Ford,
Questions and comments.
Q: I like the rf probe idea...and I think I can draw the circuit
you created...but rather than speculate, can you either send me
something directly...or post here if easier... showing the 9 turn
windings and how you oriented and connected them to the bridge?
I'm assuming the coils are in series, and connected across 2 terminals,
with the meter across the opposing pair, bypassed with the cap.
The coils need to be wound in the same direction, correct? What
ferrite did you use?
Comments:
1) I'm a fan of elevated GP's, whether folded in an ell or not.
I have tended to use 3 radials @ 120' spacing as well. W1CX
convinced me that having 4 radials...two opposing pairs...would
produce a cleaner pattern, and less high-angle radiation. FWIW.
2)I can only speculate that your north radial is over earth which
is different from the other two, and that's the source of the imbalance.
3) As a practical matter, I have made several monobanders for 160, 80 and
40,
and one 160-80 dualbander, most with 3 radials per band. In all cases,
I cut the vertical portion for the low end of the band, and cut radials
at 105%. Then, I fold back the radials equally to bring vswr to target.
I just wrap them around themselves 2 to 3', and usually don't cut them.
This doesn't assure a balanced pattern, by any means, and I may explore
your approach at my new site, this winter. Available trees lend themselves
to GP's.
Tnx.
N2EA
jimjarvis@ieee.org
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