I am putting up my old TA-33SR by Mosley. I need to know how many windings
are needed on the choke. I seem to remember 6" diameter, but not the
amount of windings.

According to the manual there is no choke indicated at all.

Anyone know anything about this?

Dan/W4NTI

===================================
Dan, I am unable to help you.

Because, in common with most other people, I havn't the foggiest idea
what a TA-33SR is.

Questioners would do better by not depending on other people's
imagination. It takes only a few seconds to provide a little more
essential information. If you can't find the time then it can't matter
very much anyway.

Reg, even to me (a relative newbie) "Mosley TA-33SR" provides all of
the information needed to identify what Dan is talking about. A very
brief Google identifies as a triband trap beam. I have little doubt
that anyone who has ever owned one (and is thus likely to have the
direct information that Dan is looking for) would recognize it from
his description with no further description being required.

Dan - since Mosely's manual doesn't mention such a choke, and the
instruction sheet indicates a direct attachment of the coax to the
driven-element feedpoint terminals, I doubt that the details of the
choke are terribly critical. You could probably use any of the plans
on the net for an air-wound coaxial choke-balun. One plan I see uses
18-21 feet of coax, close-wound solenoid-style on a 5" PVC form
(stated to be good for 160-10 meters).

Another site (http://www.bcdxc.org/balun_information.htm#Ed,%20WA2SRQ)
has a table of air-core balun impedances, as a function of both
frequency and construction (turn count and diameter). This chart
suggests to me that 4 turns, 6 5/8" solenoid-wound might be a good
option for you, as its impedance peaks at around the 15-meter band and
is 500 ohms or better between 10 and 20 meters.

Some folks seem to prefer solenoid-wound air baluns, others prefer
scramble-wound. There seems to be a fair bit of disagreement as to
which style works better, and why.

The other choices are to use a different sort of balun (e.g. a W2DU
ferrite-bead choke), or none at all.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
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