[MRCA] [MMRCG] GRC-19 on the air

Sun Jan 4 13:18:53 EST 2026

At the time that radio was designed Collins was in love with four band multipliers and the PTO with the idea that nothing beats the stability or quality of there sealed PTO.
The PTO operates in a fixed band; think on the T-195 it's 1.5 to 3.0 MHz, and they have a system of four buffer multipliers to get the other frequencies. Start by checking the accuracy of the PTO on 2.00 MHz and that’s where you want to make any mechanical correction. Any error in band one will be multiplied in the higher bands! Don’t try changing to make something look correct on eighty or forty, do all alignment on band 1. More modern transceivers used converters and the like, but you were unable to get the wide coverage without using that approach back in the fifties. Collins used the same approach on the T-368 and ARC-38
Another thing to look at is if you have the solid-state inverters or the mechanical dynamotors. There is a huge advantage in having the solid-state inverters over the mechanical dynamotors when it comes to starting current. Talked with old timers who used the GRC-19 back in the sixties and they tell me it can easily slow down if not outright stall a M-38 unless you were driving over thirty miles an hour or had the throttle set way high when keyed.
With the solid state inverters, you can run all day long with a PP-8474 power supply and with the dynamotors if you can find a PP-1104 battery charger – Power supply that will do the job. The PP-1104 can also do fun stuff like start an M-151 or M-38 or your daily driver. They can usually be had for cheap but at 110 Lbs. you don’t want to ship it.

Ray F/KA3EKH

________________________________
From: MMRCG at groups.io <MMRCG at groups.io> on behalf of Jason Sogolow via groups.io <w6iee.73=gmail.com at groups.io>
Sent: Sunday, January 4, 2026 11:47 AM
To: scottjohnson1 at cox.net <scottjohnson1 at cox.net>
Cc: MMRCG at groups.io <MMRCG at groups.io>; mrca at mailman.qth.net <mrca at mailman.qth.net>; mrcg-west at groups.io <mrcg-west at groups.io>
Subject: Re: [MMRCG] GRC-19 on the air

Welll, turns out the dial error is different, almost half, on 75M vs 40M.

On Sat, Jan 3, 2026 at 12:13 <scottjohnson1 at cox.net<mailto:scottjohnson1 at cox.net>> wrote:

Jason-

Assuming the error is uniform up and down the band, it is as simple as loosening the coupler on the PTO and moving it in until the display coincides with the frequency.  Ensure all the clamps are tight when you are done.

Regards,

Scott W7SVJ

From: MMRCG at groups.io<mailto:MMRCG at groups.io> <MMRCG at groups.io<mailto:MMRCG at groups.io>> On Behalf Of Jason Sogolow via groups.io<http://groups.io/>
Sent: Saturday, January 3, 2026 12:58 PM
To: mmrcg at groups.io<mailto:mmrcg at groups.io>; mrca at mailman.qth.net<mailto:mrca at mailman.qth.net>; mrcg-west at groups.io<mailto:mrcg-west at groups.io>
Subject: [MMRCG] GRC-19 on the air

Finally lugged the GRC-19 set I got from the estate at the 2024 MRCG West meet up onto a bench… ibuprofen. Had successfully tested the two R-392’s separately last weekend.

Opened the. T-195 up, had a look, did some cursory cleaning and dusting despite being pretty clean in there. Mainly looking for things that might go sizzle or bang.

Then concocted  power source. I have an unknown and untested PP4763, but if I believe the ratings, trying to run it off 120VAC would make my home’s feeble electrical system go sizzle and bang, unless I jumped through the hoops of getting 240VAC to it, which would have been a project in of itself.

Next best option at hand was a pair of 100AH  LiFePo3 batteries in series. Under the best of circumstances, that’s only going to give me 26 volts and change, not the full 28 as advised by WA7YBS in his excellent article on his website.

Powered up last night into a KW-rated dummy load, read the manual and ascended the not very steep (grunt) learning curve to operate, saw that it was making a bit over 100 Watts, and seemed to be functioning mostly properly.

Only issue is that the T-195 PTO seems to be off frequency, have to set the dial 28 kc low to be on frequency of 7293, our only active Southern and Central CA non-audiophile AM frequency, struck me as a place that wouldn’t clutch pearls over a carbon microphone and dynamotor roar.

This morning with topped-off batteries at the ready, connected to the dipole and had a brief QSO with some of the regulars, as far north as Gilroy, and was also informed I was being heard Q5 on the Northern Utah WebSDR. Was also complimented that my audio sounded far better than any carbon microphone should, not sure if I’m believing that one!

So it’s alive! I just need to come up with a better power source, having a look at that today.

How involved is it to correct the dial error? Or should I just accept that as a quirk of 75 year old unrestored equipment?

Thanks and 73,

Jason WA6BBQ

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