Jim Thomson wrote:
> http://www.dxengineering.com/Parts.asp?ID=3585&PLID=50&SecID=10&DeptID=9&PartNo=DXE%2DBAL450%2DH10%2DB%2DP
>
> Has anybody uses these items or similar ?? The concept is a 1:9 balun at
> each end of a 300-1000' run
> of 450 ohm line... then 50 ohm coax up a tower... that happens to be
> 300-1000' away.
>
> I thought of this same idea back in the 80's, but was always on a small city
> lot, so discarded it. [still am]
>
> I suggested the concept to other folks who were on acreage, and nobody tried
> it...or even tested the concept.
>
> DX eng claims .2 db loss for EACH of the 1:9 baluns [ but no freq is
> spec'd ] From their chart, it appears
> to be aprx 15m band ? You also have the loss of the actual 450 ohm line
> itself.
>
> Heck, if you did it right, you could even run the 450 ohm line up the side of
> a tall tower, using
> some creative stand off's of course. They used standoffs back in the
> early 60's, to stand off 300
> ohm line going up the side of a AL mast on a typ roof-top for TV ants.
>
> later.......... Jim VE7RF
I have been running a homebrew system of this type for over 10 years.
The 1:9 baluns are homebrew and instead of using ladder line, I use
homebrew open wire line (4 AWG at 5 inch spacing). It is 850 feet
long and I use it for low bands (up to 30 meters). However, my
baluns are good up through 6 meters. I highly recommend the
concept, although I have never tested the DXE components. There
is a major disclaimer about this. I operate my line "flat," ie
with low VSWR. What many people want to do is use only one of
these DXE baluns and connect the other end of the line to
some multiband dipole or loop, and then use a tuner at the
rig end. This could produce extreme voltages
that may cause the balun to fail. I DON'T recommend that.
Rick N6RK
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