Chirp can be caused by different causes.

1. The crystal may simply change frequency when first loaded. Try a
different crystal, or try the crystal in a different transmitter.

2. Feedback may be incorrect. Too much feedback can cause chirp.
Depending upon the circuit, you can change feedback by varying the
capacitance between grid and cathode.

3. Voltage stabilization. A stable voltage is less likely to chirp.
Sometimes varying the screen voltage will help make the oscillator less
likely to drift.

Draw your circuit out and match it to one in the older Radio Amateur
Handbook. Oscillator circuits are as simple as the Model T.

Colin K7FM


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zeno wrote:
On closer examination again, I do now see a couple of small diodes (both have
the number 205) which were hiding behind some black spaghetti pushed up against
them. This little homebrew seems to have been carefully assembled and I have no
reason to believe that the 6L6 is not the correct tube. The little rig does
work, but, as mentioned, the CW note was quite distorted and unacceptable. How
would one go about trouble shooting this problem. At this point I have limited
bench equipment , but might consider acquiring some. An oscilloscope is high on
the want list. Can you point to a part of the circuit which would result in
this very chirpy and wobbly CW tone. I would have to fire it up again to
remember how best to describe the sound of this signal.

Bill K6TAJ

The very first place to go is to check all of the chassis
grounds. If solder lugs are screwed to the chassis, loosen them and
then retighten them. If the octal tube socket has a ground ring, and metal
ears as many do, loosen its screws, and retighten them. Clean and lube the
wipers of any trimmer caps or air variable tuning caps. Clean up the pins
and socket for the crystal. Next would be any electrolytics in the circuit.
And, of course, any paper capacitors. If there are any "dogbone" resistors,
get rid of them and replace them with "modern" carbon composition resistors.

A lot of faults can be found by just listening to the note on a receiver,
and wiggling stuff around.

-Chuck Harris

zeno wrote:
On closer examination again, I do now see a couple of small diodes (both have
the number 205) which were hiding behind some black spaghetti pushed up against
them. This little homebrew seems to have been carefully assembled and I have no
reason to believe that the 6L6 is not the correct tube. The little rig does
work, but, as mentioned, the CW note was quite distorted and unacceptable. How
would one go about trouble shooting this problem. At this point I have limited
bench equipment , but might consider acquiring some. An oscilloscope is high on
the want list. Can you point to a part of the circuit which would result in
this very chirpy and wobbly CW tone. I would have to fire it up again to
remember how best to describe the sound of this signal.

Bill K6TAJ

The very first place to go is to check all of the chassis
grounds. If solder lugs are screwed to the chassis, loosen them and
then retighten them. If the octal tube socket has a ground ring, and metal
ears as many do, loosen its screws, and retighten them. Clean and lube the
wipers of any trimmer caps or air variable tuning caps. Clean up the pins
and socket for the crystal. Next would be any electrolytics in the circuit.
And, of course, any paper capacitors. If there are any "dogbone" resistors,
get rid of them and replace them with "modern" carbon composition resistors.

A lot of faults can be found by just listening to the note on a receiver,
and wiggling stuff around.

-Chuck Harris