Robert:
I homebrewed a balun for my 3L Yagi. I'm not sure how to tell if it's
doing any good, but I installed one 'cuz the manufacturer said I ought to.
Unlike you I wound mine as a separate unit, with PL-259 at the feed end
and terminals at the antenna end. I connected it to the main coax through a
barrel connector (PL-258, I think) and lots of tape.
Mine is made from RG-213 and consists of five turns wound around a small
paint can about four and a half inches in diameter. I determined the number of
turns by winding eight or so turns around the form and connecting the coax
shield to my MFJ259 analyzer. Note: I ignored the center conductor for this
measurement and connected the coax shield as if it were a large-diameter
conductor. I then measured the impedance of the solenoid balun as I ran the
MFJ through the HF range. I took off turns until I got somewhere around 250
Ohms (5 X 50 Ohms of the coax) of inductive reactance across the HF range. I
held the solenoid coil in place with tape and used quite a few large plastic
wire wraps and tape to help the coax hold this shape when I removed the can.
The PL-259 at the feed end is easy. Sealing the antenna end from the
weather is a bit trickier. I posted this:
http://lists.contesting.com/archives//html/Towertalk/2002-10/msg00391.html on
TowerTalk after I had installed my own balun. Hopefully it will help you, too.
73 de
Gene Smar AD3F
> hi,
> i am getting ready to install a h/brew 2 el 12m yagi. i scrounged the
> reflector & split driven ele. off an old Mosley. I am thinking of h/brewing
> a
> balun. Arrl handbook gives apx size on a coiled up one. i am thinking more
> along
> the line of wrapping one arnd. 2'',3'' or 4'' pvc. anyone rolled ur own out
> there? was also considering making this 'in line'. Just rolling it at the
> end
> of the coax feed line with no breaks or connectors before the feed piont. i
> might just skip the balum altogether. i've used split d/ele feeds with and
> without and i tend to think the balun helps. i'm interested if any readers
> have
> made their own baluns and the result.the antenna is from an article by
> Cebik.
> it has a 6' boom to help make the impedence closer to 50 ohms.
> k9il
> _______________________________________________
>
> 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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_______________________________________________
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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