[Elecraft] Icom Remote Antenna Tuner

[Jim Allen]

> I am looking at remote antenna tuners. I have seen several controllers for the ICOM AH-4 tuner. My questions are about operation with a K3s.
> 1.	Is there a limit to the time that 10w of RF can be sent to the AH-4 via the K3s Tune button?
> 2.	All circuits specify a momentary switch, but does momentary mean 0.1sec, 1.0sec or 5seconds? Does the time matter?
> 3.	When the complete signal returns from the AH-4 should the Tune RF or the momentary be terminated immediately?
> 4.	Is there a combination of momentary or Tune RF that will damage the AH-4?
> I have an AH-4 which worked with a home built controller for some months, and then became operationally intermittent and final fails to work at all. That makes me gun-shy, about buying another even though the AH-4 gets excellent reviews on eHam, almost all of which are based on an ICOM rig control.
I have used an AH-4 for many years, with a 706MKIIG and with various other manufacturer's radios, including now a K2.  Other than the limitation to ~125 watts, these are excellent.  I only run 5 watts so it is not an issue.  I do not recall a situation where the AH-4 would not give a useable match, provided I provided it a plausible antenna.  I use a separate SWR/watt meter that shows it working.

The momentary switch  is push on, release off, no time specified.  Pushing the button signals the AH-4 to run through its paces for a match.  Most often, it is very quick.  Occasionally, when you have gone from, say, 15M to 80M, it might take a little longer, but never more than several seconds.  If no match can be found, it just stops.  Either way, you stop the power. I wouldn't let it just run like that, but have never heard of damage because of it.  You need to reduce power with non-Icom rigs that don't do it automatically.

You might join the Icom tuner Yahoo group, if you can stand Yahoo.  Lots of user experience there.

I've never seen a store bought controller for the AH-4.  Where have you seen them?
73 Jim Allen W6OGC 

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