Diplexer recommendation
Hi all,
I'm slowly assembling my satellite base station setup bit by bit, I have recently mounted an antenna system on my roof consisting of two perpendicular VHF/UHF open-sleeve yagi's mounted at a fixed elevation of 25 degrees on an azimuth rotator, more info here: https://twitter.com/PA3RVG/status/942710621375815680
So I have two feed lines coming into the house, both suitable for VHF and UHF operation. I want to be able to independently select one of the two antennas for RX and TX. This can be realized using two diplexers and two switches, but now for the million dollar question: Which diplexer?
I'm curious to know which diplexers you guys use if you use them, and which can be recommended in terms of insertion loss, VSWR and isolation. If you believe the manufacturer specifications they are all great, but I'm more interested in real life performance or test measurements.
73, Rico PA3RVG
Hi Rico,
So, two questions:
First, what are you planning to use for your radio(s)? I'm a bit puzzled by the need to swap Tx and Rx connections, if you are using a diplexer. And, most of the satellite operations I do involve either two separate radios, or a satellite radio that has separate VHF and UHF antenna connections. In those cases, you'd not need the diplexer at all, since the purpose of a diplexer is to use one feed line to cover two antennas. Could you share your "two diplexers and two switches" diagram?
Second, that's a really cool antenna that you have built. Are the plans available online somewhere?
Greg KO6TH
Rico van Genugten wrote:
Hi all,
I'm slowly assembling my satellite base station setup bit by bit, I have recently mounted an antenna system on my roof consisting of two perpendicular VHF/UHF open-sleeve yagi's mounted at a fixed elevation of 25 degrees on an azimuth rotator, more info here: https://twitter.com/PA3RVG/status/942710621375815680
So I have two feed lines coming into the house, both suitable for VHF and UHF operation. I want to be able to independently select one of the two antennas for RX and TX. This can be realized using two diplexers and two switches, but now for the million dollar question: Which diplexer?
I'm curious to know which diplexers you guys use if you use them, and which can be recommended in terms of insertion loss, VSWR and isolation. If you believe the manufacturer specifications they are all great, but I'm more interested in real life performance or test measurements.
73, Rico PA3RVG _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I reckon the duplexer is required as there is no direct connections to the 70cm antenna.
Brad WF7T
On Jan 8, 2018, 3:20 PM -0600, Greg D [email protected], wrote:
Hi Rico,
So, two questions:
First, what are you planning to use for your radio(s)? I'm a bit puzzled by the need to swap Tx and Rx connections, if you are using a diplexer. And, most of the satellite operations I do involve either two separate radios, or a satellite radio that has separate VHF and UHF antenna connections. In those cases, you'd not need the diplexer at all, since the purpose of a diplexer is to use one feed line to cover two antennas. Could you share your "two diplexers and two switches" diagram?
Second, that's a really cool antenna that you have built. Are the plans available online somewhere?
Greg KO6TH
Rico van Genugten wrote:
Hi all,
I'm slowly assembling my satellite base station setup bit by bit, I have recently mounted an antenna system on my roof consisting of two perpendicular VHF/UHF open-sleeve yagi's mounted at a fixed elevation of 25 degrees on an azimuth rotator, more info here: https://twitter.com/PA3RVG/status/942710621375815680
So I have two feed lines coming into the house, both suitable for VHF and UHF operation. I want to be able to independently select one of the two antennas for RX and TX. This can be realized using two diplexers and two switches, but now for the million dollar question: Which diplexer?
I'm curious to know which diplexers you guys use if you use them, and which can be recommended in terms of insertion loss, VSWR and isolation. If you believe the manufacturer specifications they are all great, but I'm more interested in real life performance or test measurements.
73, Rico PA3RVG _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
But he has two cables going into the antenna (you can see them in the picture).
I'm guessing by his hashtags that one of the radios is an RTLSDR dongle, so I can see the need for two cables and the switching from one "rig" to the other. Presuming the other radio is not full-duplex.
Perhaps the answer is to use 4 switches. One pair for the rigs, the other for the antennas. Hook one side of the switched side directly through, the other cross-connected. Just remember to set all 4 switches properly before transmitting!
Greg KO6TH
Brad Brooks wrote:
I reckon the duplexer is required as there is no direct connections to the 70cm antenna.
Brad WF7T
On Jan 8, 2018, 3:20 PM -0600, Greg D [email protected], wrote:
Hi Rico,
So, two questions:
First, what are you planning to use for your radio(s)? I'm a bit puzzled by the need to swap Tx and Rx connections, if you are using a diplexer. And, most of the satellite operations I do involve either two separate radios, or a satellite radio that has separate VHF and UHF antenna connections. In those cases, you'd not need the diplexer at all, since the purpose of a diplexer is to use one feed line to cover two antennas. Could you share your "two diplexers and two switches" diagram?
Second, that's a really cool antenna that you have built. Are the plans available online somewhere?
Greg KO6TH
Rico van Genugten wrote:
Hi all,
I'm slowly assembling my satellite base station setup bit by bit, I have recently mounted an antenna system on my roof consisting of two perpendicular VHF/UHF open-sleeve yagi's mounted at a fixed elevation of 25 degrees on an azimuth rotator, more info here: https://twitter.com/PA3RVG/status/942710621375815680
So I have two feed lines coming into the house, both suitable for VHF and UHF operation. I want to be able to independently select one of the two antennas for RX and TX. This can be realized using two diplexers and two switches, but now for the million dollar question: Which diplexer?
I'm curious to know which diplexers you guys use if you use them, and which can be recommended in terms of insertion loss, VSWR and isolation. If you believe the manufacturer specifications they are all great, but I'm more interested in real life performance or test measurements.
73, Rico PA3RVG _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer for RX. Good idea to use four switches Greg, in fact that's what I'm currently doing. With four switches you always use one antenna for RX and the other for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select which antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not great in Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
On Mon, Jan 8, 2018 at 11:04 PM, Greg D [email protected] wrote:
But he has two cables going into the antenna (you can see them in the picture).
I'm guessing by his hashtags that one of the radios is an RTLSDR dongle, so I can see the need for two cables and the switching from one "rig" to the other. Presuming the other radio is not full-duplex.
Perhaps the answer is to use 4 switches. One pair for the rigs, the other for the antennas. Hook one side of the switched side directly through, the other cross-connected. Just remember to set all 4 switches properly before transmitting!
Greg KO6TH
Brad Brooks wrote:
I reckon the duplexer is required as there is no direct connections to the 70cm antenna.
Brad WF7T
On Jan 8, 2018, 3:20 PM -0600, Greg D [email protected], wrote:
Hi Rico,
So, two questions:
First, what are you planning to use for your radio(s)? I'm a bit puzzled by the need to swap Tx and Rx connections, if you are using a diplexer. And, most of the satellite operations I do involve either two separate radios, or a satellite radio that has separate VHF and UHF antenna connections. In those cases, you'd not need the diplexer at all, since the purpose of a diplexer is to use one feed line to cover two antennas. Could you share your "two diplexers and two switches" diagram?
Second, that's a really cool antenna that you have built. Are the plans available online somewhere?
Greg KO6TH
Rico van Genugten wrote:
Hi all,
I'm slowly assembling my satellite base station setup bit by bit, I
have
recently mounted an antenna system on my roof consisting of two perpendicular VHF/UHF open-sleeve yagi's mounted at a fixed elevation of 25 degrees on an azimuth rotator, more info here: https://twitter.com/PA3RVG/status/942710621375815680
So I have two feed lines coming into the house, both suitable for VHF and UHF operation. I want to be able to independently select one of the two antennas for RX and TX. This can be realized using two diplexers and
two
switches, but now for the million dollar question: Which diplexer?
I'm curious to know which diplexers you guys use if you use them, and which can be recommended in terms of insertion loss, VSWR and isolation. If you believe the manufacturer specifications they are all great, but I'm
more
interested in real life performance or test measurements.
73, Rico PA3RVG _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Rico,
I had used either Comet or Diamond diplexers in the past, until I found the MFJ diplexers were about half the price of the Comet and Diamond units, with what I saw as comparable performance. WiMo in the US is like your description of MFJ in Europe; I've never seen or tried WiMo diplexers.
One review I saw a while back actually showed the MFJ-916B to be much better than Diamond's MX-72:
http://www.w4gso.org/news/comparing-duplexers-mfj-vs-diamond/
The pictures and screenshots aren't in this article, but the text tells the story of this comparison.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Tue, Jan 9, 2018 at 9:42 AM, Rico van Genugten < [email protected]> wrote:
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer for RX. Good idea to use four switches Greg, in fact that's what I'm currently doing. With four switches you always use one antenna for RX and the other for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select which antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not great in Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
Hi all,
Thanks for the recommendation Patrick, I have contacted MFJ and hope they will ship a couple of them to the Netherlands. I have also contacted WiMo for some specs on their diplexers as they aren't available on their website, I will share them on this list when I receive them.
73, Rico PA3RVG
On Tue, Jan 9, 2018 at 4:57 PM, Patrick STODDARD (WD9EWK/VA7EWK) < [email protected]> wrote:
Rico,
I had used either Comet or Diamond diplexers in the past, until I found the MFJ diplexers were about half the price of the Comet and Diamond units, with what I saw as comparable performance. WiMo in the US is like your description of MFJ in Europe; I've never seen or tried WiMo diplexers.
One review I saw a while back actually showed the MFJ-916B to be much better than Diamond's MX-72:
http://www.w4gso.org/news/comparing-duplexers-mfj-vs-diamond/
The pictures and screenshots aren't in this article, but the text tells the story of this comparison.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Tue, Jan 9, 2018 at 9:42 AM, Rico van Genugten < [email protected]> wrote:
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer for RX. Good idea to use four switches Greg, in fact that's what I'm currently doing. With four switches you always use one antenna for RX and the other for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select which antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not great in Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
Page 10 of PA1IVO's presentation at the 2011 AMSAT-UK Colloquium includes measurements of the Wimo Diplexer. It appears to have very good specs in general, though it looks like losses were measured at 1.45 dB at 436 MHz, which is a bit high.
https://ivok.home.xs4all.nl/pa1ivo/doc/AmsatColloquium2011.pdf
73,
Paul, N8HM
On Tue, Jan 9, 2018 at 11:16 AM, Rico van Genugten [email protected] wrote:
Hi all,
Thanks for the recommendation Patrick, I have contacted MFJ and hope they will ship a couple of them to the Netherlands. I have also contacted WiMo for some specs on their diplexers as they aren't available on their website, I will share them on this list when I receive them.
73, Rico PA3RVG
On Tue, Jan 9, 2018 at 4:57 PM, Patrick STODDARD (WD9EWK/VA7EWK) < [email protected]> wrote:
Rico,
I had used either Comet or Diamond diplexers in the past, until I found the MFJ diplexers were about half the price of the Comet and Diamond units, with what I saw as comparable performance. WiMo in the US is like your description of MFJ in Europe; I've never seen or tried WiMo diplexers.
One review I saw a while back actually showed the MFJ-916B to be much better than Diamond's MX-72:
http://www.w4gso.org/news/comparing-duplexers-mfj-vs-diamond/
The pictures and screenshots aren't in this article, but the text tells the story of this comparison.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Tue, Jan 9, 2018 at 9:42 AM, Rico van Genugten < [email protected]> wrote:
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer for RX. Good idea to use four switches Greg, in fact that's what I'm currently doing. With four switches you always use one antenna for RX and the other for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select which antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not great in Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I use diamond mx72n pair to allow a 100 ft run from shack to antennas using 7/8" hardline. .1db loss and plenty of power at 400/250w fm. isolation of the units back to back is 120db uhf/vhf which is plenty to run satellite with two radios and two antennas.
On Tuesday, January 9, 2018 10:22 AM, Paul Stoetzer [email protected] wrote:
Page 10 of PA1IVO's presentation at the 2011 AMSAT-UK Colloquium includes measurements of the Wimo Diplexer. It appears to have very good specs in general, though it looks like losses were measured at 1.45 dB at 436 MHz, which is a bit high.
https://ivok.home.xs4all.nl/pa1ivo/doc/AmsatColloquium2011.pdf
73,
Paul, N8HM
On Tue, Jan 9, 2018 at 11:16 AM, Rico van Genugten [email protected] wrote:
Hi all,
Thanks for the recommendation Patrick, I have contacted MFJ and hope they will ship a couple of them to the Netherlands. I have also contacted WiMo for some specs on their diplexers as they aren't available on their website, I will share them on this list when I receive them.
73, Rico PA3RVG
On Tue, Jan 9, 2018 at 4:57 PM, Patrick STODDARD (WD9EWK/VA7EWK) < [email protected]> wrote:
Rico,
I had used either Comet or Diamond diplexers in the past, until I found the MFJ diplexers were about half the price of the Comet and Diamond units, with what I saw as comparable performance. WiMo in the US is like your description of MFJ in Europe; I've never seen or tried WiMo diplexers.
One review I saw a while back actually showed the MFJ-916B to be much better than Diamond's MX-72:
http://www.w4gso.org/news/comparing-duplexers-mfj-vs-diamond/
The pictures and screenshots aren't in this article, but the text tells the story of this comparison.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Tue, Jan 9, 2018 at 9:42 AM, Rico van Genugten < [email protected]> wrote:
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer for RX. Good idea to use four switches Greg, in fact that's what I'm currently doing. With four switches you always use one antenna for RX and the other for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select which antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not great in Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Since I don't believe the isolation numbers, are they measured or claimed?
Bob N4HY
On Tue, Jan 9, 2018 at 12:10 PM, Floyd Rodgers [email protected] wrote:
I use diamond mx72n pair to allow a 100 ft run from shack to antennas using 7/8" hardline. .1db loss and plenty of power at 400/250w fm. isolation of the units back to back is 120db uhf/vhf which is plenty to run satellite with two radios and two antennas.
On Tuesday, January 9, 2018 10:22 AM, Paul Stoetzer <[email protected]>wrote:
Page 10 of PA1IVO's presentation at the 2011 AMSAT-UK Colloquium includes measurements of the Wimo Diplexer. It appears to have very good specs in general, though it looks like losses were measured at 1.45 dB at 436 MHz, which is a bit high.
https://ivok.home.xs4all.nl/pa1ivo/doc/AmsatColloquium2011.pdf
73,
Paul, N8HM
On Tue, Jan 9, 2018 at 11:16 AM, Rico van Genugten [email protected] wrote:
Hi all,
Thanks for the recommendation Patrick, I have contacted MFJ and hope they will ship a couple of them to the Netherlands. I have also contacted WiMo for some specs on their diplexers as they aren't available on their website, I will share them on this list when I receive them.
73, Rico PA3RVG
On Tue, Jan 9, 2018 at 4:57 PM, Patrick STODDARD (WD9EWK/VA7EWK) < [email protected]> wrote:
Rico,
I had used either Comet or Diamond diplexers in the past, until I found the MFJ diplexers were about half the price of the Comet and Diamond units, with what I saw as comparable performance. WiMo in the US is like your description of MFJ in Europe; I've never seen or tried WiMo diplexers.
One review I saw a while back actually showed the MFJ-916B to be much better than Diamond's MX-72:
http://www.w4gso.org/news/comparing-duplexers-mfj-vs-diamond/
The pictures and screenshots aren't in this article, but the text tells the story of this comparison.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Tue, Jan 9, 2018 at 9:42 AM, Rico van Genugten < [email protected]> wrote:
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer
for
RX. Good idea to use four switches Greg, in fact that's what I'm
currently
doing. With four switches you always use one antenna for RX and the
other
for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select
which
antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not
great in
Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I use Comet CF-4160Ns in the VT ground station. A while back (June of 2016) I measured the insertion loss and isolation for a single diplexer with a calibrated Rhode and Schwarz network analyzer 'on the bench' and the numbers are close to the spec (with a 50 Ohm termination on the 'unused' port for the two port measurements of a three port device).
The claimed numbers are 0.1dB for VHF insertion loss, 0.2dB for UHF insertion loss, and a blanket '60 dB' for isolation. In that controlled measurement situation, for the COM to VHF port path (with a 50 termination on the UHF port) I got 0.048 dB of insertion loss at VHF and 59.695 dB of UHF isolation. For the COM to UHF port path (50 ohm termination on the VHF port) I got 0.100 dB of insertion loss at UHF and 73.812 dB of VHF isolation.
So technically the measured performance did better than the claimed performance on everything except the UHF isolation from the VHF port which only missed the claimed spec by about .3 dB (assuming I didn't screw up the cal process).
All of that though, was for a /single/ diplexer.
I'd have to think more about the ganging of two diplexers on either end of the cable and whether or not you'd actually get the full 'double isolation'. Something about that first diplexer and internal coupling or reflected UHF energy if the there is any mismatch causing UHF energy (from say a VHF third harmonic) leaking back into the UHF radio. Maybe not if you have a good match.....but then coupling at the antennas and an LNA with gain in the mix.........interesting problem to fully think through and sort out the details........
On the surface though, if you had two diplexers, one on either side of the cable, and inserted a UHF signal into the VHF port on one side and then measured the UHF signal power on the VHF port of the diplexer on the other side, there would be about 120dB or so of loss in that path (2 times the isolation plus the cable's insertion loss).......just not sure thats an appropriate test considering that's not quite how the actual system is installed when antennas and LNAs and radios are all in the mix and matches aren't all perfect.
Fun stuff to think about though!
-Zach, KJ4QLP
Research Associate Aerospace Systems Lab Ted & Karyn Hume Center for National Security & Technology Virginia Polytechnic Institute & State University Work Phone: 540-231-4174 Cell Phone: 540-808-6305
On 1/9/2018 2:18 PM, Robert McGwier wrote:
Since I don't believe the isolation numbers, are they measured or claimed?
Bob N4HY
On Tue, Jan 9, 2018 at 12:10 PM, Floyd Rodgers [email protected] wrote:
I use diamond mx72n pair to allow a 100 ft run from shack to antennas using 7/8" hardline. .1db loss and plenty of power at 400/250w fm. isolation of the units back to back is 120db uhf/vhf which is plenty to run satellite with two radios and two antennas.
On Tuesday, January 9, 2018 10:22 AM, Paul Stoetzer <[email protected]>wrote:
Page 10 of PA1IVO's presentation at the 2011 AMSAT-UK Colloquium includes measurements of the Wimo Diplexer. It appears to have very good specs in general, though it looks like losses were measured at 1.45 dB at 436 MHz, which is a bit high.
https://ivok.home.xs4all.nl/pa1ivo/doc/AmsatColloquium2011.pdf
73,
Paul, N8HM
On Tue, Jan 9, 2018 at 11:16 AM, Rico van Genugten [email protected] wrote:
Hi all,
Thanks for the recommendation Patrick, I have contacted MFJ and hope they will ship a couple of them to the Netherlands. I have also contacted WiMo for some specs on their diplexers as they aren't available on their website, I will share them on this list when I receive them.
73, Rico PA3RVG
On Tue, Jan 9, 2018 at 4:57 PM, Patrick STODDARD (WD9EWK/VA7EWK) < [email protected]> wrote:
Rico,
I had used either Comet or Diamond diplexers in the past, until I found the MFJ diplexers were about half the price of the Comet and Diamond units, with what I saw as comparable performance. WiMo in the US is like your description of MFJ in Europe; I've never seen or tried WiMo diplexers.
One review I saw a while back actually showed the MFJ-916B to be much better than Diamond's MX-72:
http://www.w4gso.org/news/comparing-duplexers-mfj-vs-diamond/
The pictures and screenshots aren't in this article, but the text tells the story of this comparison.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Tue, Jan 9, 2018 at 9:42 AM, Rico van Genugten < [email protected]> wrote:
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer
for
RX. Good idea to use four switches Greg, in fact that's what I'm
currently
doing. With four switches you always use one antenna for RX and the
other
for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select
which
antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not
great in
Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
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Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Here is another excellent ARRL article back from 2004 about Diplexers: http://www.dci.ca/pdf/qst-dec-2004.pdf I had good experience with the MFJ-916B and got better results compared to the Comet 4160.
Adrian AA5UK
On Tuesday, January 9, 2018, 10:00:30 AM CST, Patrick STODDARD (WD9EWK/VA7EWK) [email protected] wrote:
Rico,
I had used either Comet or Diamond diplexers in the past, until I found the MFJ diplexers were about half the price of the Comet and Diamond units, with what I saw as comparable performance. WiMo in the US is like your description of MFJ in Europe; I've never seen or tried WiMo diplexers.
One review I saw a while back actually showed the MFJ-916B to be much better than Diamond's MX-72:
http://www.w4gso.org/news/comparing-duplexers-mfj-vs-diamond/
The pictures and screenshots aren't in this article, but the text tells the story of this comparison.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK or http://twitter.com/WD9EWK
On Tue, Jan 9, 2018 at 9:42 AM, Rico van Genugten < [email protected]> wrote:
Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer for RX. Good idea to use four switches Greg, in fact that's what I'm currently doing. With four switches you always use one antenna for RX and the other for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select which antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not great in Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (9)
-
Adrian Engele -
Brad Brooks -
Floyd Rodgers -
Greg D -
Patrick STODDARD (WD9EWK/VA7EWK) -
Paul Stoetzer -
Rico van Genugten -
Robert McGwier -
Zach Leffke