[Elecraft] Tx distortion

[mustang65]

Don,
Thanks for all help.
I have measured on q5,q6,q7 when it been resting over night and when it is
warm
and the difference is smal.

q5 base cold )7,9 varm 7,9
q6 base 1,04 emitter 0,28 varm base 1,03 emitter 031 caculeted gives Ic
200mA Pdissipation 2,8W

q7 cold bas 0,658    varm 0,647
All in ssb with no modulation.

I looked with he scope on the base of q5,q6,q7 on the3.8 MHz signal in
tuning
and on  q5 I have a nice sinuswave but on q6 it lookslike a sampled digital
sinuswave
a sinus stairway. On q7 base the positiv side hase roud sinuswave form but
the negativ
side is like a saw vawe sharp edge.
Maybe the scope loads the signal down I do not no the cap. of the probe but
guess it is
about 16pF.

The strange thing is way there is almost no distotion when it been resting
over the night
but comes in after a couple of minutes transmitting.
I put it out in the cold for a while but the distortion was still there even
if it was cold
so it do  not looks like it is the temp more like a old care battery that
almost empty but will
get back a little power resting a night even if you do not charge it.

I have replaced the electrolytic caps on
the ksb2 board but can there be bad caps on the controlboard
that effects transmitt but maybe receive just a little?

I been thinking if there is a problem with the bfo or vco it should effect
Rx as mutch as Tx.

73 Mike sm3xgm






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