Re: uBitx V3 low power continues

Ashhar Farhan
 

Ted,
The CW is generated independent of the IF and audio system. On the other hand the receiver is working, this rules out any problem in the RF mixer or the low pass filter. 
You must concentrate on the transmitter drivers and PA. The trouble is with those stages. Do you have access to an oscilloscope?

- f

On Sat 2 Nov, 2019, 6:44 PM Ted via Groups.Io, <k3rta=yahoo.com@groups.io> wrote:
Ashhar,

Yes, the receive is spectacular, with an added RFpreamp installed.  I can pick up whatever my Kenwood TS130S can hear. 

Please note the very low SSB modulation in comparison with a tune/CW note. I'd expect a fully-modulated "FIIIIIVVVE" to be aroud the same 'scope width as a CW note, give or take; my SSB is no more than about 25-30% of that with a compressor in line that had worked perfectly until I let the magic out somewhere along the way.

I was thinking "balanced mixer out of whack" or some such, though my theory isn't up to date.  Now, I asked about circuits prior to Q90 because this wide disparity between SSB peak envelope and CW occurs before that, hence my thought that the
problem could preceed this stage.

Thank you, sir, for any further thoughts on the subject.

Ted
K3RTA

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