[Elecraft] Remote Antenna Tuner

[Don Wilhelm]

While it may be true that the tuner does not NEED to be at the antenna, if I
would feed to my 30 meter EDZ antenna direct with 50 ohm coax, the SWR on
the line will be in excess of 20:1.  I am not willing to accept the >5 dB
loss that I will have with RG-213.  Actually I do feed that antenna with a
15.1 foot length of 450 ohm ladder line, use a 1:1 balun at that point and
feed to the shack with 50 ohm RG-213 - it works fine, but it is a singleband
antenna for 30 meters.

If I had a remote balanced tuner, I could multiband it by feeding with 55
feet of the ladder line to the tuner, and then use the 150 feet of coax to
reach the shack.  My coax run is all inside - either in conduit (65 feet)or
inside the attic space of my workshop/garage (85 feet), and it is just not
practical to run parallel line for those parts of the feedline run with all
the twists and turns.  I have agreed with the XYL that the feedlines could
be kept out of sight from the house, so this is the consequence of that
decision.

Actually, I am expanding the antenna farm, and with my current plans, I
really will not need the remote tuner.  I will have dedicated antennas for
each band, and can use fixed tuning units anywhere it is convenient to place
them - and I do have good parts for the old fashioned link coupled parallel
tank circuit tuners, but if Elecraft offered something like a remote version
of the KAT100 and make it usable for balanced line by adding additional
relay points and inductors in the 'other' side of the line, I would buy one
just to have one multiband antenna available.  I think I could modify the
existing KAT100 for balanced output easy enough, but the AUXBUS timing issue
is a mystery for now.

73,
Don W3FPR

----- Original Message ----- 

| this discussion is handled extremely well in a book by M. Walter Maxwell,
| w2du called reflections II and is available from world radio book store.
He
| makes the argument and does the math that the tuner does not need to be
| remote.
|