[ARC5] T-19 Update

[David Stinson]

I just helped a fellow (who shall go nameless) trouble-shoot 
his 274N set-up with "no power out."
We fixed multiple problems but, with the Oscillator 
clear in a monitor receiver and everything seeming "right,"
he still had no power out.  Turned-out to be a shorted
coax jumper.  Happens to me, too.

One thing we ran into before the bad jumper-
there was a bad pin at the modulator and the rigs
were not getting Osc. B+.  
Keying without Osc. means no bias on the finals.
This condition opened the "no bias" protection fuse.

On top of the big RF Choke that feeds the PA plates,
there should be a doo-hicky about the size of 
a 1-watt resistor that  looks like a small coil- 
a ceramic form with solder caps on each end 
and a few turns of wire between them.
This is listed as a resistor (R-76), but it's really a fuse- 
designed specifically to protect the finals
if they lost bias. 
 It should read about 20 ohms if good.
Make sure it's not open.  
If open, make sure your oscillator is running 
and you can temporarily jumper it with any fine wire.  
You can also solder a pig-tailed 1/4 amp fuse there if needed.
This little fuse is under the chassis at the PA tube bases 
in ATA and 274N transmitters.

73 DE Dave AB5S.