Fired up our next PSK31 cubesat card for first test and the ground station got full S9 carrier but signal was full of noise totally masking the PSK31 tones.
Turned off. Channel was clear. Then opened squelch and there was S9 noise over 5 Mhz around our UHF downlink.
Went down the halls with HT and signal tapered slowly down in all directions.
Came back and with 1” of wire in the HT antenna connector narrowed it down to a cheap battery charger.
Lesson over and over again, is that a squelch HIDES everything Even 20+S9 noise sources. Zero bars while squelched.
Reminded me of when we had local repeater problems. Turns out it was the megawatt balloon radar operating in VHF looking over Washington DC. No one could hear it with their radio squelched. But open the squelch and every channel throughout 2m would show 60+S9 bars on the noisy trash.
It was similarly baffling at the peak of packet in the 90’s when some hams would complain that their packet system wasn’t working, and yet they never turned up the volume to listen by ear to the channel to see what was going on. I still see that sometimes in our students who think that all you have to do is hook-up two wireless thingy’s and is should just work… but never think to listen to a channel or use a spectrum analyzer to see what they are dealing with.
Turns out, this battery charger (now that I remember) was the SAME one that got me several years ago. I was just too old to remember until I had again done the full DF search through the entire academic building and ended up right back at the same point.
The older we get the more we have to learn over and over again ;-)
Bob, WB4APR
Sounds like it's time to clip the lead on that guy and deposit it in circular file.!
73, Roger W7TZ CN83ia
On Fri, Feb 3, 2017 at 5:57 AM, Robert Bruninga bruninga@usna.edu wrote:
Fired up our next PSK31 cubesat card for first test and the ground station got full S9 carrier but signal was full of noise totally masking the PSK31 tones.
Turned off. Channel was clear. Then opened squelch and there was S9 noise over 5 Mhz around our UHF downlink.
Went down the halls with HT and signal tapered slowly down in all directions.
Came back and with 1” of wire in the HT antenna connector narrowed it down to a cheap battery charger.
Lesson over and over again, is that a squelch HIDES everything Even 20+S9 noise sources. Zero bars while squelched.
Reminded me of when we had local repeater problems. Turns out it was the megawatt balloon radar operating in VHF looking over Washington DC. No one could hear it with their radio squelched. But open the squelch and every channel throughout 2m would show 60+S9 bars on the noisy trash.
It was similarly baffling at the peak of packet in the 90’s when some hams would complain that their packet system wasn’t working, and yet they never turned up the volume to listen by ear to the channel to see what was going on. I still see that sometimes in our students who think that all you have to do is hook-up two wireless thingy’s and is should just work… but never think to listen to a channel or use a spectrum analyzer to see what they are dealing with.
Turns out, this battery charger (now that I remember) was the SAME one that got me several years ago. I was just too old to remember until I had again done the full DF search through the entire academic building and ended up right back at the same point.
The older we get the more we have to learn over and over again ;-)
Bob, WB4APR _______________________________________________ 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
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Robert Bruninga -
Roger