What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
73s John AA5JG
I've been using my BuddiPole. Seems to work OK. Jim KQ6EA
--- On Fri, 9/11/09, John Geiger [email protected] wrote:
From: John Geiger [email protected] Subject: [amsat-bb] Mode A antennas? To: [email protected] Date: Friday, September 11, 2009, 8:32 PM
What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
73s John AA5JG
_______________________________________________ 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
John. I dont know about the G5RV...but at the St. Cloud House in Clear Lake I can hear it with a homemade J Pole, two dipoles 90 degrees to each other and a converted CB whip... The RX is a very well maintained Heath SB 300 and a Radio Shack 10 meter box
At Santa Fe (our "gentlemans farm") not much antennas up yet but pretty good copy on the JPOLE sitting about 10 feet off the ground and a 33 foot dipole N/S about 30 feet off the ground... RX a Drake R-4 and the Radio Shack 10 meter box...
The SB300 and the Drake have preamps in front of them...
make sure it is in Mode A though...
Robert WB5MZO
Date: Fri, 11 Sep 2009 20:32:45 -0700 From: [email protected] To: [email protected] Subject: [amsat-bb] Mode A antennas?
What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
73s John AA5JG
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
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Hello John
This may not apply to you but I'm sure some others will benefit I have a 4 element cubical quad at about 50 feet. It is tuned for about 28.3Mhz. Now at 29.5Mhz the reflector is acting like a director and it actually "hears" better off the back than the front. I noticed this back in the old RS satellite days. The 10M downlink on AO-7 is to say the least, lousy, usually good for CW most of the time. The AO-7 log says it all.
73 Bob W7LRD
Seattle
----- Original Message ----- From: "John Geiger" [email protected] To: [email protected] Sent: Friday, September 11, 2009 8:32:45 PM GMT -08:00 US/Canada Pacific Subject: [amsat-bb] Mode A antennas?
What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
73s John AA5JG
_______________________________________________ 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
On Sat, 2009-09-12 at 04:47 +0000, [email protected] wrote:
Hello John
This may not apply to you but I'm sure some others will benefit I have a 4 element cubical quad at about 50 feet. It is tuned for about 28.3Mhz. Now at 29.5Mhz the reflector is acting like a director and it actually "hears" better off the back than the front.
Wait a sec, how does that work? Surely the reflector is larger than the driven element and is even more "too large" at 29MHz?
Before anyone jumps down my throat, I'm not saying it doesn't work, I'm saying I don't understand how it works... ;-)
Gordon MM0YEQ
Crossed dipoles and a preanp worked for me.
John Geiger wrote:
What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
73s John AA5JG
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
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On Sat, Sep 12, 2009 at 12:32 AM, John Geiger [email protected] wrote:
What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
73s John AA5JG
John --
I have had verticals of heights between 23' and 45' that could hear the 10m downlink, even when connected to 100' of RG-8 and no preamp.
My guess is that your G5RV is highly directional at 10m. Such long doublets develop flower petal lobes of high gain in the horizontal dimension with very deep nulls between them. On HF this isn't such a big issue, since the RF is going *somewhere*: you probably don't care if you work NZ or Australia. (Ok, with the sunspots these days you'd be overjoyed with either.) However, with satellite reception such patterns make reception very difficult. Moreover, your G5RV is likely to be up a good height at 10m, pushing its vertical pattern down to the horizon. So now, to hear this bird, it has to be between, say 5 deg up and 15 deg. up and within the 'petals' of the horizonal pattern.
Here's a situation where less truly might be more. A lowish dipole will reduce the lobes, and crummy vertical will too, though in the other dimension.
Let us know how things work!
73, Bruce VE9QRP
At 11:32 PM 9/11/2009, John Geiger wrote:
What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
73s John AA5JG
Hi John,
I use an MFJ 4-foot, loaded whip feeding an ARR low-noise preamp at the base. Works great.
73, Tony AA2TX
In the past, I have used a 2-element 10 meter yagi.
Unfortunately, a G5RV is a mediocre antenna at best for bands other than 20 meters for which it was actually designed.
Glen, K9STH
Website: http://k9sth.com
--- On Fri, 9/11/09, John Geiger [email protected] wrote:
What is the minimal antenna you can use on 10m to hear the AO7 downlink in Mode A? I have a homebrew G5RV type antenna up and can't hear AO7 on it at all. What kind of antennas are others using on 10m for mode A?
participants (9)
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Anthony Monteiro -
Bruce Robertson -
Glen Zook -
Gordon JC Pearce -
Jim Jerzycke -
John Geiger -
Nigel Gunn G8IFF/W8IFF -
Rocky Jones -
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