For weeks I have been successfully capturing 30-60 telemetry frames per pass on AO-91 and AO-92 with FoxTelem v.1.08z5.
But suddenly, over the past week or two, I'm lucky to capture 10-20 frames in a pass -- sometimes as few as 1 or 2 frames for a 25 degree elevation pass! The eye just doesn't seem to want to lock up, even when the downlink signal is very strong.
Nothing has changed in my station. Is something different with the DUV signals of the satellites, or with the program, or some screwy Windows update, or something else that I'm missing? Anyone else seeing the same? -- Mark D. Johns, KØJM AMSAT Ambassador & News Service Editor Brooklyn Park, MN USA EN35hd ----------------------------------------------- "Heaven goes by favor; if it went by merit, you would stay out and your dog would go in." ---Mark Twain
Hi Mark,
Glad you're collecting frames! I haven't really seen a drop lately-at least I haven't noticed. There is variability, usually due to changes in times of the pass (e.g., is the transmitter even on at very odd hours in the night?), and sometimes they can share a footprint, so you typically get frames from one but not the other. So frames can vary.
I have from time to time seen that a restart of Foxtelem is necessary; I don't do it daily, but close...not sure if the decoder just needs a restart from time to time, or what. It's pretty stable and consistent, for sure. I just do it more often than necessary so I can keep a watch on daily frame rates (basically resetting the counter...)
You can watch what others are getting framewise here (thanks to spiffy coding by Chris AC2CZ!) A bit of clicking and you get an idea of daily/weekly/monthly frames captured.
http://www.amsat.org/tlm/leaderboard.php?id=0&db=FOXDB
Hope it clears up for you. Not sure this was any help, but I tried ;)
73,
Mark L. Hammond [N8MH] AMSAT Director and Command Station
On Thu, Jun 11, 2020 at 1:27 PM Mark Johns, K0JM via AMSAT-BB < [email protected]> wrote:
For weeks I have been successfully capturing 30-60 telemetry frames per pass on AO-91 and AO-92 with FoxTelem v.1.08z5.
But suddenly, over the past week or two, I'm lucky to capture 10-20 frames in a pass -- sometimes as few as 1 or 2 frames for a 25 degree elevation pass! The eye just doesn't seem to want to lock up, even when the downlink signal is very strong.
Nothing has changed in my station. Is something different with the DUV signals of the satellites, or with the program, or some screwy Windows update, or something else that I'm missing? Anyone else seeing the same? -- Mark D. Johns, KØJM AMSAT Ambassador & News Service Editor Brooklyn Park, MN USA EN35hd
"Heaven goes by favor; if it went by merit, you would stay out and your dog would go in." ---Mark Twain _______________________________________________ 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: https://www.amsat.org/mailman/listinfo/amsat-bb
--
So first, to answer your question, afaik, there has been no change in the satellite downlink.
My "catch" also varies, but it usually depends on the orbit and the timing (lots fewer people on in the middle of the night, and thus less time that the transmitter is on).
However, you said that your eye does not seem to "lock up" despite a strong signal. Does that mean that you see a big "bump" on the frequency (FFT) display, but you do not see an eye? Or you see an eye but no new frames?
If you don't see an eye, I might suspect that the frequency is off. Either your SDR's local oscillator has changed a bit or if you are using "FoxTelem Calculates Doppler" your keps are getting way out of date. They should be updated regularly, but you never know. It should also not be all that fussy with FM satellites, but again...YNNK.
If you do see a good eye, watch at the bottom. You will see light numbers that say "errors" and "erasures". At least you will see them on the frames that you get. It would be interesting to know how high those are. For a good strong signal, it should be in the single digits. If it is a bigger number, that is probably one level of explanation.
Also, how high is the noise floor and the peak signal on your FFT display? Too high can be as bad as too low. You might play with your preamp (if any) and the LNA and Mixer Gain within the FunCubeDongle (check boxes on the "input' page of FoxTelem)
Good luck and 73,
Burns WB1FJ
On Thu, Jun 11, 2020 at 2:25 PM Mark L. Hammond via AMSAT-BB < [email protected]> wrote:
Hi Mark,
Glad you're collecting frames! I haven't really seen a drop lately-at least I haven't noticed. There is variability, usually due to changes in times of the pass (e.g., is the transmitter even on at very odd hours in the night?), and sometimes they can share a footprint, so you typically get frames from one but not the other. So frames can vary.
I have from time to time seen that a restart of Foxtelem is necessary; I don't do it daily, but close...not sure if the decoder just needs a restart from time to time, or what. It's pretty stable and consistent, for sure. I just do it more often than necessary so I can keep a watch on daily frame rates (basically resetting the counter...)
You can watch what others are getting framewise here (thanks to spiffy coding by Chris AC2CZ!) A bit of clicking and you get an idea of daily/weekly/monthly frames captured.
http://www.amsat.org/tlm/leaderboard.php?id=0&db=FOXDB
Hope it clears up for you. Not sure this was any help, but I tried ;)
73,
Mark L. Hammond [N8MH] AMSAT Director and Command Station
On Thu, Jun 11, 2020 at 1:27 PM Mark Johns, K0JM via AMSAT-BB < [email protected]> wrote:
For weeks I have been successfully capturing 30-60 telemetry frames per pass on AO-91 and AO-92 with FoxTelem v.1.08z5.
But suddenly, over the past week or two, I'm lucky to capture 10-20
frames
in a pass -- sometimes as few as 1 or 2 frames for a 25 degree elevation pass! The eye just doesn't seem to want to lock up, even when the
downlink
signal is very strong.
Nothing has changed in my station. Is something different with the DUV signals of the satellites, or with the program, or some screwy Windows update, or something else that I'm missing? Anyone else seeing the same? -- Mark D. Johns, KØJM AMSAT Ambassador & News Service Editor Brooklyn Park, MN USA EN35hd
"Heaven goes by favor; if it went by merit, you would stay out and your dog would go in." ---Mark Twain _______________________________________________ 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: https://www.amsat.org/mailman/listinfo/amsat-bb
-- _______________________________________________ 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: https://www.amsat.org/mailman/listinfo/amsat-bb
Hi Mark,
Not sure what your RF device is. I have seen windows change the audio gain settings when it installs an update. It enables AGC for the FCD or it resets the gain level. The signal ends up too strong and does not decode because it distorts.
Otherwise review the method you are using to tune in the signal. Maybe that was reset somehow.
73 Chris G0KLA
On Thu, Jun 11, 2020, 16:16 Burns Fisher via AMSAT-BB [email protected] wrote:
So first, to answer your question, afaik, there has been no change in the satellite downlink.
My "catch" also varies, but it usually depends on the orbit and the timing (lots fewer people on in the middle of the night, and thus less time that the transmitter is on).
However, you said that your eye does not seem to "lock up" despite a strong signal. Does that mean that you see a big "bump" on the frequency (FFT) display, but you do not see an eye? Or you see an eye but no new frames?
If you don't see an eye, I might suspect that the frequency is off. Either your SDR's local oscillator has changed a bit or if you are using "FoxTelem Calculates Doppler" your keps are getting way out of date. They should be updated regularly, but you never know. It should also not be all that fussy with FM satellites, but again...YNNK.
If you do see a good eye, watch at the bottom. You will see light numbers that say "errors" and "erasures". At least you will see them on the frames that you get. It would be interesting to know how high those are. For a good strong signal, it should be in the single digits. If it is a bigger number, that is probably one level of explanation.
Also, how high is the noise floor and the peak signal on your FFT display? Too high can be as bad as too low. You might play with your preamp (if any) and the LNA and Mixer Gain within the FunCubeDongle (check boxes on the "input' page of FoxTelem)
Good luck and 73,
Burns WB1FJ
On Thu, Jun 11, 2020 at 2:25 PM Mark L. Hammond via AMSAT-BB < [email protected]> wrote:
Hi Mark,
Glad you're collecting frames! I haven't really seen a drop lately-at least I haven't noticed. There is variability, usually due to changes
in
times of the pass (e.g., is the transmitter even on at very odd hours in the night?), and sometimes they can share a footprint, so you typically
get
frames from one but not the other. So frames can vary.
I have from time to time seen that a restart of Foxtelem is necessary; I don't do it daily, but close...not sure if the decoder just needs a
restart
from time to time, or what. It's pretty stable and consistent, for sure. I just do it more often than necessary so I can keep a watch on daily
frame
rates (basically resetting the counter...)
You can watch what others are getting framewise here (thanks to spiffy coding by Chris AC2CZ!) A bit of clicking and you get an idea of daily/weekly/monthly frames captured.
http://www.amsat.org/tlm/leaderboard.php?id=0&db=FOXDB
Hope it clears up for you. Not sure this was any help, but I tried ;)
73,
Mark L. Hammond [N8MH] AMSAT Director and Command Station
On Thu, Jun 11, 2020 at 1:27 PM Mark Johns, K0JM via AMSAT-BB < [email protected]> wrote:
For weeks I have been successfully capturing 30-60 telemetry frames per pass on AO-91 and AO-92 with FoxTelem v.1.08z5.
But suddenly, over the past week or two, I'm lucky to capture 10-20
frames
in a pass -- sometimes as few as 1 or 2 frames for a 25 degree
elevation
pass! The eye just doesn't seem to want to lock up, even when the
downlink
signal is very strong.
Nothing has changed in my station. Is something different with the DUV signals of the satellites, or with the program, or some screwy Windows update, or something else that I'm missing? Anyone else seeing the
same?
-- Mark D. Johns, KØJM AMSAT Ambassador & News Service Editor Brooklyn Park, MN USA EN35hd
"Heaven goes by favor; if it went by merit, you would stay out and your dog would go in." ---Mark Twain _______________________________________________ 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: https://www.amsat.org/mailman/listinfo/amsat-bb
-- _______________________________________________ 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: https://www.amsat.org/mailman/listinfo/amsat-bb
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: https://www.amsat.org/mailman/listinfo/amsat-bb
Good afternoon everyone,
I'm trying to research what heavy duty Azimuth & Elevation rotators are out there in the mark to hold a 4m dish.
Like the one in the below link from SPID.
https://www.thedxshop.com/rotators/spid-big-ras-heavy-duty-azimuth-elevation...
I do know that Alfa-SPID also make one.
The motor/controller needs to run with PSTRotator & PCSAT32. (I run both)
73
Pete
vk2pet
participants (5)
-
Burns Fisher -
Chris Thompson -
Mark Johns, K0JM -
Mark L. Hammond -
Pete vk2pet