[TowerTalk] Strange Balun...please help

[Herbert Schoenbohm]

Thanks Doug.....It appears to be military surplus for a T2FD which are 
common at military and diplomatic installations as well as sent to 
National Guard com units that have no real use for them.



Herb, KV4FZ


On 1/25/2017 1:02 PM, Doug Smith wrote:
> 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.
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> Doug, W7KF
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>
>
>> On Jan 25, 2017, at 8:25 AM, Herbert Schoenbohm <herbert.schoenbohm at gmail.com> wrote:
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>> 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
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>> Herb, KV4FZ
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