[Elecraft] Interface question.

[Phil & Debbie Salas]

As you've stated, so far the K3 doesn't have an external TUNE-KEY input. 
This will have to be provided when the KAT500 is available - probably the 
AUXBUS interface.  I have used a MFJ-998 with my K3 and ALS-600 for a couple 
of years now - and now a KPA500.  I leave the MFJ-998 in the full-auto mode 
and use the K3 TUNE function (TUNE power set for 15 watts) when I need the 
tuner.  No problems at all.  The MFJ-998 interrupts the amp-key line before 
it tunes.  I've recently modified my MFJ-998 so it uses the amp-disable 
feature of the KPA500 (info on my website) which is a much better way of 
taking the KPA500 off-line prior to tuning.

I WILL go with the KAT500 when it is available though.  I'm sure it will 
integrate superbly with the K3 - just like the KPA500 does.

Phil - AD5X

"I have an MFJ-998. I wish I'd known better when I bought it - I
wouldn't buy another (for various reasons). I never found a good way
to integrate it with the K3... so the tune-up procedure involves using
the K3's "TUNE" function to produce a low-power signal (CONFIG:TUNE
PWR) and then invoking the "TUNE" function on the MFJ (it's configured
in "Semi-Automatic" mode). When the MFJ finds a match (or doesn't), I
tap "XMIT" on the K3 to end the "TUNE". There is a fully-automatic
mode, where the MFJ will initiate tuning when it detects SWR above a
configured threshold, but I had bad experiences with that in the past.

If the K3 had a way to feed a signal into the ACC connector to trigger
the TUNE function, the MFJ could utilise that. The suggestion has been
made a few times, but it's probably not a high enough priority on
"Wayne's list".

Aside from the KAT-500, it appears (from their website) that PalStar
are working on a new remote-able autotuner rated for 2500W. I'm sure
it'll cost a lot more than the MFJ, but... you know what they say ;)

73,

    ~iain / N6ML"