[Milsurplus] TRC-10 change

[Hubert Miller]

Was looking at a TRC-10 manual, a really beat up, well used veteran manual, and noticed this.
In the section on vibrator supply, the schematic has drawn in, two additional resistors, each one
from the vibe center pole to one set of contacts. The resistors are 50 ohms and are labeled R301,
R302, which are not in the parts list section. Interesting, I thought. I can't see a post-military user
using the set, except maybe possibly C.A.P., who were given some of these in the late 1940s or
early 1950s. So was this a field mod to suppress sparking at the transformer contacts? There was
already a snubber across the vibe contact for the magnet coil.
I like to think this was a field mod to solve some problem, and not a hammy mod.
I do not have the vibrator supply. I have the A.C. supply. Not exactly happy with it is as; the B+
under no load soars to 880 volts per manual, which I'm thinking is kinda unhealthy. The PA tube
is 2E22. Since this is a CW only transmitter, I changed the tube to 807; only required plate cap
change, and this eliminated the substantial AC hum on signal with the 2E22.
-Hue
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20170910/4b46327b/attachment.html>