[Milsurplus] (no subject)

Thu Jan 5 18:47:52 EST 2017

The stand-alone mount for the RT-70 and AM-65 was the MT-791 

I have a large quantity of this kind of stuff for sale including PRC-9 &10,  RT-66, 67 & 68 . BC-659 (2). Russian R-108 (working pair), pair of MT-791, etc., etc.  DVD available on request.

Dennis D. W7QHO
Glendale, CA

*************
> On Jan 5, 2017, at 1:52 PM, Bruce Gentry <ka2ivy at verizon.net> wrote:
> 
> I will ultimately find the needed parts to get the big VRC setup together and working. It used an RT-70 and the amplifier along with an RT 67 or 8, a PP-109 or 112 power supply, and a standalone R-108 or 9 reciver on a common mount. I can imagine the combinations of RTs were almost endless. Why were different corps of the Army on different bands? Were there too few channels? I was a small guy when you worked on these, but I had a screwdriver and pliers in my hands already. These rigs are built to last, and seem to be nearing the ultimate in tube design. How aware were military radio techs at the time about transistors? I wonder if that entire range of VRC/PRC gear was regarded as being the last stand for tubes  with full expectation the next family of replacements would be solid state.
> 
>   Bruce Gentry
> 
> On 1/5/17 2:26 PM, CWH wrote:
>> They were also used  in tanks for communication between infantry and tanks. The AM 65 was used as an interphone amplifier.  I was a radio repairman in a M48 tank company 1953-1955.
>> 73 Charlie W8CFO
>> 
>> -----Original Message----- From: Dennis DuVall
>> Sent: Thursday, January 05, 2017 1:50 PM
>> To: Jack Antonio
>> Cc: milsurplus at mailman.qth.net
>> Subject: Re: [Milsurplus] RT-70
>> 
>> Have several of these.  Don’t recall any particular problems getting the things running but it’s been a while now.
>> Vibrator supplies come in 6, 12 & 24 volt flavors.  Very low power and short range but fun to play with.  Understand
>> they wee used for local area coms until telephone wire could be strung.
>> 
>> Dennis D. W7QHO
>>> On Jan 5, 2017, at 9:34 AM, Jack Antonio <scr287 at att.net> wrote:
>>> 
>>> On 1/4/2017 2:42 PM, Bruce Gentry wrote:
>>>> I'm getting a couple RT-70 transceivers and the matching audio
>>>> amplifier/power supplies working, and need connectors. I also have the
>>> 
>>> 
>>> Problems I had with my RT-70 and AM-65:
>>> 
>>> Either relay K1 or ballast tube R-32 were bad in
>>> the AM-65. Maybe both. This is from 10 year ago
>>> memory, and any notes I took have gone AWOL.
>>> These two components are in an over-voltage protect
>>> circuit, and it was intermittently protecting when
>>> it didn't need to. Of course it worked fine on the
>>> bench, and only cropped up when I took the radio to
>>> MRCG to play with. I found exact replacements,
>>> but from where I don't recall. Possibly Fair or eBay.
>>> 
>>> Vibrators sticky, but a bit of tapping and use got them
>>> working again. I think I was lucky there.
>>> 
>>> Intermittent squelch in RT-70. Found a number of leaky paper
>>> or film type caps in audio section, replacing made squelch a little
>>> less flaky. As I remember there were two different
>>> types that looked the same, but one was
>>> physically larger than the other. The large ones were
>>> good, the small ones were all leaky.
>>> 
>>> Finally found that the tip of the tip of the last
>>> limiter had broken off, was hard to see visually.
>>> I think that particular tube was a bit taller than
>>> the normal size, and it had broken off when the radio
>>> was pulled out of the case.
>>> 
>>> Strange thing is that the receiver still functioned,
>>> although volume was down and squelch just didn't
>>> work right.
>>> 
>>> Last problem is that the 1Mc calibration crystal was
>>> missing, I replaced it with another from the "box du junque",
>>> it sort of works, but the cal signal is weak.
>>> 
>>> Hope this helps you get your set running.
>>> 
>>> 
>>> 
>>> Jack Antonio WA7DIA/4
>>> 
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