What preamp to use for SO-50 and Arrow II antenna?
Since a lot of people are talking about SO-50 right now, let me ask a question:
I did try to work SO-50 once when all I had ever worked before was SO-35, UO-14 and AO-27 and I was horrified by how hard it was to hear and track.
I found a thread on qrz.com where they said it's very helpful to use a preamp for SO-50 since it's so low power, even with the short runs of coax required for an Arrow II satellite antenna. I know almost nothing about preamps. What's the deal? Do they need power to work (active/passive?). What do you recommend?
John Brier, KG4AKV, Raleigh, NC, FM05
I use a High Sierra Microwave LNAA432 preamp powered by a 11.1v LiPo battery pack (AAs or AAAs work fine too). I can work SO-50 down to the horizon with the Arrow Antenna if I have a clear shot. I lost at about a degree on the pass earlier. It's usually S1-2 below a couple of degrees, S7 above 10 degrees, and my FT-817 shows S+ above 30 degrees or so.
You have to be careful not to transmit into a receive only preamp like this. I use two FT-817s, one for receive and one for transmit, so this is not a problem for me, but if you use a single radio, you would need to be sure that the preamp is between the 70cm antenna connection and the diplexer so you don't fry it.
73,
Paul, N8HM
On Thu, Apr 30, 2015 at 11:49 PM, John Brier johnbrier@gmail.com wrote:
Since a lot of people are talking about SO-50 right now, let me ask a question:
I did try to work SO-50 once when all I had ever worked before was SO-35, UO-14 and AO-27 and I was horrified by how hard it was to hear and track.
I found a thread on qrz.com where they said it's very helpful to use a preamp for SO-50 since it's so low power, even with the short runs of coax required for an Arrow II satellite antenna. I know almost nothing about preamps. What's the deal? Do they need power to work (active/passive?). What do you recommend?
John Brier, KG4AKV, Raleigh, NC, FM05 _______________________________________________ Sent via AMSAT-BB@amsat.org. 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
Thanks, I found that at their website:
http://www.hsmicrowave.com/Amateur%20LNA.html
I'm going to use two radios so that won't be an issue.
Man, so they do require power, or at least this one does.
I'm already starting to get tired of trying to track the satellites with the Arrow II. Adding a preamp with a battery pack and a second radio (I've mostly just been listening to the ISS lately) is going to get even more cumbersome, plus you have to operate two radios while compensating for doppler, right? How do you operate portably with your FT-817s? Do you attach one to each hip?! I'm starting to think about circularly polarized antennas I can just set and forget, but with a low power satellite like SO-50 that might not work so well. Hmm.
On Fri, May 1, 2015 at 12:00 AM, Paul Stoetzer n8hm@arrl.net wrote:
I use a High Sierra Microwave LNAA432 preamp powered by a 11.1v LiPo battery pack (AAs or AAAs work fine too). I can work SO-50 down to the horizon with the Arrow Antenna if I have a clear shot. I lost at about a degree on the pass earlier. It's usually S1-2 below a couple of degrees, S7 above 10 degrees, and my FT-817 shows S+ above 30 degrees or so.
You have to be careful not to transmit into a receive only preamp like this. I use two FT-817s, one for receive and one for transmit, so this is not a problem for me, but if you use a single radio, you would need to be sure that the preamp is between the 70cm antenna connection and the diplexer so you don't fry it.
73,
Paul, N8HM
On Thu, Apr 30, 2015 at 11:49 PM, John Brier johnbrier@gmail.com wrote:
Since a lot of people are talking about SO-50 right now, let me ask a question:
I did try to work SO-50 once when all I had ever worked before was SO-35, UO-14 and AO-27 and I was horrified by how hard it was to hear and track.
I found a thread on qrz.com where they said it's very helpful to use a preamp for SO-50 since it's so low power, even with the short runs of coax required for an Arrow II satellite antenna. I know almost nothing about preamps. What's the deal? Do they need power to work (active/passive?). What do you recommend?
John Brier, KG4AKV, Raleigh, NC, FM05 _______________________________________________ Sent via AMSAT-BB@amsat.org. 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
The inaugural edition of Radcom Plus came out today, and the first article is on building a 2m masthead preamp - the DG8. I don't think it's particularly appropriate for handheld use, but looks interesting in that it uses (cheaper) mains relays - whilst I've only had a brief scan the article looks really well written and detailed. I've been looking for a cheaper masthead option for 2m to build and so far the relays have always been the significant cost. Power to this one is also over the coax, so it suits me well.
Radcom Plus is available online for RSGB members - http://rsgb.org/main/blog/front-page-news/2015/04/30/radcom-plus-vol-1-1/
No - I don't work for the RSGB - just genuinely impressed!
Best,
Dominic G6NQO
On 1 May 2015, at 05:09, John Brier johnbrier@gmail.com wrote:
Thanks, I found that at their website:
http://www.hsmicrowave.com/Amateur%20LNA.html
I'm going to use two radios so that won't be an issue.
Man, so they do require power, or at least this one does.
I'm already starting to get tired of trying to track the satellites with the Arrow II. Adding a preamp with a battery pack and a second radio (I've mostly just been listening to the ISS lately) is going to get even more cumbersome, plus you have to operate two radios while compensating for doppler, right? How do you operate portably with your FT-817s? Do you attach one to each hip?! I'm starting to think about circularly polarized antennas I can just set and forget, but with a low power satellite like SO-50 that might not work so well. Hmm.
On Fri, May 1, 2015 at 12:00 AM, Paul Stoetzer n8hm@arrl.net wrote: I use a High Sierra Microwave LNAA432 preamp powered by a 11.1v LiPo battery pack (AAs or AAAs work fine too). I can work SO-50 down to the horizon with the Arrow Antenna if I have a clear shot. I lost at about a degree on the pass earlier. It's usually S1-2 below a couple of degrees, S7 above 10 degrees, and my FT-817 shows S+ above 30 degrees or so.
You have to be careful not to transmit into a receive only preamp like this. I use two FT-817s, one for receive and one for transmit, so this is not a problem for me, but if you use a single radio, you would need to be sure that the preamp is between the 70cm antenna connection and the diplexer so you don't fry it.
73,
Paul, N8HM
On Thu, Apr 30, 2015 at 11:49 PM, John Brier johnbrier@gmail.com wrote: Since a lot of people are talking about SO-50 right now, let me ask a question:
I did try to work SO-50 once when all I had ever worked before was SO-35, UO-14 and AO-27 and I was horrified by how hard it was to hear and track.
I found a thread on qrz.com where they said it's very helpful to use a preamp for SO-50 since it's so low power, even with the short runs of coax required for an Arrow II satellite antenna. I know almost nothing about preamps. What's the deal? Do they need power to work (active/passive?). What do you recommend?
John Brier, KG4AKV, Raleigh, NC, FM05 _______________________________________________ Sent via AMSAT-BB@amsat.org. 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 AMSAT-BB@amsat.org. 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 Dominic
I can recommend that device in the preamp. It's the same one that's used in the AMSAT-UK FUNcube dongle preamp. - But very nice to have the TX/RX switching as well
Thanks for the link
David G0MRF
-----Original Message----- From: Dominic Hawken dominic@del.co.uk To: AMSAT BB amsat-bb@amsat.org Sent: Fri, 1 May 2015 12:23 Subject: Re: [amsat-bb] What preamp to use for SO-50 and Arrow II antenna?
The inaugural edition of Radcom Plus came out today, and the first article is on building a 2m masthead preamp - the DG8. I don't think it's particularly appropriate for handheld use, but looks interesting in that it uses (cheaper) mains relays - whilst I've only had a brief scan the article looks really well written and detailed. I've been looking for a cheaper masthead option for 2m to build and so far the relays have always been the significant cost. Power to this one is also over the coax, so it suits me well.
Radcom Plus is available online for RSGB members - http://rsgb.org/main/blog/front-page-news/2015/04/30/radcom-plus-vol-1-1/
No - I don't work for the RSGB - just genuinely impressed!
Best,
Dominic G6NQO
On 1 May 2015, at 05:09, John Brier johnbrier@gmail.com wrote:
Thanks, I found that at their website:
http://www.hsmicrowave.com/Amateur%20LNA.html
I'm going to use two radios
so that won't be an issue.
Man, so they do require power, or at least
this one does.
I'm already starting to get tired of trying to track the
satellites
with the Arrow II. Adding a preamp with a battery pack and a
second
radio (I've mostly just been listening to the ISS lately) is going
to
get even more cumbersome, plus you have to operate two radios while
compensating for doppler, right? How do you operate portably with your
FT-817s? Do you attach one to each hip?! I'm starting to think about
circularly polarized antennas I can just set and forget, but with a
low power
satellite like SO-50 that might not work so well. Hmm.
On Fri,
May 1, 2015 at 12:00 AM, Paul Stoetzer n8hm@arrl.net wrote:
I use a High
Sierra Microwave LNAA432 preamp powered by a 11.1v LiPo
battery pack (AAs or
AAAs work fine too). I can work SO-50 down to the
horizon with the Arrow
Antenna if I have a clear shot. I lost at about
a degree on the pass
earlier. It's usually S1-2 below a couple of
degrees, S7 above 10 degrees,
and my FT-817 shows S+ above 30 degrees
or so.
You have to be
careful not to transmit into a receive only preamp like
this. I use two
FT-817s, one for receive and one for transmit, so this
is not a problem for
me, but if you use a single radio, you would need
to be sure that the preamp
is between the 70cm antenna connection and
the diplexer so you don't fry
it.
73,
Paul, N8HM
On Thu, Apr 30, 2015 at 11:49 PM,
John Brier johnbrier@gmail.com wrote:
Since a lot of people are talking
about SO-50 right now, let me ask a question:
I did try to work SO-50
once when all I had ever worked before was
SO-35, UO-14 and AO-27 and I was
horrified by how hard it was to hear
and track.
I found a thread
on qrz.com where they said it's very helpful to use a
preamp for SO-50
since it's so low power, even with the short runs of
coax required for an
Arrow II satellite antenna. I know almost nothing
about preamps. What's the
deal? Do they need power to work
(active/passive?). What do you
recommend?
John Brier, KG4AKV, Raleigh, NC, FM05
_______________________________________________
Sent via
AMSAT-BB@amsat.org. 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 AMSAT-BB@amsat.org.
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 AMSAT-BB@amsat.org. 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
John, No doubt a pre-amp would help immensely. However, I don't useone when portable since my feedline is less than 10 feet long. Themore important thing is to be able to change your polarity to matchthat of the Satellite. Mismatched polarity can degrade the signal bymore than 20 dB. I seldom have trouble hearing SO-50 as long asI keep up with the tumbling of the bird. 73/GL, Bob K8BL From: John Brier johnbrier@gmail.com To: AMSAT BB amsat-bb@amsat.org Sent: Thursday, April 30, 2015 11:49 PM Subject: [amsat-bb] What preamp to use for SO-50 and Arrow II antenna?
Since a lot of people are talking about SO-50 right now, let me ask a question:
I did try to work SO-50 once when all I had ever worked before was SO-35, UO-14 and AO-27 and I was horrified by how hard it was to hear and track.
I found a thread on qrz.com where they said it's very helpful to use a preamp for SO-50 since it's so low power, even with the short runs of coax required for an Arrow II satellite antenna. I know almost nothing about preamps. What's the deal? Do they need power to work (active/passive?). What do you recommend?
John Brier, KG4AKV, Raleigh, NC, FM05 _______________________________________________ Sent via AMSAT-BB@amsat.org. 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'm a complete rookie at this, so take it for what it's worth, but I must agree with Bob K8BL. I use an Arrow antenna and the reception is usually 59+ if you have the antenna pointed AND tilted (for polarity) in the right direction. On low angles, reception can go from 59 to null just by rotating the antenna 90 degrees.
Steve AI9IN
On Fri, May 1, 2015 at 12:33 PM, R.T.Liddy k8bl@ameritech.net wrote:
John, No doubt a pre-amp would help immensely. However, I don't useone when portable since my feedline is less than 10 feet long. Themore important thing is to be able to change your polarity to matchthat of the Satellite. Mismatched polarity can degrade the signal bymore than 20 dB. I seldom have trouble hearing SO-50 as long asI keep up with the tumbling of the bird. 73/GL, Bob K8BL From: John Brier johnbrier@gmail.com To: AMSAT BB amsat-bb@amsat.org Sent: Thursday, April 30, 2015 11:49 PM Subject: [amsat-bb] What preamp to use for SO-50 and Arrow II antenna?
Since a lot of people are talking about SO-50 right now, let me ask a question:
I did try to work SO-50 once when all I had ever worked before was SO-35, UO-14 and AO-27 and I was horrified by how hard it was to hear and track.
I found a thread on qrz.com where they said it's very helpful to use a preamp for SO-50 since it's so low power, even with the short runs of coax required for an Arrow II satellite antenna. I know almost nothing about preamps. What's the deal? Do they need power to work (active/passive?). What do you recommend?
John Brier, KG4AKV, Raleigh, NC, FM05 _______________________________________________ Sent via AMSAT-BB@amsat.org. 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 AMSAT-BB@amsat.org. 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 (6)
-
David G0MRF -
Dominic Hawken -
John Brier -
Paul Stoetzer -
R.T.Liddy -
Steve Kristoff