[MRCA] Collins 718U-1

[W2HX]

Hello friends,

I acquired a very unusual manpack transceiver. It is a Collins 718U-1 and here are some picture:
http://w2hx.com/x/Collins/718U-1/

According to what I've read, it is a 100W radio (interesting) that uses a PRC-47 battery/battery box.  It consist of two components.

*        671U-1 Receiver-Exciter

*        548S-1 Power Amplifier Coupler

There is very little information available on the internet for this radio. But what I have found is that there was a series of radios used in aircraft that were some how similar to these components.

https://tsc-60.cellmail.com/tsc-60/other/174/index.html

718U-1/9:

Consists of 671U-1A and 548S-1 PA coupler (100 watt).

*        U-1 version was a "manpack" config uses a PRC-47 antenna and BB-451/U battery.

*        U-9 is Transportable/Vehicular/Base system with 990X-2 mount and 981G-1 load coil. Uses AT-1011 antenna.

*        The 671U-1A is a panel mount radio. The synthesizer boards are similar to the 671U-4, but the others are somewhat different.

*        Marine AN/TRC-169. Local guy had a 671U-1A working, but couldn't talk him out of it.

What is also interesting is that there is some documentation that another Collins system, the AN/PRC-515, could be used with a 100W PA/coupler

>From information on the internet on the PRC-515 (RT-5047/URC) from WB4TUR/KB0SFP:
"Known options, variations, & accessories include 549A-2 20 watt backpack PA/coupler, 548S-1 100 watt station PA & coupler, 541C-1 150 watt man-pack, vehicular, or fixed station PA/coupler, 548T-1 400 watt PA, 490T-2A coupler (400 watt station), 718U-5 100 watt portable PA. 671V-6 receiver-exciter unit, updates existing PRC-515 & GRC-220 equipments for split-frequency operation, with the addition of dual frequency controls."

It is also interesting that the PRC-515 receiver exciter carries the collins original designation of 671V-2 (whereas this receiver exciter is 671U-1)  You will also note the description above referencing a 548S-1 (100 Watt station PA & Coupler) in the description above. This is the same PA/coupler used in this 718U-1.  Has anyone seen of a RT-5047 (671V-2) paired with a 548S-1 for a 100W station (prc-515 with 100W)?

I am looking for documentation on the coupler, specifically Collins 548S-1 (Collins Part No. 787-6576-001) might anyone have such a thing stashed away? Might the CCA have any documentation for this? I have found documentation on the S-3, 3A, 5, 5A and 6 (aircraft stuff) but nothing on the S-1 and I don't know how similar/different they are.

Any and all comments/histories/knowledge/speculation/spare parts welcome
Thanks!


73 Eugene W2HX


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