Re: tx pop

Marc Jones
 

Is this Mod for the Bitx-40 of the Micro-Bitx ?  Starting to get a bit of a muddle reading posts now on here , Not knowing what version of BITX there for ..


Mark  'Gw0wvl' ...


On Tue, 9 Jan 2018 at 4:29, Raj vu2zap
<rajendrakumargg@...> wrote:
Farhan,

I have been thinking of diode switching in the audio stages. The TX 12v can block the RX preamp and vice-versa.

I have to get back to town to try!

Raj

At 09/01/2018, you wrote:
>i have been trying to hack out the tx pop. it is a far more intricate problem than it does seem at first. to cut a very long and painful story short, i am not yet there. but i have a partial solution.
>
>add a 470uf (or a 220uf) capacitor in parallel to C50. The C50 is the 1uf capacitor that feeds the detector signal to the audio pre-amp. Increasing this to 470uf, prolongs the 'switch on' time of the audio preamp just enough to not hear the TX-to-RX thump.
>
>can someone else too try this out?
>
>i call it a partial solution because it doesn't suppress the rx-to-tx pop (which is not as bad as the tx-to-rx pop).
>
>- f




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