Re: Terrestrial QRM to FM satellites
Hello all. I, too, have noticed this happen. I saw it first at the Rochester Hamfest this year when Rich N2SPI was giving his demo on the birds (...this is how I became interested in ham sats). During his excellent demo, two hams were chatting about pizza, and the like. I can recall this happening during the Mode K Russian sat days. Quite honestly, I think it's rude and selfish that any person would not follow a gentleman's agreement bandplan. (Reminds me of a local guy about 15 years ago that would talk to his buddies on 144.000 FM.)
It's sad, really.
John KB2HSH
Yes, it *is* sad. We had a packet DX cluster on the ISS uplink here in SoCal several years ago, and the guy would NOT move. He's gone now, but I don't know what happened to him. Jim KQ6EA --- "John Marranca, Jr" [email protected] wrote:
Hello all. I, too, have noticed this happen. I saw it first at the Rochester Hamfest this year when Rich N2SPI was giving his demo on the birds (...this is how I became interested in ham sats). During his excellent demo, two hams were chatting about pizza, and the like. I can recall this happening during the Mode K Russian sat days. Quite honestly, I think it's rude and selfish that any person would not follow a gentleman's agreement bandplan. (Reminds me of a local guy about 15 years ago that would talk to his buddies on 144.000 FM.)
It's sad, really.
John KB2HSH
-- _______________________________
John Marranca, Jr PBX Technician/Shop Steward CWA 1122 BN Systems, Inc Orchard Park, NY (716)972-2006 _______________________________________________ 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 and all,
There are apparently several stations. I heard a part of a call "?A9??" on voice and at another time "/R" on CW on the 20:00Z pass of AO-27 over the US. Someone else was complaining of a strong unmodulated carrier for awhile. I guess I'll have to set the computer up to start recording. I doubt it's malicious. Hopefully it's just "I didn't know". But, as time passes, they will perceive ownership of the frequency, of course.
Bob
--- "John Marranca, Jr" [email protected] wrote:
Hello all. I, too, have noticed this happen. I saw it first at the Rochester Hamfest this year when Rich N2SPI was giving his demo on the birds (...this is how I became interested in ham sats). During his excellent demo, two hams were chatting about pizza, and the like. I can recall this happening during the Mode K Russian sat days. Quite honestly, I think it's rude and selfish that any person would not follow a gentleman's agreement bandplan. (Reminds me of a local guy about 15 years ago that would talk to his buddies on 144.000 FM.)
It's sad, really.
John KB2HSH
-- _______________________________
John Marranca, Jr PBX Technician/Shop Steward CWA 1122 BN Systems, Inc Orchard Park, NY (716)972-2006 _______________________________________________ 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
There are apparently several stations.
How sure is everyone that the QRM is on the uplink frequency? I have noticed some QRM, but it's usually MUCH stronger than the downlink, and will almost always completely over power the satellite signal. I've just assumed that it's local 70cm activity from some locals who don't know any better.
Scott NW2S
No, it's certain that it's on the uplink. The weaker stations are having trouble getting in, and the signals disappear when the satellite pass is over. The strength of the signal is closely related to movement of the satellite, and my S-meter doesn't change vs the satellite when the signals are there.
In my case, there is absolutely no local activity on 70cm below 440 that I have been able to find, other than some kind of digipeater, so anything I hear on 70cm is from a satellite.
Bob
--- Scott Wilson [email protected] wrote:
There are apparently several stations.
How sure is everyone that the QRM is on the uplink frequency? I have noticed some QRM, but it's usually MUCH stronger than the downlink, and will almost always completely over power the satellite signal. I've just assumed that it's local 70cm activity from some locals who don't know any better.
Scott NW2S _______________________________________________ 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
Hi!
No, it's certain that it's on the uplink. The weaker stations are having trouble getting in, and the signals disappear when the satellite pass is over. The strength of the signal is closely related to movement of the satellite, and my S-meter doesn't change vs the satellite when the signals are there.
This is the same thing here. In fact, on a couple of occasions, I would call a ham friend who had also worked the same satellite passes to confirm what I heard was something he also heard. As you mentioned, I would hear the other chatter and I could tell it had to be coming from the satellite downlink and not from local simplex activity. The foreign chatter will usually go away as the satellites move northward, but the other stuff has sometimes stayed on AO-27 for most of its 7-minute passes. The QRM would follow the Doppler shift, not stay on one frequency regardless of the satellite's movement.
I remember a couple of weeks back clearly hearing a CW ID on an AO-27 pass. I think I might have that pass recorded at home, and will try to locate that recording. I seem to remember it was a US 9-call.
We in North America don't have it as bad as our Australian and European friends who deal with all sorts of intruders. If the voices are hams mistakenly using a satellite uplink as a local simplex frequency or as part of some repeater/remote-base system, some polite persuasion should be employed before involving the authorities.
Back to work... 73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/
At 06:39 AM 9/21/2007, Scott Wilson wrote:
There are apparently several stations.
How sure is everyone that the QRM is on the uplink frequency? I have noticed some QRM, but it's usually MUCH stronger than the downlink, and will almost always completely over power the satellite signal. I've just assumed that it's local 70cm activity from some locals who don't know any better.
Well, there are ways of telling. Doppler shift is one. Does the QRM follow the Doppler shift? Then there's the issue of uplink interference. If you have a keen ear, it is possible to tell by subtle differences in the audio whether the signal is on the uplink or downlink, especially when you're running headphones. Similarly, it's also possible to tell if you are experiencing downlink problems or if the other station is not making the uplink, if you know what to listen for (without looking at the S meter).
The above (except for Doppler shift, of course) also apply to terrestrial repeaters.
73 de VK3JED http://vkradio.com
On 20 Sep 2007 at 13:19, Bob Stewart wrote:
John and all,
There are apparently several stations. I heard a part of a call "?A9??" on voice and at another time "/R" on CW on the 20:00Z pass of AO-27 over the US. Someone else was complaining of a strong unmodulated carrier for awhile. I guess I'll have to set the computer up to start recording. I doubt it's malicious. Hopefully it's just "I didn't know". But, as time passes, they will perceive ownership of the frequency, of course.
Bob
On the 2000Z AO-27 pass i was on this pass and i hear 2 folks discussing about a hamfest and they seems to be on a trunking system as we can copy clearly the "trunking tone" at the beginning of their transmission. AO-27 was over the eastern side of NA. If someone is aware of an amateur trunking like repeater this can give a clue even if the path of AO-27 was covering near all North America...
P.S. with 50W on a 14 elem cross yagi their signal capture mine!!! at a time!!!
Luc Leblanc VE2DWE RAC CEC Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
--- Luc Leblanc [email protected] wrote:
On the 2000Z AO-27 pass i was on this pass and i hear 2 folks discussing about a hamfest and they seems to be on a trunking system as we can copy clearly the "trunking tone" at the beginning of their transmission. AO-27 was over the eastern side of NA. If someone is aware of an amateur trunking like repeater this can give a clue even if the path of AO-27 was covering near all North America...
I believe that pass went directly over me here in South Bend. So, all things considered, I would think the station is in or near Chicago.
P.S. with 50W on a 14 elem cross yagi their signal capture mine!!! at a time!!!
Much of one of the passes yesterday (can't remember which anymore) was just a dead carrier locking almost everyone out from about mid-pass till the data download.
Luc Leblanc VE2DWE
Nice to contact you yesterday. You ran a pretty good string of contacts. I have you in the log at 2006 and heard you making a bunch on a later pass while I was mostly listening.
73,
Bob - AE6RV
participants (7)
-
Bob Stewart -
Jim Jerzycke -
John Marranca, Jr -
Luc Leblanc -
Patrick STODDARD (WD9EWK/VA7EWK) -
Scott Wilson -
Tony Langdon