In regard to possible BC station interference as outlined below, the BC
signal can generate a 2nd harmonic in the receiver. Hi-pass filters that
allow passage of frequencies above say 1.7 MHz block the fundamental and
solve the problem. I'm told this would clean up the measurement for the test
equipment. Also try a single series resonant circuit with a BC variable and
inductor for the BC band signal and observe the affect at 1.8 MHz. Jokey the
L/C ratios. k7gco
In a message dated 9/30/01 9:06:44 AM Pacific Daylight Time, firstname.lastname@example.org
The trick I use is to make my 75 ohm feedlines a
multiple of 1/2 WL. Of course on 160M that can
result in inconvenient lengths.
Another trick is to match the antenna to 75 ohms.
Then you have NO SWR on the CATV feedline and 75 ohms
at the transmitter regardless of the feedline length.
75 ohms results in a 1.5:1 SWR for a 50 ohm system and
is pretty easy to match for most radios / amplifiers.
In a message dated 9/30/01 8:27:48 AM Pacific Daylight Time, SavageBR@aol.com
If you think you have a BC station problem, you might try the same
measurement late at night if your suspect station is far enough away to
change field strength with skip.
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