Listening for Fox 1E / SDR Receivers Question.
There has been a recent thread about SDR receivers ( unrelated to Fox 1E). I have a yagi/LNA/filter assembly and a feeder to an RSP2 here. On one of the other forums there was a comment about maybe listening for the Fox 1E transponder LO or something other than just the beacon. Is there a detail block diagram available of the transponder that would call out the LO frequency ? (I'm guessing 581.65 MHz if its a single conversion) or any details of the passband filtering? Maybe there is enough LO leakage out the front or back end of the transponder to receive. If there is an AGC/ALC, the TX might be putting out a noise bump that could be seen by the SDR also.
Anyway, just food for thought. Alan VE2NHR
On 1/28/21 12:04 PM, Alan Rich wrote:
for the Fox 1E transponder LO or something other than just the beacon. Is there a detail block diagram available of the transponder that would call out the LO frequency ? (I'm guessing 581.65 MHz if its a single conversion) or any details of the passband filtering? Maybe there is enough LO leakage out the front or back end of the transponder to receive. If there is an AGC/ALC, the TX might be putting out a noise bump that could be seen by the SDR also.
I did not see the linear transponder design or a block diagram in any of the Symposium Proceedings that I have, but someone else on the list might know if this design was ever released as part of the ITAR "data dump" in the Proceedings.
73,
--- Zach N0ZGO
Fox-1E Transponder block diagram is in the 2017 Proceedings. I just checked the hard copy. I'm at work or I would dig out what it says for LO.
73 Chris
On Thu, Jan 28, 2021 at 3:18 PM Zach Metzinger zmetzing@pobox.com wrote:
On 1/28/21 12:04 PM, Alan Rich wrote:
for the Fox 1E transponder LO or something other than just the beacon. Is there a detail block diagram available of the transponder that would call out the LO frequency ? (I'm guessing 581.65 MHz if its a single conversion) or any details of the passband filtering? Maybe there is enough LO leakage out the front or back end of the transponder to receive. If there is an AGC/ALC, the TX might be putting out a noise bump that could be seen by the SDR also.
I did not see the linear transponder design or a block diagram in any of the Symposium Proceedings that I have, but someone else on the list might know if this design was ever released as part of the ITAR "data dump" in the Proceedings.
73,
--- Zach N0ZGO
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On 01/28/21 14:31, Chris Thompson wrote:
Fox-1E Transponder block diagram is in the 2017 Proceedings. I just checked the hard copy. I'm at work or I would dig out what it says for LO.
I pulled my copy out and scanned it. I apologize for the quality.
https://www.n0zgo.net/amsat/fox1e_transponder_sch_symposium_2017.pdf
73,
--- Zach N0ZGO
Note that AMSAT members have access to proceedings going back to 1986. https://launch.amsat.org/Proceedings
de KM1P Joe
https://www.amsat.org/wordpress/wp-content/uploads/2018/06/AMSAT-Fox-Documen...
See page 812. There is some useful info a few pages above and below there.
73 de KE5GDB
On Thu, Jan 28, 2021 at 12:05 PM Alan Rich arich127@gmail.com wrote:
There has been a recent thread about SDR receivers ( unrelated to Fox 1E). I have a yagi/LNA/filter assembly and a feeder to an RSP2 here. On one of the other forums there was a comment about maybe listening for the Fox 1E transponder LO or something other than just the beacon. Is there a detail block diagram available of the transponder that would call out the LO frequency ? (I'm guessing 581.65 MHz if its a single conversion) or any details of the passband filtering? Maybe there is enough LO leakage out the front or back end of the transponder to receive. If there is an AGC/ALC, the TX might be putting out a noise bump that could be seen by the SDR also.
Anyway, just food for thought. Alan VE2NHR
Sent via AMSAT-BB(a)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!
View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/amsat-bb@amsat.org To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org
participants (5)
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Alan Rich -
Andrew Koenig -
Chris Thompson -
Joseph B. Fitzgerald -
Zach Metzinger