Im having really poor luck with my inverted V antenna.. its not very high up but only on a very high pass will it hear the beacon on 29.502. What is every one else using?
-Steve Raas N2JDQ FN20vg AMSAT 36396
I just bought a 10 meter preamp from Advanced Receiver Research. I was planning on making a 10 meter dipole and feeding the voltage supply for the mast mounted preamp up the coax. Will this be enough to hear the bird?
----- Original Message ----- From: [email protected] To: [email protected] Sent: Friday, February 02, 2007 11:18 PM Subject: [amsat-bb] AO-07 Downlink Antenna
Im having really poor luck with my inverted V antenna.. its not very high up but only on a very high pass will it hear the beacon on 29.502. What is every one else using?
-Steve Raas N2JDQ FN20vg AMSAT 36396 _______________________________________________ Sent via [email protected]. 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
At 11:18 PM 2/2/2007, [email protected] wrote:
Im having really poor luck with my inverted V antenna.. its not very high up but only on a very high pass will it hear the beacon on 29.502. What is every one else using?
Hi Steve,
For field day, I use a 4-foot telescoping whip with a loading coil mounted on the ground and an ARR preamp right at the antenna. Works great and is very portable.
AO-07 is not very difficult to hear and in general, any vertical antenna will work fine. You could even retune a CB whip for 29 MHz. Verticals do not need to be mounted high to achieve a low angle of radiation unlike an inverted-V.
73, Tony AA2TX
With my ARR 28 MHz preamp sitting here beside me and plenty of plans for antennas, I have a few more questions:
1) Can I really pick up AO-7 with my antique Allied Communications tube receiver if I put the preamp at the antenna?
2) How much EIRP do I need on the uplink? Can I use my IC-706 barefoot, or am I looking at a Mirage amp? I think the 706 puts out 50 watts on 2 meters. I'd probably be using a 3 element beam for uplink with something like 9? db gain. I think I saw something like a 90 watt EIRP would be sufficient for the uplink.
Thanks for everyones help so far!
73 DE KM3G Tyler
3) Do I really gain a few more db in gain if I suffer while I put the antenna up in the supercold weather here in PA, or is that just an urban myth? :-)
I used to operate RS-10/11, RS-12/13, and RS-15 with a Drake T-4XB driving a Drake TC-2 transmit converter, putting out about 40 watts to a homebrew turnstile (later, to an Eggbeater), and the matching Drake R-4B and a simple dipole in the attic (no preamp) for the mode A downlink. Also had the Drake SC-2 receive converter for modes T and KT... Made lots of Q's with some people who were very amused at my "hollow state" station! Not sure if your Allied receiver is quite as stable as the R-4B was after it had warmed up for a half hour or so, but hey, my first SSTV and RTTY SWL'ing was with an old Hallicrafters S-41G (talk about drift...) and a Radio Shack Color Computer...
73, George, KA3HSW
----- Original Message ----- From: "Tyler Harpster" [email protected] To: [email protected] Sent: Tuesday, February 06, 2007 9:49 PM Subject: [amsat-bb] AO-07 RX - TX more questions...
With my ARR 28 MHz preamp sitting here beside me and plenty of plans for antennas, I have a few more questions:
- Can I really pick up AO-7 with my antique Allied Communications tube
receiver if I put the preamp at the antenna?
- How much EIRP do I need on the uplink? Can I use my IC-706 barefoot,
or am I looking at a Mirage amp? I think the 706 puts out 50 watts on 2 meters. I'd probably be using a 3 element beam for uplink with something like 9? db gain. I think I saw something like a 90 watt EIRP would be sufficient for the uplink.
Thanks for everyones help so far!
73 DE KM3G Tyler
- Do I really gain a few more db in gain if I suffer while I put the
antenna up in the supercold weather here in PA, or is that just an urban myth? :-)
Sent via [email protected]. 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
Tyler - To answer your questions:
"1) Can I really pick up AO-7 with my antique Allied Communications tube receiver if I put the preamp at the antenna?"
1. Yes. You should be able to even use the preamp at the receiver, as the sky temperature is pretty high and transmission line loss is not too great, particularly if you use RG-213 or equivalent. I haven't worked Mode A on Oscar 7 this time around, but 25 years ago I received it quite nicely with an old FT-101E with a CB preamp of unknown pedigree at the receiver. The antenna was a loop tacked to the ceiling of the shack with about 10 feet of RG8X. I never had trouble hearing the satellite. This was in LA county, so local noise was pretty high.
"2) How much EIRP do I need on the uplink? Can I use my IC-706 barefoot, or am I looking at a Mirage amp? I think the 706 puts out 50 watts on 2 meters. I'd probably be using a 3 element beam for uplink with something like 9? db gain. I think I saw something like a 90 watt EIRP would be sufficient for the uplink."
The 706 barefoot should be fine, at least on CW. I used to work the satellite with an old Ameco TX62 feeding a 1/4 wave ground plane at the end of 50 feet of RG8X. That is probably 20 - 25 Watts EIRP. I had to turn down the drive on the TX62 to march the beacon, so I was running less power. I suspect that you can run SSB with your setup no problem though. Just remember to keep your downlink signal weaker than the beacon.
"3) Do I really gain a few more db in gain if I suffer while I put the antenna up in the supercold weather here in PA, or is that just an urban myth? :-)"
That is an urban myth. I know, having installed a 160M antenna in -10 F weather in SD one year as a foolish youth. - Dr. Megacycle KK6MC/5
_______________________________________________ Sent via [email protected]. 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
-- James Duffey KK6MC/5 Cedar Crest NM 87008 DM65
participants (5)
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Anthony Monteiro -
George Henry -
James Duffey -
sraasï¼ optonline.net -
Tyler Harpster