Hello Jim,
I have several miitary style gen purpose center insulators that had a
Military part number on them .
These were phenolic blocks screwed together, with metal hanging 'eye' ,
gaskets, N connector, and Screw on protective cap for the N connector...well
built...
HEY! I found a picture of one: See: http://www.fairradio.com/0il-4.jpg
I Google Searched "center Insulator" and got: A ton of useful sites. Do an
image search using same words...
This center insulator and a coiled coax balun to K1TTT specification as to
turns/diameter should get you a good balun. Check out:
http://www.k1ttt.net/technote/airbalun.html
Also, get the downloadable manual for the MFJ 259 from the the MFJ Site
and check it's procedure for field checking the effectiveness of your coiled
coax balun, at any given frequency.
I guess your dilemma is winding a coiled coax balun whose combinations of
diameter and turns and construction show no series resonances at frequencies
of interest.
73, DX, de Pat Barthelow AA6EG aa6eg@hotmail.com
>From: "Jim Brown" <jim@audiosystemsgroup.com>
>To: "Tower Talk List" <towertalk@contesting.com>
>Subject: [TowerTalk] DX Engineering Wire Dipole Baluns Discontinued
>Date: Thu, 21 Apr 2005 10:21:41 -0500
>
>I called up to order several more of the DX Engineering dipole baluns
>yesterday to build some Field Day antennas. I was told that they are
>discontinued, and that as a "replacement," I can order a balun in an
>aluminum enclosure. The reason given for discontinuing the balun was
>that its construction made it difficult to manufacture consistently.
>
>While I can accept that the relatively compact size of the
>discontinued balun might have been a limitation, I can't accept as
>fact that some other form of balun more satisfactory for use with a
>wire dipole than one in an aluminum can couldn't be built -- perhaps
>one in a longer tube that allows the coax to come straight away from
>the antenna for distance long enough to support the ferrite cores. Is
>there something else I'm missing? Am I limited to buying a bunch of
>cores and putting them on coax myself?
>
>And I still have to come up with a decent center insulator/support,
>which the discontinued part did QUITE well, and which the proposed
>replacement doesn't appear to do at all. Has no one at DX Engineering
>ever built or used a wire dipole, other than perhaps as an inverted
>vee supported from a tower?
>
>Jim Brown K9YC
>
>
>_______________________________________________
>
>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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