[TowerTalk] TA-33 Classic Feed Model TAC-33K

Bill Gode, Sr. w9nhq at comcast.net
Tue Aug 15 10:18:52 EDT 2006

It's called "Balanced Capacitive Matching" and is described on Mosley's 
web site.  Scroll down the following page and look for the Classic Feed 



Bill - W9NHQ

----- Original Message ----- 
From: "Bill" <w7vp at comcast.net>
To: "Peter Voelpel" <df3kv at t-online.de>; "'Towertalk'" 
<towertalk at contesting.com>
Sent: Tuesday, August 15, 2006 9:06 AM
Subject: Re: [TowerTalk] TA-33 Classic Feed Model TAC-33K

> 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.
> 73
> Bill
> W7VP
> ----- Original Message ----- 
> From: "Peter Voelpel" <df3kv at t-online.de>
> To: "'Towertalk'" <towertalk at contesting.com>
> 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
>> 73
>> Peter
>> -----Original Message-----
>> From: towertalk-bounces at contesting.com
>> [mailto:towertalk-bounces at contesting.com] 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?
>> 73,
>> dave
>> wa3gin

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