[TowerTalk] Needed: Balun and Unun text by W2FMI

[Tom Rauch]

Two transformers each with a core independent of the other
transformer.

73, Tom W8JI
----- Original Message ----- 
From: "W7RY" <w7ry at centurytel.net>
To: "'Tom Rauch'" <w8ji at contesting.com>
Cc: <towertalk at contesting.com>
Sent: Wednesday, August 31, 2005 8:06 PM
Subject: Re: [TowerTalk] Needed: Balun and Unun text by
W2FMI


> What do you mean by a single core Tom?  Do you mean that
this type of
> balun requires 2 cores stacked on top of one another? Or 2
cores making
> up 2 actual transformers?
>
> Could you please explain that?
>
> Thanks!
> 73
> Jim W7RY
>
>
>
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com] On Behalf Of Tom
Rauch
> Sent: Wednesday, August 31, 2005 4:58 PM
> To: Tod - ID
> Cc: towertalk at contesting.com
> Subject: Re: [TowerTalk] Needed: Balun and Unun text by
W2FMI
>
> I concur with Tom's evaluation -- the later editions are
> better technically
> -- I have both the original and later editions.>>
>
> The edition I kept was third printing 2002 by CQ
> Communications.
>
> The only real snafu's I've found in that printing are with
> the evaluation of a dipole and why it needs or doesn't
need
> a balun (the theory is incorrect and the test of a dipole
> isn't a valid test) and some statements that a single core
> can be used to make a 4:1 current balun using a pair of
> transmission line mode transformers. MFJ actually built a
> 4:1 balun that way and the balance is very poor. As a
matter
> of fact it really doesn't act like a balun, let alone a
> current balun.
>
> The exception is a conventional primary-secondary mode
> transformer. That type of system CAN be wound on a single
> core in any ratio, since it is in effect just an isolation
> transformer. True transmission line mode transformers like
> Sevik describes, other than a 1:1 ratio, cannot be placed
on
> a single core without screwing up balance.
>
> 73 Tom
>
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting
Towers", "Wireless
> Weather Stations", and lot's more.  Call Toll Free,
1-800-333-9041 with
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
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> TowerTalk at contesting.com
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>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting
Towers", "Wireless Weather Stations", and lot's more.  Call
Toll Free, 1-800-333-9041 with any questions and ask for
Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>