[ARC5] Transmitter problem found

[Jack Antonio]

I was checking my collection of SCR-274N transmitters,
and came across a BC-457 that was off frequency, high
by about 250 kc, and low in power, about 3 watts.
Since it was otherwise in good shape I decided to fix it.

After some troubleshooting, the problem was found to be
one bad 1625. Actually replaced both, and it was on frequency
and put out about 40 watts.

I know that in these MOPA transmitters the PA circuit
has a big effect on the oscillator, but I was surprised
by how much of a frequency change was caused by the bad tube.

Hope this helps someone else avoid some headscratching.

Jack

Jack Antonio WA7DIA
scr287 at sbcglobal.net