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Re: [TowerTalk] Strange Balun...please help

To: Herbert Schoenbohm <herbert.schoenbohm@gmail.com>
Subject: Re: [TowerTalk] Strange Balun...please help
From: Doug Smith <doug@w7kf.com>
Date: Wed, 25 Jan 2017 10:02:40 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I’d expect those to be flux coupled RF transformers designed for use with 
terminated antennas.  Think rhombic or vee beams or terminated dipoles.  Any 
chance they’re actually 800 ohms on the load side?  A four to one turns ratio.  
I’ve seen such things in military and commercial settings.

Doug, W7KF



> On Jan 25, 2017, at 8:25 AM, Herbert Schoenbohm 
> <herbert.schoenbohm@gmail.com> wrote:
> 
> I came into the possession of two unusual high power baluns, one with 125' of 
> RG-213 attached and the other with a two foot lead of coax attached.  They 
> are seal and inside PVC with the coax going inside the bottom and large 
> eyelets for the wire and support in the center. They appear to be 
> commercially made.  I soon found tat they are not current baluns judging from 
> the discovery that there is no DC continuity to either wire connection from 
> the coax.  With a bridge and a 50 ohm non-inductive resistor the VSWR is very 
> high.  However when I put a 1000 ohm resistor on the antenna connections the 
> balun is flat from 1.8 to past 60 Mhz.  This would make the device a 20:1 
> balun which is something I have never heard of. What kind of antenna requires 
> such a high impedance feed?  If anyone has any knowledge of the use for these 
> devices please let me know. Thanks
> 
> 
> Herb, KV4FZ
> 

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