1st April 2016 - Analogue input?

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1st April 2016 - Analogue input?

Post by admin » Fri Apr 01, 2016 10:32 am

Following many requests, we are investigating adding analogue input on the same frequency.

Obviously this needs an additional receiver and associated logic changes, but think it will help anyone that already has 'dis-used' analogue kit for 23cm. :D The output will remain digital.


UPDATE: 25th April 2016

I am slowly getting things organised for the analogue input which is progressing.

I dug out my very good analogue receiver for the project, and it no longer worked!! It was worth repairing since it is (was) a top end Echostar LT8700 which if anyone knows the model, has low threshold tuner module fitted - ideal for the repeater :D

Once I had delved into the power supply which appeared to be working initially, the problem turned out to be a CPU reset line from the power supply which was not sensing the outputs correctly (which were present and correct) and shutting down the CPU. Having located and replaced a leaky surface mount 10nf capacitor on the underside of the power supply, it promptly burst into life and is now fully working again.

We have also bought a very low insertion loss splitter which will be used in the 1276Mhz receive path to split the receive signal into two.

Last thing to be worked on is the new logic to not only detect the digital lock signal, but also sense a valid receive signal on analogue, then switch between the two along with the standby camera/testcard etc.

73s Kay

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