Re: Seen these Auto ATU's


By the way with an 8:1 SWr using RG8X at 7 mhz the losses would be 2.24dB or about 40%%.
100 watts in 53 watts at the antenna.
About 34% at 4 mhz, and 50% at 14 mhz, 60% at 28 mhz.
By the way I could measure this and the losses occur on receive as well.
Best not to give up that much when already handicapped in emergency and portable operations.
For that matter losses are losses at home as well.
A tuner at the antenna is more efficient in many ways due to mismatched currents in the shield as well with noise pickup etc.

On Mon, May 25, 2020 at 10:42 AM J.D. Barron via <> wrote:
You are correct, but if you need the tuner anyway might as well put it where it will do the most good, especially if it is small and low power. In the camper I use for my emergency go box there is not a lot of excess space anyway,
I know that with the AS2259 the mast is actually a very low loss foam filled coaxial feedline that plugs together to get the height. This low loss mast plugs directly into the tuner in this case.

On Mon, May 25, 2020 at 10:24 AM Helmut Wabnig <hwabnig@...> wrote:

Have you ever measured "feed losses"?

This is like something from hell or evil devils.

In normal circumstances, that is, not extremely off VSWR,
the so called "feed losses" cannot even be measured with standard
cheap amateur radio equipment, so small they are.

If you have not tried it, you don't know.


J.D. Barron

J.D. Barron

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