[Antennas] MODIFYING_TRIBANDER_BEAM

[George]

Since I Santa did not bring my new SteppIR three element beam I'm forced to
modify my Wilson S-33, like the Mosley TA-33.
I would like to re-wind the traps to put the beam on 20, 17, and 15 or 12
meters.
I noticed that the longest element is not long enough to affect a dipole on
20 meters.
My questions to the antenna engineers out there are:
Since the elements are not long enough for a dipole on 20 meters does the
traps add some loading on 20 so as to allow a shortened 20 meter element? Do
they also allow for a shortened 15 meter section as measured between the two
traps on an element?
Is there any formula to estimate where the traps should be placed out on the
elements when wound for 17 and 12 or 15?
I can't see any problem re-winding the traps at will for any frequency I
want between 17 and 10 meters. I probably won't be much of a problem getting
aluminum to extend the elements which I figure should needs to be done in
order to re-do for 17 meters.
I purchased the ARRL antenna book and tri-banders and traps are not covered
to any extent to allow one to build their own.
In order of importance for my operating interests the bands are 20, 17, 12,
15, and lastly, 10 meters.
I would ultimately re-do my tri-bander for 20, 17, and 12 meters with 15 as
a substitute for 12 meters if I cannot have 12 meters. I have all winter up
here near Buffalo, NY!
I must thank everyone on the reflector for helping me in the past.
Thanks.
George  W2YJ@HIGHSTREAM.NET