FS : Nice IC-451A 440 Mhz. transceiver.Here is a rundown: Unit is in nice
condition and has Icom desk mic.On the rear panel , in one of the "spares"
holes, a phono connector is mounted.A transistor switch circuit is built on
terminals of phono socket { inside radio}that will key an external relay.I
used a heavy TO-39 transistor and was switching a 28 VDC control relay in
external amplifier.
Also, the receiver input cable ,from internal PIN diode switch, is
interrupted and brought to rear panel pair of BNC jacks { both mounted in
other 2 "spares" holes}.If you desire to use an external preamp you can
place it inline here, and not have to RF switch it if it does not bother you
using internal PIN diode TR switch.Or, you can just bridge these BNC jacks
to use radio as-is.Another option { the one I was using}is to use an
external RF relay and go straight into receiver with external preamp.
Anyway, this is a nice radio with 2 desirable additions.It is in
original box with manuals. Price is 325.00 plus shipping.Thank you,WA5THJ.