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Old August 29th 08, 05:29 AM posted to rec.radio.amateur.antenna
John Smith John Smith is offline
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First recorded activity by RadioBanter: Nov 2006
Posts: 2,915
Default Coupling a T2FD to a S350DL

Bubblesdee wrote:

Hi

Thanks to everyone that responded.

I am a little confused but this is most likely my fault.

So i will simplify the question.

How could I transform from 300 ohm balanced antenna to 300 ohm
unbalanced line without using coax. I will do the transformation right
before the balanced (one antenna and one ground connector) on the
S350DL.

I think that all I need to do is come off the T2FD with 300 ohm Twin
lead and then into a 1:1 balun that does not use coax inside it but a
ferrite choke. Does this sound right? If so, then my next question is
DOES anyone know how to build a 1:1 balun not using coax to transform
300 ohm balanced to 300 ohm unbalanced?

Thanks again


This should get you started ...

Here are diagrams of one type of balun which will serve you well:

http://assemblywizard.fr33webhost.com/balun1.jpg

http://assemblywizard.fr33webhost.com/balun2.jpg

You will need to pick the proper material you need for the core, and
compute the turns necessary for the freqs in question (lowest freq will
determine these), there are abundant design pages on the web ... google
is your friend.

Regards,
JS