Yes, choke baluns really work.
I just finished assembling my C-3E, including the choke balun. It takes many
feet of coax to make the pigtail for this antenna when you account for the
balun (I chose 8 turns at 7.5" OD), and a multiple turn compliance coil for
rotation (3 turns at 12" OD). Those two coils alone add up to about 25 feet.
Add to that the desired runs along the boom and mast.....and I used about
30-35 feet of coax.
I chose RG-213 with solid dielectric to prevent the center conductor from
migrating over time, which can be a problem in the heat of summer with the
foam dielectric types formed into such a curve.
I wound my balun on a gallon paint can with 8 turns. Don't wind too tight or
you won't be able to slip it off the crimped can edges! Surprise! ha ha ha
I plan to pull the beam partway up in the air first, on a non-metallic tram
line, and connect my analyzer to the pigtail to check the SWR curves before
'popping' the rivets in the 15 and 10m adjustable elements. I'm holding the
adjustable segments in place with a single, un-popped rivet, held in turn,
by a short piece of tape impaled over the rivet's mandrell.
During assembly of the antenna elements, I discovered one possible source of
trouble: If the rivets holes do not line up *EXACTLY*, stop and flip that or
the adjoining piece of tubing end-for-end and look again. As confirmed by
Tom at Force 12, some of the pieces get flipped during packing. There is
only one orientation where all rivet holes line up exactly. I checked the
orientation of all pieces in each element before popping the first rivet.
Also, faint swage marks appear on some segments. These always pointed away
from the boom, and served as an additional clue to flipped segments.
Good luck Barry,
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