[Elecraft] Re: Max distance KAT100 - K2?

[Wayne Burdick]

Hi Pete,

We have only tested the KAT100 in the lab with 5' and shorter control cables,
which work fine. However, we recommend using the shortest possible length (1 to
3') because the cable can pick up RF, which may make power and SWR readings
unstable. The KAT100 is not really intended to be a remote tuner, as you can see
from all of those useful LEDs, but it should work this way. Don't leave it
outside, though, as it's not environmentally sealed.

If you want to use a longer cable, there are a few things to keep in mind:

1. Doing auto-tunes at QRP levels is strongly advised (POWER control set for 10W
or less, or KPA100 turned off).

2. If you're using a KPA100 in your K2, and you do find that power readings are
unstable with the long KAT100 control cable, you can disconnect the "VRFDET"
wire at both ends of the control cable. This is because the KPA100 itself
provides the VRFDET signal to the K2, not the KAT100. If you have no KPA100,
though, you'll have to keep the VRFDET line connected, since the KAT100 supplies
the VRFDET signal in this case. But of course power levels are much lower
without the KAT100, and chances are there would be no RFI problem.

3. If you try both of the above and still have problems with RF getting into the
cable, you may have to substitute a more heavily-shielded type of multiconductor cable.

Please let us know the results of your experiments. If a number of KAT100
builders successfully remote the tuner, we can add a note about this to the
KAT100 manual. (In fact if you want to experiment with a much longer control
cable, feel free. If you're going over about 10' I'd recommend the use of a
high-quality RF cable, too.)

73,
Wayne
N6KR



Peter Halpin wrote:
> 
> Hi all,
> 
> I've crawled through the builder's resources page but I can't find an answer
> to a simple question: what is the MAXIMUM possible separation between a K2
> and the KAT100 (it hasn't arrived yet 'cos it's being held at customs -
> grrr) ?  Has anybody tried something like 25' or more? I'd like to be able
> to put the KAT100 at the rear of the house and use just a foot or so of coax
> to link it to a current balun for use with open line.
> 
> 145, Pete  PE1MHO - G7ECN - M3ECN  K2 #2768