AO-51 has been switched to the SSB/FM crossmode repeater, 145.880 USB up, 435.150 FM down. Power output is 1.93 watts. The downlink modulation is set very high, so that even very weak signals will be audible. The downside to this is that someone running excessive power will cause the downlink to distort.If this happens I'll be forced to adjust the modulation level down, or possibly end the mode early. For a "normal" station, 5 watts on the uplink to a modest gain antenna is entirely sufficient. Please use the minimum power necessary. This mode -requires- tuning the SSB uplink precisely for Doppler, and to effectively do that you will need full duplex.
Please use this for voice communications only, until Straight Key Night, when CW will be the designated mode.
Thanks, and enjoy this unusual mode.
73, Drew KO4MA AMSAT-NA VP Operations
Drew,
Thank you for the mode switch, should be fun!! Congratulations on your contacts and analysis for XO-68, your were featured on Amateur Radio Newsline, this evening.
I want to wish you and your family a Healthy and Peaceful New Year.
73, Pete, WB2OQQ AMSAT Area Coordinator
On 28 Dec 2009 at 19:13, Andrew Glasbrenner wrote:
Date sent: Mon, 28 Dec 2009 19:13:24 -0500 From: Andrew Glasbrenner [email protected] Subject: [amsat-bb] AO-51 mode change and recommendation To: Amsat-BB [email protected]
AO-51 has been switched to the SSB/FM crossmode repeater, 145.880 USB up, 435.150 FM down. Power output is 1.93 watts. The downlink modulation is set very high, so that even very weak signals will be audible. The downside to this is that someone running excessive power will cause the downlink to distort.If this happens I'll be forced to adjust the modulation level down, or possibly end the mode early. For a "normal" station, 5 watts on the uplink to a modest gain antenna is entirely sufficient. Please use the minimum power necessary. This mode -requires- tuning the SSB uplink precisely for Doppler, and to effectively do that you will need full duplex.
Please use this for voice communications only, until Straight Key Night, when CW will be the designated mode.
Thanks, and enjoy this unusual mode.
73, Drew KO4MA AMSAT-NA VP Operations _______________________________________________
On the first 3.9 deg morning pass i was able to hear F6BYJ and an ON station my own downlink was quite distorted even with any signal/modulation level.
On the second pass signal peak at S9 plus 20 but my downlink aidio was rather weak. Signal from the satellite was breaking up but i was able to hear my downlink with 5 watts for most of the past but as probably a commanding station was adjusting the levels the near end of the pass my audio became extremely weak and seems to never getting back at the AOS to TCA level.
The first morning low pass audio adjustment produce a very good and clean signal but on the second one audio appears to be muted at AOS to TCA and became extremely muted on the second half on the pass to a point where no communication was possible. It is not a signal problem but just the audio who seems to be adjusted at the right level.
No distortion has been noted too.
The only one problem i was alone for the whole pass speaking to myself...
"-"
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe DSTAR urcall VE2DWE WAC BASIC CW PHONE SATELLITE
Just curious, Why voice only?
Why no CW?
Joe WB9SBD
*The Original Rolling Ball Clock Idle-Tyme.com http://www.idle-tyme.com*
Luc Leblanc wrote:
On 28 Dec 2009 at 19:13, Andrew Glasbrenner wrote:
Date sent: Mon, 28 Dec 2009 19:13:24 -0500 From: Andrew Glasbrenner [email protected] Subject: [amsat-bb] AO-51 mode change and recommendation To: Amsat-BB [email protected]
AO-51 has been switched to the SSB/FM crossmode repeater, 145.880 USB up, 435.150 FM down. Power output is 1.93 watts. The downlink modulation is set very high, so that even very weak signals will be audible. The downside to this is that someone running excessive power will cause the downlink to distort.If this happens I'll be forced to adjust the modulation level down, or possibly end the mode early. For a "normal" station, 5 watts on the uplink to a modest gain antenna is entirely sufficient. Please use the minimum power necessary. This mode -requires- tuning the SSB uplink precisely for Doppler, and to effectively do that you will need full duplex.
Please use this for voice communications only, until Straight Key Night, when CW will be the designated mode.
Thanks, and enjoy this unusual mode.
73, Drew KO4MA AMSAT-NA VP Operations _______________________________________________
On the first 3.9 deg morning pass i was able to hear F6BYJ and an ON station my own downlink was quite distorted even with any signal/modulation level.
On the second pass signal peak at S9 plus 20 but my downlink aidio was rather weak. Signal from the satellite was breaking up but i was able to hear my downlink with 5 watts for most of the past but as probably a commanding station was adjusting the levels the near end of the pass my audio became extremely weak and seems to never getting back at the AOS to TCA level.
The first morning low pass audio adjustment produce a very good and clean signal but on the second one audio appears to be muted at AOS to TCA and became extremely muted on the second half on the pass to a point where no communication was possible. It is not a signal problem but just the audio who seems to be adjusted at the right level.
No distortion has been noted too.
The only one problem i was alone for the whole pass speaking to myself...
"-"
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe DSTAR urcall VE2DWE WAC BASIC CW PHONE SATELLITE
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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Idle-Tyme wrote:
Just curious, Why voice only?
Why no CW?
Joe WB9SBD
*The Original Rolling Ball Clock Idle-Tyme.com http://www.idle-tyme.com*
One, we are setting aside time for CW only on Straight Key Night. Two, there is many times more demand for voice, and mixing modes on a single downlink is problematic.
73, Drew KO4MA
On Dec 29, 2009, at 9:05 AM, Andrew Glasbrenner wrote:
mixing modes on a single downlink is problematic.
73, Drew KO4MA
Drew - Can you expand on this? I got my start on AO-7 Mode A the first time around ca 1980 using an old Ameco TX-62 I purchased for $40 at the TRW swapmeet and made lots of cross mode CW/SSB contacts. As I recall, this was common place and perfectly acceptable in those days, even encouraged, as lots of beginners had CW only by keying the PTT on their 2M FM.
Have times changed? I realize that there aren't a lot of CW ops left these days, but it is still a powerful mode and a good introduction to what can be done with weak signals on a minimal investment. That 10 dB or so SNR advantage really helps.
Don't misunderstand, I am not a CW forever guy and try to be mode agnostic, but I do operate as much CW as any other mode. Having said that, I prefer the linear mode satellites, but that is not a CW/voice issue, but rather what I see as a greater utilization of available resources. But I agree that the FM birds have their place, particularly in seducing beginners to the joys of working others through satellites.
I too am getting back into satellites after a short hiatus, well maybe a long one, I last worked RS12 on Mode A and K. But a new TS-2000X sits in the shack and I am getting the VHF/UHF antennas back up. Listen for me on CW and SSB. Maybe FM as well. Are any digital modes being used? I recall reports in the AMSAT Journal of some successful Hell QSOs a few years back. - Duffey -- KK6MC James Duffey Cedar Crest NM
Drew - Can you expand on this? I got my start on AO-7 Mode A the first time around ca 1980 using an old Ameco TX-62 I purchased for $40 at the TRW swapmeet and made lots of cross mode CW/SSB contacts. As I recall, this was common place and perfectly acceptable in those days, even encouraged, as lots of beginners had CW only by keying the PTT on their 2M FM.
Have times changed? I realize that there aren't a lot of CW ops left these days, but it is still a powerful mode and a good introduction to what can be done with weak signals on a minimal investment. That 10 dB or so SNR advantage really helps.
Don't misunderstand, I am not a CW forever guy and try to be mode agnostic, but I do operate as much CW as any other mode. Having said that, I prefer the linear mode satellites, but that is not a CW/voice issue, but rather what I see as a greater utilization of available resources. But I agree that the FM birds have their place, particularly in seducing beginners to the joys of working others through satellites.
I too am getting back into satellites after a short hiatus, well maybe a long one, I last worked RS12 on Mode A and K. But a new TS-2000X sits in the shack and I am getting the VHF/UHF antennas back up. Listen for me on CW and SSB. Maybe FM as well. Are any digital modes being used? I recall reports in the AMSAT Journal of some successful Hell QSOs a few years back. - Duffey
I'm not about to be lured into the CW/SSB debate. In this particular mode, sharing a single frequency downlink, one really needs to stick with a single common mode. In this case, this time, it's SSB voice, except for SKN, when it's CW. To me, mixing CW and SSB on this particular mode is like mixing SSTV, Voice, and Packet on the regular FM repeater. That wouldn't go over too well either, as we have seen recently with HO-68.
Linear transponders are an entirely different animal, and all your prior experiences hold true there still.
73, Drew KO4MA
I tried the 13:40-ish pass, and also feel that the audio was low...
I'm only working with a quarter-wave ground plane at the moment, and it was only a 10 degree pass for me. I heard a couple of other stations, one of which was off-frequency on the uplink. We'll see what it's like later on a higher pass.
George, KA3HSW
PS - Luc: I heard you come back to me on HO-68 last night, but then there was a deep fade and we never completed our exchanges. (It's a little hard to concentrate on satellite operating when the Bears are actually WINNNG a game...)
----- Original Message ----- From: "Luc Leblanc" [email protected] To: [email protected] Sent: Tuesday, December 29, 2009 4:45 AM Subject: [amsat-bb] Re: AO-51 mode change and recommendation
[snip]
On the first 3.9 deg morning pass i was able to hear F6BYJ and an ON station my own downlink was quite distorted even with any signal/modulation level.
On the second pass signal peak at S9 plus 20 but my downlink aidio was rather weak. Signal from the satellite was breaking up but i was able to hear my downlink with 5 watts for most of the past but as probably a commanding station was adjusting the levels the near end of the pass my audio became extremely weak and seems to never getting back at the AOS to TCA level.
The first morning low pass audio adjustment produce a very good and clean signal but on the second one audio appears to be muted at AOS to TCA and became extremely muted on the second half on the pass to a point where no communication was possible. It is not a signal problem but just the audio who seems to be adjusted at the right level.
No distortion has been noted too.
The only one problem i was alone for the whole pass speaking to myself...
At 11:02 AM 12/29/2009 -0600, "George Henry" [email protected] wrote:
I tried the 13:40-ish pass, and also feel that the audio was low...
I'm only working with a quarter-wave ground plane at the moment, and it was only a 10 degree pass for me. I heard a couple of other stations, one of which was off-frequency on the uplink. We'll see what it's like later on a higher pass.
George, KA3HSW
I listened last night, and that was my thought too. The FM downlink from Echo was twenty over nine, with a lot of white noise in the background much like you hear when listening to a 9600 bps signal, but the audio level of the stations making contacts on it was low. Receiving Echo shouldn't be a problem if the output is lowered, at least for me anyway, but I wonder if it's possible to increase the receiver gain on Echo so SSB signals come out louder. To me it seemed the audio should have been louder as I was receiving the downlink almost full scale.
participants (7)
-
Andrew Glasbrenner -
George Henry -
Idle-Tyme -
James Duffey -
Luc Leblanc -
Peter -
Vince Fiscus, KB7ADL