Aloha to those still interested in this topic!
And again, thank you for your many inputs and responses.
Have considered them all, and now the following will be
done, I hope:
Use of accurate attenuator:
Several of you suggested I look at the switchable attenuator project
in the ARRL Handbook. I have, and am sure I have not the patience
nor the willingess to hand select all the needed accurately measured
resistors to assemble such a unit; so I will buy something!
I have not been able to find a switchable, known increment attenuator,
Nebraska Surplus has sold out the only suitable unit they have in the
catalog. However, I was able to order from them a series of small
(SMA connectors) "precision" attenuators, have ordered a couple each
1 and 2 dB units, and one each 3, 5, and 6 dB units, along with SMA
to N connector adapters. Won't be quite as handy as switch selectable
attenuation, but at least should be provide more accuracy than my
Other problem will be finding signals with a reasonably constant
amplitude over a period of time. Perhaps the W1AW signal, for
example. With these attenuators, I won't have
to depend upon known amplitude changes from the source.
I now must get busy and set up a measurement/test regime;
whatever the result, it should be interesting. On 40 m, I can
compare to my inverted-V, and for the TL80 and TL160, to my 1200
foot long, center fed doublet!! Not sure will be of
any real value, as the wires are too low, and certainly "lobed"
(if that is a word, hi).
I will take data at night also, when the DX signals are coming
in at low angles; at 10 AM out here (2000 UTC), am sure the
angles are pretty high, thus favoring low beams and dipoles.
Will also be taking data over periods of months.
More info and data after I get set up and going again.
73, Jim, KH7M
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