[MRCA] [MMRCG] GRC-19 on the air
B. Smith
smithab11 at comcast.net
Sun Jan 4 22:08:54 EST 2026
The Collins PTO assembly utilized in the T-195 is a great performer. I
get all most 8 volts PP out it and it easily drives my Northern 105 FSK
on 80 meters. Caution if you remove the PTO assembly from the T-195
chassis be very careful with the shaft. Support the shaft with a bracket.
Z
On 1/4/2026 1:18 PM, Ray Fantini via MRCA wrote:
> 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
>
>
>
> ______________________________________________________________
> MRCA mailing list
> Home:http://mailman.qth.net/mailman/listinfo/mrca
> Help:http://mailman.qth.net/mmfaq.htm
> Post:mailto:MRCA at mailman.qth.net
>
> This list hosted by:http://www.qsl.net
> Please help support this email list:http://www.qsl.net/donate.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20260104/b72a3963/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PTOk4che.jpg
Type: image/jpeg
Size: 199708 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20260104/b72a3963/attachment-0001.jpg>
More information about the MRCA
mailing list