[MRCA] PRC-25's converted to PRC-77's: (was Re: CH-54 -> CAP Radios 50 years ago)

[Mkdorney]

One of the things I used to check in on from time to time was the shop that used to do all of our radio repairs, tuning, and maintenance. I’ll get right to the point. There were no vacuum tubes in any of our battalion’s PRC-77 radios, even the couple that still had PRC-25 data plates, period. There was also no vacuum tube test equipment left in Shop B when I visited back in the mid to late 1980’s. I know because I managed to purchase the last tube tester that had been in Shop B’s inventory in 1987. No, these PRC-25s were that in name only. They were all converted to entirely solid state before 1987. 

Mark D. 

“In matters of style, float with the current. In matters of Principle, stand like a rock. “.   -   Thomas Jefferson 

Sent from my iPhone

> On Sep 5, 2019, at 1:31 PM, Tim <timsamm at gmail.com> wrote:
> 
> Thanks Mark - Starting to make sense... I think what you probably had were RT-505B/PRC-25 radios.  There was a "B" modification of the  basic PRC-25 to enable wideband audio/digital/crypto to incorporate the radio into the AN/PCC-1 system.  300 - 20 kc wide audio bandwidth...It could handle multi channel voice and digital baseband signals simultaneously.  The RT-505B modification retained the vacuum tube PA stage and its HV oscillator to generate the 125 VDC necessary to power the tube.
> 
> I thought only the USMC had those, the one I have was modified at the USMC Barstow facility and it was retagged RT-505B/PRC-25.   Interesting that the Army had those as well - it's usually the other way around!
> 
> I have some additional info on that audio/IF amp/IF Filter modification and the peripheral system equipment on my website if you're interested:  
> http://www.n6cc.com/prc-25-radio
> 
> Thanks!  Tim
> N6CC
> 
>> On Thu, Sep 5, 2019 at 4:58 AM WW2RDO via MRCA <mrca at mailman.qth.net> wrote:
>> KY-38 NESTOR was long gone from the inventory when I served.  We used KY-57 VINCENT with our PRC-77s
>> 
>> 
>> While tagged as PRC-25 radios, all of our radios were actually PRC-77s  The PRC-25s had been electronically upgraded, and all our radios tuned to use the KY-57 and were used with our Light TACFIRE system.
>> 
>> Mark D.
>> WW2RDO
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