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Re: uBITX ... AGC or AVC?

 

Loris,

Try something else..

Use a SBL-1 or similar. DBM. it is a BiDi device

Connect one? RF port to signal INput and second to OUTput or other way.

Feed a DC control voltage through a resistor to the IF port. Try with 1-10K.
Vary the voltage and see the signal level change. The behavior is opposite
of the varicap control voltage.

We can use this for AGC and ALC in either direction.

Raj

At 28/10/2020, you wrote:

On Wed, Oct 28, 2020 at 12:31 PM, Raj vu2zap wrote:
I had experimented with a AGC which was very simple. Disconnect R23 and R43 from ground and introduce
a varicap which I had MV2109. A series resistor to the varicap through which you varied the capacitance
and thereby the gain. This method worked very well with both IF stages and even on the TX branch.

I wish some members would experiment on this approach.

Hello Raj ...
Interesting solution, if I have some free time I could try it!
I would like to have an explanation from you:
what is the function of AGC? transmission for uBITX? ... perhaps as a compressor instead of an external speech-processor?
Thank you, 73 Loris - IW4AJR
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