[TowerTalk] which Baluns for 40m/80m Delta loops?

[Tom Osborne]

T A RUSSELL wrote:
> 
> A simple cost-effective method of feeding 100 Ohm antennas such as
> Delta loops is to use an odd number of 1/4 wavelengths of 75 Ohm
> coax or a single 1/4 WL of 75 ohm coax followed by any length of 50
> ohm coax.  For 1/4 WL  transformers, Rin X Rout = Zo X Zo.
> (Several friends are using RG-59 at 1200W with no problems.)
> 
> de Tom  N4KG

Hi all.
I agree with Tom.  The simplest way is to go with the 1/4 wave 75 ohm 
line.  I have used that setup for years.  If anyone saw how I did it, 
they would probably laugh.  I just solder the inner conductors together, 
wrap some tape around it, slip the braid over the tape, wrap some more 
braid around that, and tape it good.  Some of my loops have been up for 
years and no problems yet.  One of the first ones I put up, I put coax 
connectors on the end of the 75 and the 50 ohm lines, and used a barrel 
connector.  That was nothing but trouble!  Got hot and had carbon all 
over everything! BTW, that l'il antenna program I wrote figures the 
length of the matching sections if anyone wants it--for free!  73
Tom W7WHY


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