Author: AA7OL Niko
Icom AH-4 and AH-3 ( automatic antenna
tuner ) connection to any radio
Both AH-3 and AH-4 are similar
Here is a redesign of connection digram of
the ICOM IC-AH3 and IC-AH4 by 5B4AEZ.
There is four wire control cable coming
out beside coax cable.
Control cable has
- Put about 10 watts of power into
tuner. ( CW )
- After about 0.5 second, press start
switch for a moment. ( use momentary contact switch )
- LED start blinking , which indicate
tuning is in process.
- After about 3 seconds or so, LED shut
off, and tuning is completed,
If tuning is successful SWR should be
less than 1.2
Some radio start to reduce the power when
SWR is high, this tuner takes at least 10 watts of power for tuner
to work properly. Most of the 100 watts radio should not have any
problem, since they still put out 10 watts or so, even with high
But, it does not work with some QRP radio
( 5 watts or less ).
Adjust power level, if necessary.
You may extend control cable to 100 feet
, it still work fine, you can put this tuner on top of tower.
Let me know , how it worked