[NJARC] Repair Clinic

[Robert Flory]

Hi All,

I missed the repair clinic on Saturday, but I have a good excuse.  I was
doing a repair clinic of my own.

With Chris Nardi, curator, I resurrected an RCA-built  WWII Navy TBS set,
VHF AM, on battleship MASSACHUSETTS.

I started as most repairs do, with a recap of the receiver.  At that point
it responded well to the output of an LP signal generator.  I then pushed
START on the transmitter with no response.  Reseating the transmitter, I
pushed start again, and the motor-generator came to life.  I shut down and
a massive hunt for a transmitter crystal followed.  We found a couple much
later, after giving up the search.  I installed one, pushed start, and
after warming up, hit the test key.  NADA.  Since there was no sign of
response to any tuning control, I started at the oscillator, reseating the
807 tube and swapping for the other crystal.  BINGO!  She tuned all the way
through and made an Amp of antenna current into a 50 ohm dummy load.  

Chris went above to try some of the remote controls and found one that
activated the transmitter.  On plugging in a handset, he made some test
transmissions.  I could see the plate current dropping, so I could tell he
was modulating it.  I then had to fix an RBK receiver so we could hear the
transmitter, as the transmitter crystal that worked was on a different
frequency than the receiver.  Heard intelligible signals from the
transmitter, declared victory, and retreated.

That's the meat of the story.  I also activated TAJ and TBM transmitters,
and RBA, RBB, RBC receivers on 500, 3570, and 3885kc.

Rob Flory
robandpj at earthlink.net
www.home.earthlink.net/~navyradio  WWII Navy Radio
www.home.earthlink.net/~robandpj    Les Flory Television and Electronics