Re: Tp20 location on board. Ubitx V6 2 on board.


Owen Vinall
 

Evan,
Thanks for the rapid reply. No wonder I couldn't locate it. I have already built a 1 transistor microphone amp just didn't want to start making changes on a new radio unless I had to that will come soon enough. How did you connect your mike audio output to the Ubitx eg wiring.

Regards
Owen

On Tue, 18 Aug 2020, 9:02 pm Evan Hand, <elhandjr@...> wrote:
Owen,
Here is a picture of a v6 board with the area for TP20 blown up.  Note that it is between the two electrolytic capacitors C52 and C64 and the crystal filter.


The low audio drive is a common problem of the uBITX, going back to the prior versions that I have been following.  I solved it with an amplified "CB" mic, others have used a speech compressor, mic preamp, or added a second 2n3904 in front of the onboard mic amp.  I went with the amplified mic because I did not have to modify anything on the mainboard and it is easier than adding another board in the uBITX case.

You do need to ensure that you do not overdrive the audio, as that will cause all kids of splatter and spurious signals.  Since you said you have an SDR, you should be able to use that to verify your signal purity.

Hope this helps.
73
Evan
AC9TU

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