[R-390] Multicouplers - active vs. passive

[Nick England]

FWIW, the CU-872/URR is an R-390 era multicoupler with what I guess is
a similar design to Don's  -
http://www.navy-radio.com/rcvrs/coupler/cu872.htm
These were used in some versions of the AN/FRD-10 Wullenweber
(elephant cage) system.
More Navy multicouplers are listed at
http://www.navy-radio.com/rcvr-coupler.htm
cheers,
Nick K4NYW
www.navy-radio.com

On Tue, Jan 15, 2013 at 8:36 PM, 2002tii <bmw2002tii at nerdshack.com> wrote:

> If you build an RF amplifier like the one in a TenTec RX340 (not the
> switchable BFG16A RF preamp, the RF amp comprising six J310 FETs in
> push-pull parallel) [schematics are available on the web], you will get 6 dB
> of gain with input-referred noise approaching -130 dBm in a 3 kHz bandwidth,
> harmonics around -80 dBc at 100 mV input (-7 dBm), and enough headroom to
> shrug off nearly anything that doesn't melt your antenna.  Run with a 12 V
> supply, the 1 dB compression point is greater than 4 Vrms input (+25 dBm).
> Follow this amplifier with a passive splitter, and you will have a
> state-of-the-art multicoupler.  System gain will be ~ +3 dB with a 2-way
> splitter, 0 dB with a 4-way, and -3 dB with an 8-way.
>
> Copyright (c) 2013.  Not for redistribution
>