Rca 8-pt-7031

[dtvmcdonald]

I tried aligning the IF again (The RF stages were OK to start with). Remember
earlier I had moved the IF up about 3 MHz.

I actually looked carefully at the slugs in the tuner coils and realized that
they were all set on the bottom side of the windings (i.e. partially out
of the windings on the side nearest the chassis.

I tried moving them, one at a time, to the same frequency on the outer side.
This resulted in a similar response. Next I tried aligning at the normal
frequencies. The picture appeared exactly as in the instructions for the
first time! That's an abysmally bad response, nevertheless. I again
tried playing by hand and lo and behold it was easy to get, instead of
the specified peaky response, the usual slope for the vestigial sideband,
then a flat top, followed by a steep drop to 3.5 MHz (from the compulsory
dip caused by the interaction of L47 and L48) and the specified small peak
at the audio carrier.

After reinstalling the CRT HV kludge, I got a perfect picture. Not super
high resolution, of course with both IF and video limited to maybe 2.5 MHz,
but no blurring or ringing. It stays that way from zero to about 85% rotation
of the contrast control.

I love playing with TVs like this! I hope this thread on a super UNexceptional
and UNinteresting (but cute) TV will be of help to somebody in the future.

RCA PT-8-7010 PT-8-7030 PT-8-7011 PT-8-7031 PT87010 PT87011
PT87030 PT87031 PT-8-7030T PT-8-7031T for searchers.