That double wound stuff could be bought from Air Dux. Two of them made
a dandy 4:1 HF balun. The Heath was the only one I remember you could
buy complete with supports. Some folks removed the stuff from the box
or put away the cover portion indoors. There was something going
around about how the box caused losses, never proven, source unknown.
The ones you saw on standoffs on the shack wall were home built from
the Air Dux stock.
Never saw anything about efficiency or power handling. Ran KW (800W
out) on em and never melted it.
That was in the late 50's early 60's. Stuff sorta went away when
torroids became commonly available. Haven't seen any of those on EBay,
even.
Guy.
----- Original Message -----
From: "Jim Smith" <jimsmith@shaw.ca>
To: "List TowerTalk" <towertalk@contesting.com>
Sent: Tuesday, April 09, 2002 3:07 AM
Subject: Re: [Towertalk] 1950 era Balun ?
> Sounds like the Heathkit B1, except it's in a box.
>
> VE7FO
>
>
> Jim Reid wrote:
>
> >Anyone recall the name/mfg of the open wire coil
> >balun we were using in the '50s. It was on a small
> >plate, maybe 3" x 5" or so; had two open wire, air
> >core coils, maybe 4" long each. Output from the Pi
> >network, or single end final you had went to one coil pair
> >end of the plate. Folks mostly were using 300 ohm
> >twin lead to Amphenol or other, folded dipole antennas.
> >The balun provided the link between the single ended
> >transmitter output and the twin lead fed dipole.
> >
> >Earlier, the final output was usually a "swinging" link
> >coil, and the ladder line was connected to terminals to the
> >two ends of the link coil. The two swinging link coil ends
> >served as balanced output terminals and the "antenna
> >tuner/matcher" of those days. However, TVI problems
> >pretty much killed-off these sorts of set ups!
> >
> >Couldn't recall the names about the balun, so thought
> >I would ask.
> >
> >73, Jim KH7M
> >
> >
> >
> >_______________________________________________
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> >Towertalk@contesting.com
> >http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
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