[NJARC] Antenna Balun

[Al Klase]

Scott Roberts wrote:
>
> .....Also, I have forgotten the meaning of the big black
> dot next to each transformer.
>   
The dot indicates the START end of the winding.  Phasing is important.
> And finally, are all three transformers 5 trifilar
> turns? (3 pieces wire, twisted, passed through one
> aperture of the core, with 5 reverses in direction?)
>   
One turn means you go though one of the holes in the "binocular" core 
and back through the other hole.  The exception is the designs that 
specify "in one apateur".  Then a turn just goes through one of the 
holes, and back around the outside.

Al

>
> --- Al Klase <al at ar88.net> wrote:
>
>   
>> Visit our web site - See http://www.njarc.org
>> _______________________________________________
>> Scott,
>>
>> For reference, go here
>> http://www.skywaves.ar88.net/ANTENNA/antsys.htm 
>> and open the "BALUNS" .pdf in the "Updated Info"
>> box.
>>
>> I'd start with the 9:1 "UN UN" as you're working
>> with an antenna of a 
>> random nature.  Of course connect the antenna to the
>> top, the cable 
>> shield to the bottom, and the center conductor to
>> the low-Z tap.
>>
>> As a further elaboration, if there's a ground near
>> the feed point of the 
>> antenna, you can try isolating the cable shield from
>> the antenna by 
>> adding a 1:1 current balun between the 1:9 and the
>> cable.  See the upper 
>> drawing under "Balun Applications"  This keeps noise
>> picked up inside 
>> the house by the cable shiewld from being applied to
>> the antenna.
>>
>>     
>
>
>   

-- 
Al Klase - N3FRQ 
Flemington, NJ 
http://www.skywaves.ar88.net/