[TowerTalk] back to back baluns..with 450 ohm between em.

[Mark Robinson]

----- Original Message ----- 
From: "Richard (Rick) Karlquist" <richard at karlquist.com>
To: "Jim Thomson" <jim.thom at telus.net>
Cc: <towertalk at contesting.com>
Sent: Saturday, 17 July, 2010 9:16 AM
Subject: Re: [TowerTalk] back to back baluns..with 450 ohm between em.


>
> 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
> _______________________________________________


I am seriously contemplating using this system to run out to my planned 40m 
4 sqaure in the back field. I can run the ladder line at 12 feet between the 
trees and then along the fence lines on fiber glass poles such as the ones 
sold at Tractor Supply Company.

http://www.tractorsupply.com/electric-fencing/electric-fence-step-in-posts/sun-guard-ii-fiberglass-post-360098099

Mark N1UK