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Old July 12th 06, 12:35 AM posted to rec.radio.amateur.boatanchors
K3HVG K3HVG is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 123
Default anyone using R-392/T-195 ???

Steve, I'm currently running a "B" model, here. My particular unit
runs about 120 watts output on AM, and a touch more on CW. Both my
GRC-19's came from a surplus dealer in Scranton, PA. I was able to get
spare/replacement HV/LV power supplies from Baran's Surplus, also in PA.
They also have racks. I do know that they told me last year that they
have not located more of the HV supplies. A straight T-195, with both
dynamotors requires about 44 amps running current. That's not too bad
but its the starting/inrush current that's a bear! I measured my
original T-195 at 97 amps inrush. Power supplies like the PP-4763 just
won't hold the load. Using parallel batteries does not help this
particular supply, either. The best thing to do is find one with (at
least) the HV power supply solid-state module. The LV dynamotor isn't
too bad. The servo system in these transmitters require a solid 28.5-29
volts to make them run properly. Less voltage and they simply won't
tune-up. Changing the discriminator diodes can help, a lot. In fact,
the TM calls for regular change-out of these matched diodes. Relays and
connectors can be problematic in units that have been sitting around for
a while, and not in use. If you get a T-195 and find you need a
replacement special discriminator chopper, I have a good stock of them.
Blowers are critical to proper operation and can be a source of failure.
Early T-195's use a straight 28v blower; later A's and B's use an a.c.
blower and an inverter card to drive them. FYI, both can be retrofitted
with a blower removed from an junked ARC-27 UHF transceiver. The final
and modulator tubes, the 28v 4X150D, are still available but require a
bit of looking, at times. Fair Radio did have overhauled PA modules
with the tube. Use of a headset is all but mandatory given the
high-level blower noise... its impressive!! Front panel meters can be a
problem, too. Many transmitters had the meters removed prior to surplus
action. The multi-meter can be replaced with any of the military
miniature 1ma movements. The modulation meter is, in reality an a.c. VU
meter. I've used a 100ua or 1ma movement driven by a diode bridge
circuit and voltage divider (pot). One can calibrate the meter and it
works just fine. Another tip is to drill out holes in the side of the
transmitter outer cover so access can readily be made for modulation and
sidetone levels. Its a pain to undo a million hex nuts avery time you
need to make a simple adjustment. Oh yeah.... there's a safety
interlock on the rear of the transmitter. If you need to run the tx out
of the case, its necessary to pull it out (on) to activate the tx. Be
sure and get the correct book for whichever variant you end up with.
There are sufficient differences that require it. Also, the TMs have an
error regarding the primary power relay wiring. I fought that one for a
few days before discovering the error. The tx uses 4AG type fuses which
are unobtainium, at least for me. You can, however, carefully reform
the fuse clips so that 3AG types can be used. Lets see... what else.
Oh.. try and find the blower outlet hose adaptors to use instead of the
deflector blocks. Its a lot quieter and you don't have hot air blowing
on your face. Fair Radio has the connectors to make up a dogbone if you
don't already have one. Well, that's about all I can think of, off the
top. I like my set-up here and get on with the East-Coast MIL net with
regularity. Let me know if you have any questions I may be able to help
with. I don't know it all but I have been down the road with this
equipment. Jeep/K3HVG