[MRCA] AN/PRC-77 RELEY, RETRANSMITT

Fri Oct 1 10:39:58 EDT 2021

Zorro,

I'd forgotten that I had one of those.

Thanks,
Al

On 9/30/2021 9:50 PM, B. Smith wrote:
> And if you want to play with a 30 to 76 Mc diplexer. However when 
> using some of the modern radios such as the PRC-64 you have to add a 
> internal resistor to provide the DC load at the antenna port.
> Z
>
>
>
> On 9/30/2021 8:43 AM, Gary Decker via MRCA wrote:
>> I looked up a cable for the PRC/77 re-trans and they want a $109 for 
>> it plus 60+  $'s shipping from Poland.
>> It would be interesting to setup the British radios to do this. I 
>> have a bunch of them to bring if needed. Yes, Walt seem like a 
>> simpler set-up being that you do not need that expensive cable. Would 
>> like to see it in action. Always liked the idea of setting up a 
>> portable repeater.
>> Gene, I did read about the PR 25/77 used to link to helicopters using 
>> re-trans to communicate up to distance of 100 miles. Not sure how the 
>> Helo config looked since you don't have the antenna separation, 
>> unless it was done between two helo's.
>>
>> On Wednesday, September 29, 2021, 11:16:24 PM EDT, Walter J Skavinsky 
>> <walter.skavinsky at comcast.net> wrote:
>>
>>
>> It seems  retrans on the British radios is a simpler process.  There 
>> is no requirement for specialized connector cables.  The wireline 
>> connection on the side is used.  D10 wire (aka is wd1) is used to 
>> connect the radios.  Min Distance is not mentioned in the manual 
>> however this requires the use of the surf unit on the radio.  Surf is 
>> the “selective unit radio frequency”.  It’s basically an input 
>> filter.  This allows the radio to operate in close proximity to other 
>> radios on the same bands.  It is possible to operate with his little 
>> as 2 MHz separation And requires both units to have properly tune 
>> surf which can be done in the field.
>>
>> The radios can even be separated in a retransmit station as far as 3 
>> km via wireline so it’s possible that radios from two Forward 
>> operating bases that are connected via wireline can be used in a 
>> re-transmit operation.  But the co-locating abilities of the 351 is 
>> superior to the PRC 77 in its simplicity.
>>
>> Several years ago I want to say around 2014-ish maybe earlier we set 
>> up a re-trans station in the picnic Grove up from the fire company 
>> and were able to re-broadcast back to Gilbert.  That day we were 
>> actually using both PRC 351 and we even did a cross band re-trans 
>> using the PRC 344 on 2:20 AM
>>
>> I have gained a healthy appreciation for the design and simplicity of 
>> the British radios
>>
>>
>>
>> 73
>>
>> Walt
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> > On Sep 29, 2021, at 22:49, Gene Smar via MRCA <mrca at mailman.qth.net 
>> <mailto:mrca at mailman.qth.net>> wrote:
>> >
>> > Thanks, Gary.
>> >
>> > It would be fun to try this ourselves but we'd need to find a way 
>> to transmit within the 6M amateur band exclusively.ï¿½ TM 
>> 11-5820-667-12 for the PRC-77, p 6-1, states that Cable Assembly, 
>> Special Purpose, Electrical CX-4656/GRC is needed to interconnect the 
>> two -77s.ï¿½ It also states that the two freqs must be at least 3 Mc 
>> apart.ï¿½ We'd have to check for interference between our selected 
>> freqs by checking the freq compatibility table also in the TM 
>> above.ï¿½ Lots of spurs possible with synthesized radios, I guess.
>> >
>> > I read somewhere, and include this bit of info in my PPT 
>> presentation on squad radios, that this relay arrangement was used in 
>> Vietnam to enhance comms between troops on the battlefields and 
>> artillery batteries miles away.ï¿½ The relay, I had read, was inside 
>> a fixed-wing aircraft orbiting at some low altitude between the 
>> battlefield and the artillery.ï¿½ Can anyone confirm this from his 
>> own experience?
>> >
>> >
>> > 73 de
>> > Gene Smarï¿½ AD3F
>> >
>> ______________________________________________________________
>> MRCA mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/mrca 
>> <http://mailman.qth.net/mailman/listinfo/mrca>
>> Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm>
>> Post: mailto:MRCA at mailman.qth.net <mailto:MRCA at mailman.qth.net>
>>
>> This list hosted by: http://www.qsl.net <http://www.qsl.net>
>> Please help support this email list: http://www.qsl.net/donate.html 
>> <http://www.qsl.net/donate.html>
>>
>> ______________________________________________________________
>> 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
>
>
> ______________________________________________________________
> 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

-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20211001/a0ebf5a1/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: kfnmhmiidgcfnnba.gif
Type: image/gif
Size: 9511 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20211001/a0ebf5a1/attachment-0001.gif>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: fhkcnppbbalnnlfp.jpg
Type: image/jpeg
Size: 90411 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20211001/a0ebf5a1/attachment-0001.jpg>