[R-390] [Milsurplus] [Boatanchors] CU-872A/U antenna coupler FS near Boston

[Roy Morgan]

> On Feb 20, 2019, at 7:08 PM, Francesco Ledda <frledda at att.net> wrote:
> 
> Also, the CU-1099/FRR is 70 ohm. It was used with receivers with Z 50 ohm.  Wonder why….

I am guessing:  a system of 70 ohm coax connections might have lower loss than the more common 50 ohm coax.

The TMC transmitters like the GPT-750 operated with 70 ohm outputs, and I remember right, interconnections among RF portions of transmitting systems were also 70 ohms.  (Many of their transmitters operated with inputs from oscillators or multimode RF generators at the level of 200 milliwatts.)

Roy

Roy Morgan
K1LKY since 1958
k1lky68 at gmail.com