[Top] [All Lists]

Re: [TowerTalk] Pattern Distortion caused by faulty balun?

To: "'Tony'" <>, <>
Subject: Re: [TowerTalk] Pattern Distortion caused by faulty balun?
From: "Scott MacKenzie" <>
Date: Sat, 31 Dec 2011 16:42:47 -0500
List-post: <">>
There is a program called PolarPlot )( that can help map out your
pattern fairly easily.  All you need is a constant RF source at the
frequency desired, and you rotate your beam and the pattern is measured.
Really pretty cool.  I have used it for my 6M beam with good result. 

Scott aka KB0FHP

-----Original Message-----
[] On Behalf Of Tony
Sent: Saturday, December 31, 2011 2:38 PM
Subject: Re: [TowerTalk] Pattern Distortion caused by faulty balun?


Jim Browns paper on baluns and chokes is very informative. It's written so
even a layman (like me) can get the gist of what a choke is supposed to do.

As far as I can tell, the pattern on my M-Squared 5 element mono band Yagi
seems fine. I use the  calibrated s-meter on my Flexradio to check the
antennas pattern. It measures signal strength in dbm as well as s-units and
the front-to-back varies between 18 to 24db (sometimes a bit more). The
overall pattern seems fine.

That said, I'd still like to check the to see if the M2 balun is isolating
the feed line from the antenna. It's not exactly tower work weather here in
the northeast so I was wondering if there's a way to see if the balun is
doing it's job from inside the shack?


Tony, K2MO
> On 12/30/2011 10:25 AM, Tony wrote:
>> I'm told there
>> are better baluns available and was wondering if you could recommend 
>> one that has greater isolation capabilities -- or at least one that's 
>> known to work well.
> Sure. I've done a lot of research in that area, and published the 
> results in
> I don't recommend any commercial products because nothing I've tested 
> is very good or even worth the cost, and because it's VERY easy to 
> make your own VERY GOOD one by winding turns of coax through some 
> ferrite cores. Specific recommendations are in the Choke Cookbook 
> chapter of the above reference. Appendix One lists part numbers for 
> the ferrite cores and some recommended places to buy them at reasonable
> 73, Jim Brown K9YC
> _______________________________________________
> _______________________________________________
> TowerTalk mailing list


TowerTalk mailing list
No virus found in this message.
Checked by AVG -
Version: 2012.0.1901 / Virus Database: 2109/4714 - Release Date: 12/31/11


TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>