Topband: ICOM-706MKII and receiving antennas

[K4SB]

Ted, will let you know what I did with a TS940, and a 850, and
plan to do with my 706.

You have an unused AUX plug. I merely mounted another AUX plug on
the rear close to where the TX/RX relay is. Now, remove the RX
cable from the relay, and connect it to the center of one of the
AUX plugs. Similarly, using small coax, connect the other AUX
plug to the relay where you removed the coax.

Now, first things first, if you jumper the two aux plugs, you're
back in business just like you were before. Howsomever, if you
connect the aux plug with the original relay coax to a Selectable
TV switching box (A/B box ) ( let's say just a 2 position box
right now )  common, then bring your RX antenna to "A" and jumper
"B" back to the other AUX plug. Now connect your RX only antenna
to "A"

In "B" the radio is the same as before, but if you switch to "A",
ONLY the RX antenna will be connected.

1. It is absolutely impossible to transmit on the RX antenna.
2. I think the A/B boxes now come with up to 4 or 6 selectable
positions, which allows you to feed in more RX only antennas. But
if not, all you have to do is use another A/B box beside the
first one.

It's simple, takes about 10 mins to make the mod, and the mod can
be permanently removed by just putting the RX coax back where it
was. You do end up with the extra AUX plus.

And on those occasions where you don't want to use it, such as
mobile, ect. Just jumper the 2 Aux plugs.

73
Ed



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