Well it is not a T-match, Pete. A T-match does not have a split driven
element and th ends are indeed attached tot he driven element. Doesn't
sound like a Beta match either since there is no direct coupling to the
elements using inductance to match the feedpoint reactance. Sounds more
like a means of reactively coupling to the the elements with primarliy
capacitive coupling since the coax center conductor is inside the driven
element. The design of the coupling would naturally take into account the
feedpoint impedance R-jX (or in this case perhaps R+jX) in a fashion that
the R is the characteristic impedance of the coax and the jX is the required
matchin reactance. Neat idea.
----- Original Message -----
From: "Peter Voelpel" <email@example.com>
To: "'Towertalk'" <firstname.lastname@example.org>
Sent: Tuesday, August 15, 2006 6:53 AM
Subject: Re: [TowerTalk] TA-33 Classic Feed Model TAC-33K
> Hi Dave,
> To me that sounds more like a T-match
> -----Original Message-----
> From: email@example.com
> [mailto:firstname.lastname@example.org] On Behalf Of WA3GIN @ Arlington
> County, VA
> Hi folks,
> Just received a new TA-33M with TAC-33K feed.
> I've never seen a driven element feed like this one. Its a clever
> implementation. Where the two ends of the driven element converge at the
> boom a hollow insulated coupling is provided so that the two sections
> slip into the insulator, making the connection water resistent and
> eliminating the need to split the feed-line coax wand weather proof the
> coax shield, etc. In the middle of the insulator is an SO-239
> connection. Inside the insulator there are two pieces of coax (I'm
> guessing RG8) center conductor (shield removed but insulation remaining
> with the ends swrink wrapped) that are simply slid inside each end of
> the driven element. That is it. No direct connection to the elements.
> I'm guessing this is Mosley's version of a "BETA" matching system.
> Any thoughts on this technique or clarification as to whether this is
> indeed a "BETA" match?
> TowerTalk mailing list
TowerTalk mailing list