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Message started by abdiasis on Jan 9th, 2017 at 8:49am

Title: RX AGC alarm
Post by abdiasis on Jan 9th, 2017 at 8:49am
Dear sir

How would you clear AGC alarm in RX path of the earth station.

AGC alarm indicates RX signal out range. either too high outside limits or too low and distorted. Also invalid RX signal.

I would appreciate if you help me find more about this type of alarm and how you would clear.

From feed horn i have LNA. cable goes from LNA to ANASAT transceiver. Then transceiver IFRX port goes to modem. The AGC alarm is recorded in RX

Thanks

Title: Re: RX AGC alarm
Post by Admin1 on Jan 9th, 2017 at 3:47pm
The AGC alarm will normally go out as soon as the wanted carrier is received at an acceptable level.

What does the signal look like on spectrum analyser ?

Maybe too high level, too low level, distorted, not tuned correctly?

Are you pointed at the correct satellite ?

Do you have correct polarisation ?

Is the LNB DC supply and 10 MHz reference(if used) turned ON.

What does the carrier look like on a spectrum analyser ?

Is it of the expected bandwidth and level ?

Have you tuned the modem to the carrier frequency.

Have you calculated the L-band cable IF frequency correctly ?

Is the carrier actually being transmitted from the other end ?

Best regards, Eric.



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