Tom, W8JI wrote:
"This is a very good point! Earl, how do you know the increase in third
harmonic 'copy' is not actually from rig defects??"
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If there is actually no 3rd harmonic being radiated by the BC station, I
assume that you're saying that the fundamental (at 610 kHz) is causing
the receivers under test to somehow generate a pseudo-3rd harmonic.
The fundamental is so far removed from the tuned frequency of my array
that I doubt that the fundamental is causing anything detrimental.
Additionally, when I use my MFJ-259 (or Autek VA-1) to periodically tweak
the shunt feeds on my towers there is no upward swing of the MFJ's meters
that some experience in the presence of strong BC signals.
When I tune my MP to 610.00 kHz while receiving on the 160m array, the
S-meter reads S8-1/2 with the IPO off and S7-/1/2 with the IPO on --
hardly an overwhelmingly strong fundamental at the receiver's antenna
input.
As far as I am concerned, there is an actual signal at 1830 kHz which is
steady and is therefore handy for the A/B tests. It is heard on every
radio I have A/B'd.
On 10-meters, the test signal is WA6APQ/BCN, an amateur beacon station in
Long Beach which is also a steady ground wave signal here whose
fundamental is used (not 3rd harmonic) at 28243.9 kHz.
73, de Earl, K6SE
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