AO-7 broadband noise in passband.
I have been observing AO-7 quite a bit lately and I have noticed three broadband humps in my panadapter display. I also see these in W5RKN panadapter captures at:
https://drive.google.com/file/d/0B-Jez46MB5RaMzV0RlhmWHNWcjg/view?usp=sharin...
This confirms these are being transmitted from AO-7. They disappear immediately after the mode switch in his captures. I also observed this today at 31 MAY 2017 about 19:03 UTC during a mode switch.
Does anyone have an explanation of why these occur? The obvious might be some sort of signals on the uplink. Has anyone identified if these signals occur throughout the world or just in specific areas. If you look at these, a large part of AO-7's power output is being used to transmit the broadband humps.
73, Bill NJ1H
They are definitely internally generated. Someone who's been around longer might be able to say if they've been there since the beginning or if they're possibly the result of intern circuit degradation of some type.
Incidentally, the noise peaks coincide with the most sensitive parts of the transponder. The middle is the weakest.
73,
Paul, N8HM
On Thu, Jun 1, 2017 at 00:02 Bill Bordy, NJ1H [email protected] wrote:
I have been observing AO-7 quite a bit lately and I have noticed three broadband humps in my panadapter display. I also see these in W5RKN panadapter captures at:
https://drive.google.com/file/d/0B-Jez46MB5RaMzV0RlhmWHNWcjg/view?usp=sharin...
This confirms these are being transmitted from AO-7. They disappear immediately after the mode switch in his captures. I also observed this today at 31 MAY 2017 about 19:03 UTC during a mode switch.
Does anyone have an explanation of why these occur? The obvious might be some sort of signals on the uplink. Has anyone identified if these signals occur throughout the world or just in specific areas. If you look at these, a large part of AO-7's power output is being used to transmit the broadband humps.
73, Bill NJ1H
Sent via [email protected]. 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
This has been well documented from the earliest days of AO-7 in the 1970s. They occur throughout the world.
73, Gabe NJ7H
On May 31, 2017, at 11:02 PM, Bill Bordy, NJ1H [email protected] wrote:
I have been observing AO-7 quite a bit lately and I have noticed three broadband humps in my panadapter display. I also see these in W5RKN panadapter captures at:
https://drive.google.com/file/d/0B-Jez46MB5RaMzV0RlhmWHNWcjg/view?usp=sharin...
This confirms these are being transmitted from AO-7. They disappear immediately after the mode switch in his captures. I also observed this today at 31 MAY 2017 about 19:03 UTC during a mode switch.
Does anyone have an explanation of why these occur? The obvious might be some sort of signals on the uplink. Has anyone identified if these signals occur throughout the world or just in specific areas. If you look at these, a large part of AO-7's power output is being used to transmit the broadband humps.
73, Bill NJ1H
Sent via [email protected]. 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
Which mode are you seeing the humps?
Joe WB9SBD Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 5/31/2017 11:02 PM, Bill Bordy, NJ1H wrote:
I have been observing AO-7 quite a bit lately and I have noticed three broadband humps in my panadapter display. I also see these in W5RKN panadapter captures at:
https://drive.google.com/file/d/0B-Jez46MB5RaMzV0RlhmWHNWcjg/view?usp=sharin...
This confirms these are being transmitted from AO-7. They disappear immediately after the mode switch in his captures. I also observed this today at 31 MAY 2017 about 19:03 UTC during a mode switch.
Does anyone have an explanation of why these occur? The obvious might be some sort of signals on the uplink. Has anyone identified if these signals occur throughout the world or just in specific areas. If you look at these, a large part of AO-7's power output is being used to transmit the broadband humps.
73, Bill NJ1H
Sent via [email protected]. 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
participants (4)
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Bill Bordy, NJ1H -
Gabriel Zeifman -
Joe -
Paul Stoetzer