Dave Abshire Sr. - KG4KOX
ICOM's IC-706MKII transceiver and AT-180
antenna tuner are designed to work together. However, ICOM's
AT-160 is a very popular antenna tuner. Originally designed to
work with the IC-728 and IC-729 transceivers (now out of
production), the AT-160 will work with the IC-706MKII if the
following instructions are followed:
- (IC-706MKII only, not IC-706) The
IC-706MKII will transmit on VHF constantly when connected to the
AT-160. To stop this, remove the wire attached to pin 6 of the
DIN connector within the OPC-104 cable.
- Open the AT-160 and make sure the
switch labelled "S1" on the circuit board is switched to the
bottom, shown as "IC-725/726" in the AT-160 instructions.
- Make sure that the connections to the
AT-160, using the OPC-319, OPC-104, or OPC-125C cables, are
according to the AT-160 instruction manual. ICOM America
suggests using the OPC-599 adapter cable for connection of the
OPC-104 to the IC-706MKII.
- Connect the radio to the transmitter
terminal and connect an antenna to the ANT terminal. Make sure
the antenna has less than a 3:1 SWR. Place the radio in FM, AM
or RTTY mode and key the mic. The AT-160 will now tune properly.
- The tuning button on the front of the
IC-706MKII will not operate when using the AT-160 antenna tuner.
This feature was designed to work with the AT-180.
- Check the SWR presented to the radio.
It should be less than 1.5:1. The AT-160 operates with the
IC-706MKII as it would with the IC-725 or 726 transceivers.
Included with the AT-160 instructions is a page dedicated to the
antenna tuner's operation with an IC-725 and IC-726 transceiver.
This is not the way the AT-160 operates with the IC-706MKII.
- There is no way to turn the AT-160 off
or place it into "thru" mode when operating with the IC-706MKII.
|Subject: Extra note
I cut one end off the OPC-104 that came
with the AT-160 and used the small 13 pin adaptor that came
with the 706 MKII. NOW you must leave pin 6 un-connected or
your radio will stay keyed on 2 meters.
I did the mod and it works great on
HF but I can't get it to tune proper on 6 meters, It will tune
to a 1:1 then next time you key up it will retune again. If
anyone knows a way around this please let me know.