>I have a 250' long RG8X cable that was used to return the "dumped" power
>from my 80M 4sq to a power meter and dummy load at the operating position.
I don't know why you got funny measurements, but I can suggest a way to
eliminate that extra cable altogether. I put the dummy load and directional
coupler for the dumped power meter with the switch box at the center of my
40M 4-square (under the traditional plastic trash can.) 360' of 6-conductor
rotor cable runs between the shack and 4-square: 3 conductors for the switch
box and 3 conductors for the DC signal from the directional coupler to the
power meter. Even with 22-gauge conductors, the voltage drop is miniscule
and does not significantly affect the meter reading (I tested it before
installation with 500 feet of phone wire.)
There are probably a number of inexpensive SWR/power meters with directional
couplers that can be mounted remotely, although you might have to do a
little surgery to disconnect the wires at one end. Or, you could build one
yourself (I know of one Tower Talkian who did that.) I used a digital
SWR/power meter from Radio Shack that was specifically designed for the
coupler to be mounted remotely at the antenna. It's been discontinued, so I
only paid $50 for it. It's such a nice meter (small, backlit, peak/average,
up to 2000w), that I wish I'd bought two or three! It's been about a year
since I got mine, but you still might be able to locate one through your
local Radio Shack store. Have them check with the distribution center in
Texas. That's how I got mine. The catalog number is 21-527.
Eliminating the cable is the best way I know to avoid contamination (and
critters chewing on it.) Also, if your run is very long, you don't have to
subtract the cable loss from the dumped power reading.
73, Dick, WC1M
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