K6KR:
< EHS is a lot cheaper than Phillystran. How much of the 75' guy should be
Phillystran for 'good' HF results? The antennas are the tower are on 40,
20, and 15 meters, and the booms are about 48' long on 15 and 20. Can I
expect 'good' results with, for example, 35' of Phillystran and 40' of EHS?
How would I figure this out?
Here are two simple rules to follow for EHS lengths:
1. Avoid open 1/2 wavelengths or multiples for on any band you intend to use.
2. Avoid grounded 1/4 wavelengths or multiples for any band (i.e. the
grounded end).
There once were suggested lengths in the ARRL Antenna Book to avoid
1/2 wave resonances (not sure if that's in the latest versions). I
recall that 39.5' was one of the magic lengths. You need to Grid Dip
the EHS to check for actual resonance since any loops around
insulators will have a loading effect and shift the resonance.
Practically speaking, you can probably forget rule #2 above. Your
guess above is very close.
73, Bill
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