[Elecraft] KATxxx Remote Tuner

Jim Brown jim at audiosystemsgroup.com
Sun Apr 19 13:41:43 EDT 2020


On 4/19/2020 8:51 AM, ab2tc wrote:
> I totally agree with your last statement about the tuner placement.

The importance of a tuner being at the feedpoint depends entirely on the 
antenna, the frequency(ies), and the feedline. The lower the operating 
frequency, and lower the feedline loss characteristics, and the lower 
the mismatch, a tuner in the shack can work quite well at moderate power 
levels. AD5X, who does product reviews for ARRL, reviewed the "43 ft 
vertical," which is notoriously difficult to match. One solution he 
found was a 4:1 unun at the feedpoint and 1/2-in hardline to the shack. 
For high power on 160 and 80M, he used a tuner at the feedpoint.

Some years ago, I successfully loaded a vertical on 80M that was 
resonant on 160M, hence a VERY high impedance at the feedpoint. The 
feedline was RG8 and only about 40 ft long, so I was able to load it 
quite successfully with a Ten Tec 238 tuner in the shack and a legal 
limit Ten Tec tube amp.

On 60M, I'm currently loading a high 80M dipole fed with 160 ft of RG11 
using the tuner in the KPA1500. The amp, of course, is throttled back to 
less than 100W. I'm not the loudest signal on the band, but I've worked 
into EU and SA in a few evenings on the band.

73, Jim K9YC


More information about the Elecraft mailing list