is replacing. It would be a great topic for a Journal article if someone with the necessary equipment and expertise were to design a replacement with less loss.
73, Bruce VE9QRP
Hi Bruce, VE9QRP
See QEX March/April 2002 page 47 "A Low-Loss VHF/UHF Diplexer" by Pavel Zanek OK1DNZ Loss = 0.15 dB at VHF and 0.40 dB at UHF Insulation VHF/UHF = 70 dB Max RF power at VHF or UHF or VHF/UHF = 100 watt CW at 25°
73" de
i8CVS Domenico
Has anyone played with Kent's idea of insulating the elements from the boom?
73, Joe kk0sd
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Bruce Robertson Sent: Friday, September 25, 2009 8:53 AM To: Jeff Yanko Cc: AMSAT-BB Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Jeff --
I really appreciate you doing this research for us. Two additional ideas come to mind:
1. Those of us with FT-817s could configure its two RF ports to use different bands and connect the rig directly to the beam's antenna connectors, bypassing the duplexer. For this purpose, higher-quality bnc terminated cable would be useful.
2. If I'm correct, your replacement duplexer is rather larger than the one it is replacing. It would be a great topic for a Journal article if someone with the necessary equipment and expertise were to design a replacement with less loss.
73, Bruce VE9QRP
On Fri, Sep 25, 2009 at 6:10 AM, Jeff Yanko wb3jfs@cox.net wrote:
Hi all,
A quick update to my new project to improving the Arrow antenna,
efficiency
wise. I wanted to see how well it would perform on gaining and losing access during AOS and LOS. AO-27 is not a good choice since the timer is turned on when it is well above the AOS horizon and it is switched off before it reaches its LOS horizon. That leaves a dependable AO-51 to test it out.
With the last setup, the OEM diplexer provided by Arrow Antenna, I would copy AO-51 about 3 minutes after AOS and lose it about 3 to 4 minutes
before
LOS. Not bad, but people were saying they worked the birds when they were
1
degree off of the horizon. I have some pine trees that could be an issue but they are spaced far enough apart that I can work between them and I
also
have to deal with the McCollough Range to the SSE of me here in Las Vegas, NV. Today, there were 2 passes of AO-51, one at 12 degrees elevation, the other at 74 degrees. During both passes, I began to copy the downlink
about
a 1.25 minute after AOS. A considerable difference from 3 minutes. The downlink also improved down to about minute before LOS. On the last pass
I
worked KG6NUB at 0124z and LOS was 0125z and my downlink sounded fairly good, though I was fighting desense. (That's another issue I need to resolve.) Also, on both passes, I never once lost the downlink. No dropouts or fades. I'm still amazed.
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering
if
this was going to happen and it did. The reason that this happened was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
as in the texts below, there is something else going on here.
That Diplexor can not be all that bad. two reasons.
How many db down is the front to side of that antenna?
and I can not imaging someone would sell a diplexor that has greater than 20 db of losses.
because of the statement that how criticalpolarity was with the original, and now the antenna has to be nearly 90 degrees cross polarized to make it drop out uhh
that close to 30 db,
at least 20,,
something else is going on here
Gary "Joe" Mayfield wrote:
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering
if
this was going to happen and it did. The reason that this happened was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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To All, The Diplexer also acts as a filter. All solid state transmitters have "White Noise" contributions. If you receive while transmitting the White Noise from the 2M side will desense the 70 cm receiver. The amount of noise typically 60 dB down from the carrier varies with the type of output filter used in the transmitter. Of course this does not apply when working the satellite simplex. A bad diplexer can also be the problem. Soldering is poor in some of these overseas units, also excessive power in a former life will cook the parts inside. A good test with 50 loads and a power meter will tell the condition of the diplexer.
Art, KC6UQH
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Joe Sent: Friday, September 25, 2009 6:43 PM To: Gary "Joe" Mayfield Cc: 'AMSAT-BB' Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
as in the texts below, there is something else going on here.
That Diplexor can not be all that bad. two reasons.
How many db down is the front to side of that antenna?
and I can not imaging someone would sell a diplexor that has greater than 20 db of losses.
because of the statement that how criticalpolarity was with the original, and now the antenna has to be nearly 90 degrees cross polarized to make it drop out uhh
that close to 30 db,
at least 20,,
something else is going on here
Gary "Joe" Mayfield wrote:
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering
if
this was going to happen and it did. The reason that this happened was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: 09/25/09
17:52:00
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I rarely use my Arrow and 2 dual band HTs, but, dragged them out this week because I'm scheduled to do a high school demo in 2 weeks and thought I better start practicing my technique again, update the KEPS in my Palm PocketSat+ and get the battery packs charged.
So this discussion in the last couple of days is very relevant to me and here's my 2 cents...
The only compliant I have about the Arrow is that it looses it's speckles and the plastic tips fad to white when used outdoor for long periods :-) Several years ago I ran it for a full year on the roof with a hygain TV rotator and fixed EL of about 30 degrees. The arrows are now plain aluminium.
First I view all anecdotal comparisons of before and after results with some caution. A diplexer change from the OEM to another cannot account for the improvement in one pass with fades to the next pass with no fades IHMO. It is so, please tell me the science behind this. If a defective diplexer was acting as an attenuator then I sure can see there would be an improvement in signal. In my location, 2 low passes with the same max elevation on the same satellite can be quite different depending on which part of the horizon is below the pass - open prairie vs the noise floor of city. Sometimes there are fades and sometimes there aren't any. Satellites tumble. Sometimes to your advantage and some times they work against you.
Now, as to the Arrow OEM diplexer; with the 2 HT's I don't use it except as a mode J filter, see
http://www.amsat.org/amsat-new/articles/Mode-J/ to reduce desense, and, a mini UHF preamp
http://www.hsmicrowave.com/html/amateur_lna.htm , and, anecdotally I can tell you that I can see the increase in bars on S-PO Meter and these old ears can hear the difference when the preamp is switched on and off.
For those of you who want to use an external diplexer such as a Comet, you can still use the OEM diplexer at the same time as a filter.
BTW yesterday I just practiced listening and heard a monstrous booming signal from ISS, got to hear 4 or 5 answers to questions during the Ottawa ARISS with the Arrow and a max 10 degrees pass, no preamp needed, LOS just under 5 degrees. Also AO-27 max 20 degrees over Eastern NOAM until it went digital - ever notice it goes digital just as it hits the 49th parallel? Is that an anti-Canadian thing?
73, Alan VE4YZ EN19kv AMSAT LM 2352 http://www.wincube.ca
Hi Alan,
Sorry for the long reply. Between other e-mails, work and the RTTY contest over the weekend, I've been trying to find time. Your e-mail has raised some questions I had to think about or gather additional information.
As for the Arrow loosing its speckles and plastic tips. My belief is though the antenna is basically designed to be used as a portable setup, a permanent setup can be configured using the same antenna. However, being outside in certain climates, aluminum can become rather oxidized and very quickly too. Here in the desert, I've yet to see this occur on a severe case, like I used to see back in PA. I've seen aluminum poles in place for 4 years and when the sun hits it, there is a huge shine. The tips of the antenna are probably not UV hardened. Again, it was probably designed with portability in mind and not a base station setup where it would remain outside 24/7.
The observations I've been making with the Comet diplexer and the Arrow diplexer have been made with multiple passes at different elevations, ranges, etc. Strictly comparing previous passes, at the same elevations, to current ones with taking into consideration how the downlink compares.
You made the statement that you "view all anecdotal comparisons of before and after results with some caution." Which should be true in all cases not matter what the subject is. However, when you also questioned about the improvement of fades during a pass due to a diplexer change then asked "It is so, please tell me the science behind this." I must say there isn't any science behind it because anecdotal evidence is obtained through reports or observations of unscientific observers. Again, this is basic gathering of observations based on changing one device, the diplexer.
As for AO-27 turning off near the 49th parallel, I don't believe there is any anti-Canadian sentiment for this. :) Think about it this way, what if you lived near the 49th parallel in the southern hemisphere? Talk about anti-sentiment. :) If I recall correctly, the timer is set to turn on around the pass of the 28th parallel and off 7 minutes later, which takes it to near the 49th parallel. I would like to see AO-27 opened for 8 to 9 minutes if it could be spared. I've had some really nice passes get cut to digital with so much more room to LOS. So I guess maybe we should ask if it is possible to extend the timer by 1 or 1.5 minutes, if the bird can spare it.
73,
Jeff WB3JFS
----- Original Message ----- From: "Alan VE4YZ" ve4yz@mts.net To: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 8:44 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
I rarely use my Arrow and 2 dual band HTs, but, dragged them out this week because I'm scheduled to do a high school demo in 2 weeks and thought I better start practicing my technique again, update the KEPS in my Palm PocketSat+ and get the battery packs charged.
So this discussion in the last couple of days is very relevant to me and here's my 2 cents...
The only compliant I have about the Arrow is that it looses it's speckles and the plastic tips fad to white when used outdoor for long periods :-) Several years ago I ran it for a full year on the roof with a hygain TV rotator and fixed EL of about 30 degrees. The arrows are now plain aluminium.
First I view all anecdotal comparisons of before and after results with some caution. A diplexer change from the OEM to another cannot account for the improvement in one pass with fades to the next pass with no fades IHMO. It is so, please tell me the science behind this. If a defective diplexer was acting as an attenuator then I sure can see there would be an improvement in signal. In my location, 2 low passes with the same max elevation on the same satellite can be quite different depending on which part of the horizon is below the pass - open prairie vs the noise floor of city. Sometimes there are fades and sometimes there aren't any. Satellites tumble. Sometimes to your advantage and some times they work against you.
Now, as to the Arrow OEM diplexer; with the 2 HT's I don't use it except as a mode J filter, see
http://www.amsat.org/amsat-new/articles/Mode-J/ to reduce desense, and, a mini UHF preamp
http://www.hsmicrowave.com/html/amateur_lna.htm , and, anecdotally I can tell you that I can see the increase in bars on S-PO Meter and these old ears can hear the difference when the preamp is switched on and off.
For those of you who want to use an external diplexer such as a Comet, you can still use the OEM diplexer at the same time as a filter.
BTW yesterday I just practiced listening and heard a monstrous booming signal from ISS, got to hear 4 or 5 answers to questions during the Ottawa ARISS with the Arrow and a max 10 degrees pass, no preamp needed, LOS just under 5 degrees. Also AO-27 max 20 degrees over Eastern NOAM until it went digital - ever notice it goes digital just as it hits the 49th parallel? Is that an anti-Canadian thing?
73, Alan VE4YZ EN19kv AMSAT LM 2352 http://www.wincube.ca
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Just noticed this on QRZ.COM from Bill K7MT who used to be a regular on the FM sats a few years ago with his antenna on his helmet on the ski slopes in MT...
---------------------------------------------------------------------------- ----
Howdy from Bill K7MT Helena, Mt.
I will be deploying back to McMurdo Station Antarctica Nov 15, 2009 - Feb 20, 2010. I will be active from KC4USV Sundays 0000 GMT on SSB. I have requests from Europe to come in early around 1800 GMT on Saturdays so they can work Antarctica and I will be there. I am taking a rigblaster for PSK-31 on 14.070 and CW on 14.043 if time permits. I am also taking an Arrow II antenna/Kenwood TH-7 to work the FM satellites to VK and ZL land. Finally, if I get it operational, APRS VHF to HF with a Kam Plus. VK6CO will help me HF 30 meters with their HF APRS parameters. You just might see me driving out on the Ross Ice Sea as K7MT-7 in Ivan the Terra Bus. Pictures and information on my home web page at:
Qsl is via K1IED Larry who has done a terrific job with the QSL cards from Exel sprea sheet I will be sending to him weekly from McMurdo.
See ya on HF in about 45 days from McMurdo Station Antarctica.
Cheers Bill Erhardt K7MT
i noted a packet from antarctica via ISS as well
---------------------------------------------------------- Andrew Rich Airways Technical Officer Grade 4 Surveillance - RADAR ADS-B Amateur Radio Callsign VK4TEC email: vk4tec@tech-software.net web: www.tech-software.net ----- Original Message ----- From: "Alan VE4YZ" ve4yz@mts.net To: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Sunday, September 27, 2009 8:33 AM Subject: [amsat-bb] FM sats from Antartica for VK and ZL landers
Just noticed this on QRZ.COM from Bill K7MT who used to be a regular on the FM sats a few years ago with his antenna on his helmet on the ski slopes in MT...
Howdy from Bill K7MT Helena, Mt.
I will be deploying back to McMurdo Station Antarctica Nov 15, 2009 - Feb 20, 2010. I will be active from KC4USV Sundays 0000 GMT on SSB. I have requests from Europe to come in early around 1800 GMT on Saturdays so they can work Antarctica and I will be there. I am taking a rigblaster for PSK-31 on 14.070 and CW on 14.043 if time permits. I am also taking an Arrow II antenna/Kenwood TH-7 to work the FM satellites to VK and ZL land. Finally, if I get it operational, APRS VHF to HF with a Kam Plus. VK6CO will help me HF 30 meters with their HF APRS parameters. You just might see me driving out on the Ross Ice Sea as K7MT-7 in Ivan the Terra Bus. Pictures and information on my home web page at:
Qsl is via K1IED Larry who has done a terrific job with the QSL cards from Exel sprea sheet I will be sending to him weekly from McMurdo.
See ya on HF in about 45 days from McMurdo Station Antarctica.
Cheers Bill Erhardt K7MT
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hi Joe and all,
I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :)
I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line.
If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing.
I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each.
73,
Jeff WB3JFS ----- Original Message ----- From: "Joe" nss@mwt.net To: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com Cc: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
as in the texts below, there is something else going on here.
That Diplexor can not be all that bad. two reasons.
How many db down is the front to side of that antenna?
and I can not imaging someone would sell a diplexor that has greater than 20 db of losses.
because of the statement that how criticalpolarity was with the original, and now the antenna has to be nearly 90 degrees cross polarized to make it drop out uhh
that close to 30 db,
at least 20,,
something else is going on here
Gary "Joe" Mayfield wrote:
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering
if
this was going to happen and it did. The reason that this happened was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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No, Cross polarization in the real world is 20 to 30 db loss.
In the theoretical world it's infinite,
http://www.amsat.org/amsat/archive/amsat-bb/200101/msg01220.html
Joe WB9SBD
Jeff Yanko wrote:
Hi Joe and all,
I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :)
I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line.
If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing.
I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each.
73,
Jeff WB3JFS ----- Original Message ----- From: "Joe" nss@mwt.net To: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com Cc: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
as in the texts below, there is something else going on here.
That Diplexor can not be all that bad. two reasons.
How many db down is the front to side of that antenna?
and I can not imaging someone would sell a diplexor that has greater than 20 db of losses.
because of the statement that how criticalpolarity was with the original, and now the antenna has to be nearly 90 degrees cross polarized to make it drop out uhh
that close to 30 db,
at least 20,,
something else is going on here
Gary "Joe" Mayfield wrote:
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering
if
this was going to happen and it did. The reason that this happened was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: 09/25/09 17:52:00
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Folks,
I think you are focusing only on transmitting loss and have overlooked the impact that loss has on noise figure. If your HT has a low NF (doubtful) adding 3-dB loss in Rx will raise the NF 3-dB higher. The actual loss of sensitivity could be more than that.
Filter's size determines efficiency and insertion loss. The tiny diplexer in the Arrow is a compromise between performance and size. I have a Comet 416B and even it has some loss about 47w out for 50w in. But that is not anywhere near 3-dB. I use mine to connect my dual-band vertical to my FT-847 which has separate connectors for 2m and 70cm. I used this antenna to contact the ISS a few years ago (worked well because the ISS never rises above 11-deg. elevation, here).
But I do not use if for SSB or other weak-signal use.
Ed - KL7UW
At 02:26 AM 9/26/2009, Jeff Yanko wrote:
Hi Joe and all,
I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :)
I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line.
If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing.
I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each.
73,
Jeff WB3JFS ----- Original Message ----- From: "Joe" nss@mwt.net To: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com Cc: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
as in the texts below, there is something else going on here.
That Diplexor can not be all that bad. two reasons.
How many db down is the front to side of that antenna?
and I can not imaging someone would sell a diplexor that has greater than 20 db of losses.
because of the statement that how criticalpolarity was with the original, and now the antenna has to be nearly 90 degrees cross polarized to make it drop out uhh
that close to 30 db,
at least 20,,
something else is going on here
Gary "Joe" Mayfield wrote:
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering
if
this was going to happen and it did. The reason that this happened was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: 09/25/09 17:52:00
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com 500-KHz/CW, 144-MHz EME, 1296-MHz EME DUBUS Magazine USA Rep dubususa@hotmail.com ======================================
Howdy Jeff,
Someone asked and here we go. A file attachment follows.
Actually the diplexer looks pretty good. Less than half a db of loss at VHF and around half a dB at UHF. I checked the calibration and that was within tenth of a dB over the entire range.
Any questions.
Charles AA1VS
On Sat, Sep 26, 2009 at 6:26 AM, Jeff Yanko wb3jfs@cox.net wrote:
Hi Joe and all,
I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :)
I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line.
If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing.
I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each.
73,
Jeff WB3JFS ----- Original Message ----- From: "Joe" nss@mwt.net To: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com Cc: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
as in the texts below, there is something else going on here.
That Diplexor can not be all that bad. two reasons.
How many db down is the front to side of that antenna?
and I can not imaging someone would sell a diplexor that has greater than 20 db of losses.
because of the statement that how criticalpolarity was with the original, and now the antenna has to be nearly 90 degrees cross polarized to make it drop out uhh
that close to 30 db,
at least 20,,
something else is going on here
Gary "Joe" Mayfield wrote:
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was
wondering
if
this was going to happen and it did. The reason that this happened was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90
degrees
before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer
makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the
author.
Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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Hi Charles and the group,
FB on the numbers. Interesting to say the least and thanks for taking the time to look further into this topic.
Questions? I have a few after looking at these numbers and performing more observations.
First, are you testing just the diplexer and not the diplexer and the antenna combined? This could result in an overall number and not just the diplexer alone. How could there be a large discrepency between preliminary reports, 2.65dB and .5dB now. Could be equipment calibration, human error, etc. from previously tested, or attempted testing of the device. I don't believe any improvements have been made to the Arrow diplexer, but who knows?
Second, I switched back to the Arrow diplexer and made another comparison with the Comet diplexer. Again, no comparison, the Comet outperformed. Why would this happen if the two are pretty close to one another in numbers. The Comet has .25db loss at VHF and .26 at UHF.
Third, with the Arrow diplexer I wouldn't begin to receive the birds until almost 3 minutes after AOS, with the Comet diplexer a minute to 1.5 minutes after AOS. Yes, watch calibrated to WWV and multiple times of acquiring the birds. I've tried both setups with the HT and D710 and they both show the same results respectively, Arrow diplexer vs. Comet diplexer. The antenna and coax remain the same, the difference, the diplexer. May not be test lab quality but something is proving itself. What is it?
Finally, is it just my Arrow diplexer? Doesn't appear to be shorted or any defects to it. Actually looks great and assembled very well. I've encountered others saying the same thing. However, a very noticable difference to the overall performance.
73,
Jeff WB3JFS
----- Original Message ----- From: Charles Suprin To: Jeff Yanko Cc: Joe ; Gary "Joe" Mayfield ; AMSAT-BB Sent: Thursday, October 01, 2009 1:09 PM Subject: Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Howdy Jeff,
Someone asked and here we go. A file attachment follows.
Actually the diplexer looks pretty good. Less than half a db of loss at VHF and around half a dB at UHF. I checked the calibration and that was within tenth of a dB over the entire range.
Any questions.
Charles AA1VS
On Sat, Sep 26, 2009 at 6:26 AM, Jeff Yanko wb3jfs@cox.net wrote:
Hi Joe and all,
I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :)
I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line.
If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing.
I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each.
73,
Jeff WB3JFS ----- Original Message -----
From: "Joe" nss@mwt.net To: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com Cc: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
> as in the texts below, there is something else going on here. > > That Diplexor can not be all that bad. two reasons. > > How many db down is the front to side of that antenna? > > and I can not imaging someone would sell a diplexor that has greater > than 20 db of losses. > > because of the statement that how criticalpolarity was with the > original, and now the antenna has to be nearly 90 degrees cross > polarized to make it drop out uhh > > that close to 30 db, > > at least 20,, > > something else is going on here > > Gary "Joe" Mayfield wrote: > >>> >>>Another issue I came across was how wide the beamwidth is of the Arrow >>>Antenna between the Arrow diplexer and the new diplexer. I was wondering >>> >>> >>if >> >> >>>this was going to happen and it did. The reason that this happened was >>> >>> >>with >> >> >>>the old diplexer, the signal attenuated so much that you had to be >>>pointed >>>right smack dab on the bird, a few degrees off and you lost the signal. >>>Now, with the new diplexer, you can point the beam in the general >>> >>> >>direction >> >> >>>and still copy the bird. In most cases I had to turn the beam 90 degrees >>>before I completely lost the downlink! Twisting the antenna to make >>>polarization changes makes absolutely no difference now. This also >>>attributes to the fact that now I'm copying the entire pass without >>> >>> >>dropouts >> >> >>>or fades. Makes sense. What I've regained over the lossy diplexer makes >>> >>> >>up >> >> >>>for any polarization differences, etc. for a better copiable signal. >>> >>>Next weekend I will have to try more passes and get a feel of how much >>> >>> >>this >> >> >>>system has changed. >>> >>> >>>73, >>> >>>Jeff WB3JFS >>>Las Vegas, NV >>>DM26 >>> >>> >>> >>> >>> >>> >>>_______________________________________________ >>>Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>>Not an AMSAT-NA member? Join now to support the amateur satellite >>>program! >>>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>> >>> >>> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >> >>------------------------------------------------------------------------ >> >> >>No virus found in this incoming message. >>Checked by AVG - www.avg.com >>Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: >>09/25/09 17:52:00 >> >> >> > _______________________________________________ > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >
_______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Jeff,
The test was conducted with an anritsu two port network analyzer. Model number can be obtained if required. Each curve was made feeding the common port on the BNC cable as shipped from factory with the one end feeding into the VNA and the other leg terminated with 50 ohms. (The termination impacted out of band response significantly but did not seem to alter inband performance. No documentation provided.) These were then switched. The measurements were made inside the half boom of the disassembled version and no parts diplexer parts were removed. My version also came installed at the factory and not after the fact.
These measurements were made on the two port VNA at work instead of the three port as getting the three port calibrated would have been more painful.
As for your observations, is it possible the Arrow unit needs to be in the boom to be used. Perhaps that is a capacitor in the system. Additionally there are some sharp bends in the coax which generally can happen once but not repeated removal and addition.
If I stumble upon a calibrated antenna range, updates may follow.
Happy to answer this and any more questions.
Charles AA1VS
Jeff Yanko wrote:
Hi Charles and the group,
FB on the numbers. Interesting to say the least and thanks for taking the time to look further into this topic.
Questions? I have a few after looking at these numbers and performing more observations.
First, are you testing just the diplexer and not the diplexer and the antenna combined? This could result in an overall number and not just the diplexer alone. How could there be a large discrepency between preliminary reports, 2.65dB and .5dB now. Could be equipment calibration, human error, etc. from previously tested, or attempted testing of the device. I don't believe any improvements have been made to the Arrow diplexer, but who knows?
Second, I switched back to the Arrow diplexer and made another comparison with the Comet diplexer. Again, no comparison, the Comet outperformed. Why would this happen if the two are pretty close to one another in numbers. The Comet has .25db loss at VHF and .26 at UHF.
Third, with the Arrow diplexer I wouldn't begin to receive the birds until almost 3 minutes after AOS, with the Comet diplexer a minute to 1.5 minutes after AOS. Yes, watch calibrated to WWV and multiple times of acquiring the birds. I've tried both setups with the HT and D710 and they both show the same results respectively, Arrow diplexer vs. Comet diplexer. The antenna and coax remain the same, the difference, the diplexer. May not be test lab quality but something is proving itself. What is it?
Finally, is it just my Arrow diplexer? Doesn't appear to be shorted or any defects to it. Actually looks great and assembled very well. I've encountered others saying the same thing. However, a very noticable difference to the overall performance.
73,
Jeff WB3JFS
----- Original Message ----- *From:* Charles Suprin <mailto:hamaa1vs@gmail.com> *To:* Jeff Yanko <mailto:wb3jfs@cox.net> *Cc:* Joe <mailto:nss@mwt.net> ; Gary "Joe" Mayfield <mailto:gary_mayfield@hotmail.com> ; AMSAT-BB <mailto:amsat-bb@amsat.org> *Sent:* Thursday, October 01, 2009 1:09 PM *Subject:* Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE Howdy Jeff, Someone asked and here we go. A file attachment follows. Actually the diplexer looks pretty good. Less than half a db of loss at VHF and around half a dB at UHF. I checked the calibration and that was within tenth of a dB over the entire range. Any questions. Charles AA1VS On Sat, Sep 26, 2009 at 6:26 AM, Jeff Yanko <wb3jfs@cox.net <mailto:wb3jfs@cox.net>> wrote: Hi Joe and all, I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :) I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line. If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing. I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain? What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each. 73, Jeff WB3JFS ----- Original Message ----- From: "Joe" <nss@mwt.net <mailto:nss@mwt.net>> To: "Gary "Joe" Mayfield" <gary_mayfield@hotmail.com <mailto:gary_mayfield@hotmail.com>> Cc: "'AMSAT-BB'" <amsat-bb@amsat.org <mailto:amsat-bb@amsat.org>> Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE > as in the texts below, there is something else going on here. > > That Diplexor can not be all that bad. two reasons. > > How many db down is the front to side of that antenna? > > and I can not imaging someone would sell a diplexor that has greater > than 20 db of losses. > > because of the statement that how criticalpolarity was with the > original, and now the antenna has to be nearly 90 degrees cross > polarized to make it drop out uhh > > that close to 30 db, > > at least 20,, > > something else is going on here > > Gary "Joe" Mayfield wrote: > >>> >>>Another issue I came across was how wide the beamwidth is of the Arrow >>>Antenna between the Arrow diplexer and the new diplexer. I was wondering >>> >>> >>if >> >> >>>this was going to happen and it did. The reason that this happened was >>> >>> >>with >> >> >>>the old diplexer, the signal attenuated so much that you had to be >>>pointed >>>right smack dab on the bird, a few degrees off and you lost the signal. >>>Now, with the new diplexer, you can point the beam in the general >>> >>> >>direction >> >> >>>and still copy the bird. In most cases I had to turn the beam 90 degrees >>>before I completely lost the downlink! Twisting the antenna to make >>>polarization changes makes absolutely no difference now. This also >>>attributes to the fact that now I'm copying the entire pass without >>> >>> >>dropouts >> >> >>>or fades. Makes sense. What I've regained over the lossy diplexer makes >>> >>> >>up >> >> >>>for any polarization differences, etc. for a better copiable signal. >>> >>>Next weekend I will have to try more passes and get a feel of how much >>> >>> >>this >> >> >>>system has changed. >>> >>> >>>73, >>> >>>Jeff WB3JFS >>>Las Vegas, NV >>>DM26 >>> >>> >>> >>> >>> >>> >>>_______________________________________________ >>>Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. >>>Not an AMSAT-NA member? Join now to support the amateur satellite >>>program! >>>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>> >>> >>> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >> >>------------------------------------------------------------------------ >> >> >>No virus found in this incoming message. >>Checked by AVG - www.avg.com <http://www.avg.com> >>Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: >>09/25/09 17:52:00 >> >> >> > _______________________________________________ > Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > _______________________________________________ Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Greetings Charles,
FB on the test setup. Appears that everything was properly configured, etc.
In doing the comparison with the diplexers I would insert the Arrow diplexer into the boom just like the assembled version from the factory. Everything was the same. Again, the only difference were the diplexers. When removing the diplexer from the boom, I would loosen the cap with a screwdriver and never try to pull the unit out by the two looped pieces of coax.
Needless to say, some very interesting information on this device since I brought the topic up a couple weeks ago. Definately need more input from others on what they are or have observed.
73,
Jeff WB3JFS
----- Original Message ----- From: "Charles Suprin" hamaa1vs@gmail.com To: "Jeff Yanko" wb3jfs@cox.net Cc: "Joe" nss@mwt.net; "Gary "Joe" Mayfield" gary_mayfield@hotmail.com; "AMSAT-BB" amsat-bb@amsat.org Sent: Thursday, October 01, 2009 6:27 PM Subject: Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Jeff,
The test was conducted with an anritsu two port network analyzer. Model number can be obtained if required. Each curve was made feeding the common port on the BNC cable as shipped from factory with the one end feeding into the VNA and the other leg terminated with 50 ohms. (The termination impacted out of band response significantly but did not seem to alter inband performance. No documentation provided.) These were then switched. The measurements were made inside the half boom of the disassembled version and no parts diplexer parts were removed. My version also came installed at the factory and not after the fact.
These measurements were made on the two port VNA at work instead of the three port as getting the three port calibrated would have been more painful.
As for your observations, is it possible the Arrow unit needs to be in the boom to be used. Perhaps that is a capacitor in the system. Additionally there are some sharp bends in the coax which generally can happen once but not repeated removal and addition.
If I stumble upon a calibrated antenna range, updates may follow.
Happy to answer this and any more questions.
Charles AA1VS
Jeff Yanko wrote:
Hi Charles and the group, FB on the numbers. Interesting to say the least and thanks for taking the time to look further into this topic. Questions? I have a few after looking at these numbers and performing more observations. First, are you testing just the diplexer and not the diplexer and the antenna combined? This could result in an overall number and not just the diplexer alone. How could there be a large discrepency between preliminary reports, 2.65dB and .5dB now. Could be equipment calibration, human error, etc. from previously tested, or attempted testing of the device. I don't believe any improvements have been made to the Arrow diplexer, but who knows? Second, I switched back to the Arrow diplexer and made another comparison with the Comet diplexer. Again, no comparison, the Comet outperformed. Why would this happen if the two are pretty close to one another in numbers. The Comet has .25db loss at VHF and .26 at UHF. Third, with the Arrow diplexer I wouldn't begin to receive the birds until almost 3 minutes after AOS, with the Comet diplexer a minute to 1.5 minutes after AOS. Yes, watch calibrated to WWV and multiple times of acquiring the birds. I've tried both setups with the HT and D710 and they both show the same results respectively, Arrow diplexer vs. Comet diplexer. The antenna and coax remain the same, the difference, the diplexer. May not be test lab quality but something is proving itself. What is it? Finally, is it just my Arrow diplexer? Doesn't appear to be shorted or any defects to it. Actually looks great and assembled very well. I've encountered others saying the same thing. However, a very noticable difference to the overall performance. 73, Jeff WB3JFS ----- Original Message ----- *From:* Charles Suprin mailto:hamaa1vs@gmail.com *To:* Jeff Yanko mailto:wb3jfs@cox.net *Cc:* Joe mailto:nss@mwt.net ; Gary "Joe" Mayfield mailto:gary_mayfield@hotmail.com ; AMSAT-BB mailto:amsat-bb@amsat.org *Sent:* Thursday, October 01, 2009 1:09 PM *Subject:* Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Howdy Jeff, Someone asked and here we go. A file attachment follows. Actually the diplexer looks pretty good. Less than half a db of loss at VHF and around half a dB at UHF. I checked the calibration and that was within tenth of a dB over the entire range. Any questions. Charles AA1VS On Sat, Sep 26, 2009 at 6:26 AM, Jeff Yanko <wb3jfs@cox.net <mailto:wb3jfs@cox.net>> wrote: Hi Joe and all, I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :) I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line. If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing. I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overallgain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each. 73, Jeff WB3JFS ----- Original Message ----- From: "Joe" <nss@mwt.net <mailto:nss@mwt.net>> To: "Gary "Joe" Mayfield" <gary_mayfield@hotmail.com <mailto:gary_mayfield@hotmail.com>> Cc: "'AMSAT-BB'" <amsat-bb@amsat.org <mailto:amsat-bb@amsat.org>> Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE > as in the texts below, there is something else going on here. > > That Diplexor can not be all that bad. two reasons. > > How many db down is the front to side of that antenna? > > and I can not imaging someone would sell a diplexor that has greater > than 20 db of losses. > > because of the statement that how criticalpolarity was with the > original, and now the antenna has to be nearly 90 degrees cross > polarized to make it drop out uhh > > that close to 30 db, > > at least 20,, > > something else is going on here > > Gary "Joe" Mayfield wrote: > >>> >>>Another issue I came across was how wide the beamwidth is of the Arrow >>>Antenna between the Arrow diplexer and the new diplexer. I was wondering >>> >>> >>if >> >> >>>this was going to happen and it did. The reason that this happened was >>> >>> >>with >> >> >>>the old diplexer, the signal attenuated so much that you had to be >>>pointed >>>right smack dab on the bird, a few degrees off and you lost the signal. >>>Now, with the new diplexer, you can point the beam in the general >>> >>> >>direction >> >> >>>and still copy the bird. In most cases I had to turn the beam 90 degrees >>>before I completely lost the downlink! Twisting the antenna to make >>>polarization changes makes absolutely no difference now. This also >>>attributes to the fact that now I'm copying the entire pass without >>> >>> >>dropouts >> >> >>>or fades. Makes sense. What I've regained over the lossy diplexer makes >>> >>> >>up >> >> >>>for any polarization differences, etc. for a better copiable signal. >>> >>>Next weekend I will have to try more passes and get a feel of how much >>> >>> >>this >> >> >>>system has changed. >>> >>> >>>73, >>> >>>Jeff WB3JFS >>>Las Vegas, NV >>>DM26 >>> >>> >>> >>> >>> >>> >>>_______________________________________________ >>>Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. >>>Not an AMSAT-NA member? Join now to support the amateur satellite >>>program! >>>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>> >>> >>> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >>
>> >> >>No virus found in this incoming message. >>Checked by AVG - www.avg.com <http://www.avg.com> >>Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: >>09/25/09 17:52:00 >> >> >> > _______________________________________________ > Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > _______________________________________________ Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
We are missing the easy answer. He had diplexer that was off spec. It happens.
73, Joe kk0sd
-----Original Message----- From: amsat-bb-bounces@AMSAT.Org [mailto:amsat-bb-bounces@AMSAT.Org] On Behalf Of Jeff Yanko Sent: Thursday, October 01, 2009 4:28 PM To: Charles Suprin Cc: Joe; AMSAT-BB; Gary "Joe" Mayfield Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Hi Charles and the group,
FB on the numbers. Interesting to say the least and thanks for taking the time to look further into this topic.
Questions? I have a few after looking at these numbers and performing more observations.
First, are you testing just the diplexer and not the diplexer and the antenna combined? This could result in an overall number and not just the diplexer alone. How could there be a large discrepency between preliminary reports, 2.65dB and .5dB now. Could be equipment calibration, human error, etc. from previously tested, or attempted testing of the device. I don't believe any improvements have been made to the Arrow diplexer, but who knows?
Second, I switched back to the Arrow diplexer and made another comparison with the Comet diplexer. Again, no comparison, the Comet outperformed. Why would this happen if the two are pretty close to one another in numbers. The Comet has .25db loss at VHF and .26 at UHF.
Third, with the Arrow diplexer I wouldn't begin to receive the birds until almost 3 minutes after AOS, with the Comet diplexer a minute to 1.5 minutes after AOS. Yes, watch calibrated to WWV and multiple times of acquiring the birds. I've tried both setups with the HT and D710 and they both show the same results respectively, Arrow diplexer vs. Comet diplexer. The antenna and coax remain the same, the difference, the diplexer. May not be test lab quality but something is proving itself. What is it?
Finally, is it just my Arrow diplexer? Doesn't appear to be shorted or any defects to it. Actually looks great and assembled very well. I've encountered others saying the same thing. However, a very noticable difference to the overall performance.
73,
Jeff WB3JFS
----- Original Message ----- From: Charles Suprin To: Jeff Yanko Cc: Joe ; Gary "Joe" Mayfield ; AMSAT-BB Sent: Thursday, October 01, 2009 1:09 PM Subject: Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Howdy Jeff,
Someone asked and here we go. A file attachment follows.
Actually the diplexer looks pretty good. Less than half a db of loss at VHF and around half a dB at UHF. I checked the calibration and that was within tenth of a dB over the entire range.
Any questions.
Charles AA1VS
On Sat, Sep 26, 2009 at 6:26 AM, Jeff Yanko wb3jfs@cox.net wrote:
Hi Joe and all,
I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :)
I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line.
If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing.
I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each.
73,
Jeff WB3JFS ----- Original Message -----
From: "Joe" nss@mwt.net To: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com Cc: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
> as in the texts below, there is something else going on here. > > That Diplexor can not be all that bad. two reasons. > > How many db down is the front to side of that antenna? > > and I can not imaging someone would sell a diplexor that has greater > than 20 db of losses. > > because of the statement that how criticalpolarity was with the > original, and now the antenna has to be nearly 90 degrees cross > polarized to make it drop out uhh > > that close to 30 db, > > at least 20,, > > something else is going on here > > Gary "Joe" Mayfield wrote: > >>> >>>Another issue I came across was how wide the beamwidth is of the Arrow >>>Antenna between the Arrow diplexer and the new diplexer. I was wondering >>> >>> >>if >> >> >>>this was going to happen and it did. The reason that this happened was >>> >>> >>with >> >> >>>the old diplexer, the signal attenuated so much that you had to be >>>pointed >>>right smack dab on the bird, a few degrees off and you lost the signal. >>>Now, with the new diplexer, you can point the beam in the general >>> >>> >>direction >> >> >>>and still copy the bird. In most cases I had to turn the beam 90 degrees >>>before I completely lost the downlink! Twisting the antenna to make >>>polarization changes makes absolutely no difference now. This also >>>attributes to the fact that now I'm copying the entire pass without >>> >>> >>dropouts >> >> >>>or fades. Makes sense. What I've regained over the lossy diplexer makes >>> >>> >>up >> >> >>>for any polarization differences, etc. for a better copiable signal. >>> >>>Next weekend I will have to try more passes and get a feel of how much >>> >>> >>this >> >> >>>system has changed. >>> >>> >>>73, >>> >>>Jeff WB3JFS >>>Las Vegas, NV >>>DM26 >>> >>> >>> >>> >>> >>> >>>_______________________________________________ >>>Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>>Not an AMSAT-NA member? Join now to support the amateur satellite >>>program! >>>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>> >>> >>> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >>_______________________________________________ >>Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>Not an AMSAT-NA member? Join now to support the amateur satellite program! >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> >>
>> >> >>No virus found in this incoming message. >>Checked by AVG - www.avg.com >>Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: >>09/25/09 17:52:00 >> >> >> > _______________________________________________ > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >
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Could very well be.
73,
Jeff WB3JFS
----- Original Message ----- From: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com To: "'Jeff Yanko'" wb3jfs@cox.net; "'Charles Suprin'" hamaa1vs@gmail.com Cc: "'Joe'" nss@mwt.net; "'AMSAT-BB'" amsat-bb@AMSAT.Org Sent: Friday, October 02, 2009 6:27 PM Subject: RE: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
We are missing the easy answer. He had diplexer that was off spec. It happens.
73, Joe kk0sd
-----Original Message----- From: amsat-bb-bounces@AMSAT.Org [mailto:amsat-bb-bounces@AMSAT.Org] On Behalf Of Jeff Yanko Sent: Thursday, October 01, 2009 4:28 PM To: Charles Suprin Cc: Joe; AMSAT-BB; Gary "Joe" Mayfield Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Hi Charles and the group,
FB on the numbers. Interesting to say the least and thanks for taking the time to look further into this topic.
Questions? I have a few after looking at these numbers and performing more observations.
First, are you testing just the diplexer and not the diplexer and the antenna combined? This could result in an overall number and not just the diplexer alone. How could there be a large discrepency between preliminary reports, 2.65dB and .5dB now. Could be equipment calibration, human error, etc. from previously tested, or attempted testing of the device. I don't believe any improvements have been made to the Arrow diplexer, but who knows?
Second, I switched back to the Arrow diplexer and made another comparison with the Comet diplexer. Again, no comparison, the Comet outperformed. Why would this happen if the two are pretty close to one another in numbers. The Comet has .25db loss at VHF and .26 at UHF.
Third, with the Arrow diplexer I wouldn't begin to receive the birds until almost 3 minutes after AOS, with the Comet diplexer a minute to 1.5 minutes after AOS. Yes, watch calibrated to WWV and multiple times of acquiring the birds. I've tried both setups with the HT and D710 and they both show the same results respectively, Arrow diplexer vs. Comet diplexer. The antenna and coax remain the same, the difference, the diplexer. May not be test lab quality but something is proving itself. What is it?
Finally, is it just my Arrow diplexer? Doesn't appear to be shorted or any defects to it. Actually looks great and assembled very well. I've encountered others saying the same thing. However, a very noticable difference to the overall performance.
73,
Jeff WB3JFS
----- Original Message ----- From: Charles Suprin To: Jeff Yanko Cc: Joe ; Gary "Joe" Mayfield ; AMSAT-BB Sent: Thursday, October 01, 2009 1:09 PM Subject: Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
Howdy Jeff,
Someone asked and here we go. A file attachment follows.
Actually the diplexer looks pretty good. Less than half a db of loss at VHF and around half a dB at UHF. I checked the calibration and that was within tenth of a dB over the entire range.
Any questions.
Charles AA1VS
On Sat, Sep 26, 2009 at 6:26 AM, Jeff Yanko wb3jfs@cox.net wrote:
Hi Joe and all,
I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never receive a signal! :)
I believe somebody here on the -bb will be performing a test on the Arrow diplexer using a vector/network analyzer. It will be interesting to say the least. There were preliminary reports saying the device had a loss anywhere from 2.65 to 2.80dB. That's close enough to 3dB which is technically half power loss. Add the loss of a short piece of coax and it will certainly be pushed over the 3dB line.
If I recall correctly, cross polarity is also a 3dB loss. I have noticed that when I rotate the antenna I might get a stronger downlink but I never lose it when I rotate it back. Before, when I would do that it would drop once I rotated in either direction from the peak signal. Basically what is going on is the lossy device is removed and replaced with a more efficient one, that extra net gain you just boosted now shows how the system on the antenna side of the diplexer is truly performing.
I don't have an antenna analysis program to perform a test, but what does a 7 element 440 yagi pattern look like and what is its overall gain?
What we need to do is break down the antenna configuration into 3 segments, see what their losses and gains are then combine them for the overall figure. The 3 segment would be the antenna, the diplexer and the coax. Each one will be tested individually to give an accurate number for each.
73,
Jeff WB3JFS ----- Original Message -----
From: "Joe" nss@mwt.net To: "Gary "Joe" Mayfield" gary_mayfield@hotmail.com Cc: "'AMSAT-BB'" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:42 PM Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE
as in the texts below, there is something else going on here.
That Diplexor can not be all that bad. two reasons.
How many db down is the front to side of that antenna?
and I can not imaging someone would sell a diplexor that has greater than 20 db of losses.
because of the statement that how criticalpolarity was with the original, and now the antenna has to be nearly 90 degrees cross polarized to make it drop out uhh
that close to 30 db,
at least 20,,
something else is going on here
Gary "Joe" Mayfield wrote:
Another issue I came across was how wide the beamwidth is of the
Arrow
Antenna between the Arrow diplexer and the new diplexer. I was
wondering
if
this was going to happen and it did. The reason that this happened
was
with
the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the
signal.
Now, with the new diplexer, you can point the beam in the general
direction
and still copy the bird. In most cases I had to turn the beam 90
degrees
before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without
dropouts
or fades. Makes sense. What I've regained over the lossy diplexer
makes
up
for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how
much
this
system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
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author.
Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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author.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the
author.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date: 09/25/09 17:52:00
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the
author.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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Hi Bruce and all,
No problem. Actually, I wouldn't call it research as much as curiosity. Maybe the research will come later when developing something better. :) I know the antenna "works" but can it be made to perform better? The antenna itself is of great quality and workmanship, it's the diplexer that has been making me wonder if that is the weak spot. The Achilles heel of the system.
OK on setting up the FT-817 using two coaxes. I've heard a number of others doing the same thing with great results. I would suggest doing what best suits the individuals needs and affordability. You be surprised what one can dream up when you plan it out and follow through with the design.
73,
Jeff WB3JFS
----- Original Message ----- From: "Bruce Robertson" ve9qrp@gmail.com To: "Jeff Yanko" wb3jfs@cox.net Cc: "AMSAT-BB" amsat-bb@amsat.org Sent: Friday, September 25, 2009 6:53 AM Subject: Re: [amsat-bb] Arrow antenna reconfiguration results - UPDATE
Jeff --
I really appreciate you doing this research for us. Two additional ideas come to mind:
1. Those of us with FT-817s could configure its two RF ports to use different bands and connect the rig directly to the beam's antenna connectors, bypassing the duplexer. For this purpose, higher-quality bnc terminated cable would be useful.
2. If I'm correct, your replacement duplexer is rather larger than the one it is replacing. It would be a great topic for a Journal article if someone with the necessary equipment and expertise were to design a replacement with less loss.
73, Bruce VE9QRP
On Fri, Sep 25, 2009 at 6:10 AM, Jeff Yanko wb3jfs@cox.net wrote:
Hi all,
A quick update to my new project to improving the Arrow antenna, efficiency wise. I wanted to see how well it would perform on gaining and losing access during AOS and LOS. AO-27 is not a good choice since the timer is turned on when it is well above the AOS horizon and it is switched off before it reaches its LOS horizon. That leaves a dependable AO-51 to test it out.
With the last setup, the OEM diplexer provided by Arrow Antenna, I would copy AO-51 about 3 minutes after AOS and lose it about 3 to 4 minutes before LOS. Not bad, but people were saying they worked the birds when they were 1 degree off of the horizon. I have some pine trees that could be an issue but they are spaced far enough apart that I can work between them and I also have to deal with the McCollough Range to the SSE of me here in Las Vegas, NV. Today, there were 2 passes of AO-51, one at 12 degrees elevation, the other at 74 degrees. During both passes, I began to copy the downlink about a 1.25 minute after AOS. A considerable difference from 3 minutes. The downlink also improved down to about minute before LOS. On the last pass I worked KG6NUB at 0124z and LOS was 0125z and my downlink sounded fairly good, though I was fighting desense. (That's another issue I need to resolve.) Also, on both passes, I never once lost the downlink. No dropouts or fades. I'm still amazed.
Another issue I came across was how wide the beamwidth is of the Arrow Antenna between the Arrow diplexer and the new diplexer. I was wondering if this was going to happen and it did. The reason that this happened was with the old diplexer, the signal attenuated so much that you had to be pointed right smack dab on the bird, a few degrees off and you lost the signal. Now, with the new diplexer, you can point the beam in the general direction and still copy the bird. In most cases I had to turn the beam 90 degrees before I completely lost the downlink! Twisting the antenna to make polarization changes makes absolutely no difference now. This also attributes to the fact that now I'm copying the entire pass without dropouts or fades. Makes sense. What I've regained over the lossy diplexer makes up for any polarization differences, etc. for a better copiable signal.
Next weekend I will have to try more passes and get a feel of how much this system has changed.
73,
Jeff WB3JFS Las Vegas, NV DM26
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participants (11)
-
Alan VE4YZ -
Andrew Rich -
Art McBride -
Bruce Robertson -
Charles Suprin -
Edward Cole -
Gary "Joe" Mayfield -
i8cvs -
James Duffey -
Jeff Yanko -
Joe