JN wrote:
- Adding center extenders could help but then 75m hamsticks are out of 80m
band ... Any comments on these?

This is not necessarily true. Since the length of
the top stinger has a much greater effect on resonant
frequency than the length of the bottom section, you
can increase that bottom section length by a large
amount and then adjust the top stinger length by a
smaller amount to achieve the desired resonant
frequency. And you are going down in frequency to
the CW portion of 80m.

For instance, you might extend the bottom portion
by 6 feet and only have to shorten the top stinger
by 2 feet. (When you shorten the stinger, you may
have to hacksaw off a portion to keep the stinger
bottom from residing in the middle of the loading
coil.)

Let's say you have an eight foot long base-loaded
mobile antenna. You decide to move the loading coil
farther up the antenna to the center-loaded position.
If you keep the *same length and same coil*, the resonant
frequency will increase. You have to add more stinger
length to bring it back to the original resonant
frequency (or more coil). Moving the fixed coil farther
away from the feedpoint requires the antenna length to
be increased. That fact works in your favor.

Since the additional bottom section is moving the
fixed loading coil farther away from the feedpoint,
the above effect will occur for your extended
configuration. Experiment with it and see what
happens. You could just use wire for the
experimentation and hang it between two supports.

-----/////-----+-----FP-----+-----/////-----
hamstick wire wire hamstick

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73, Cecil http://www.w5dxp.com