On 11/4/2012 1:44 PM, kb8viv wrote:
Thanks for the reply. At this point I may just forego the balun all
together and continue to just feed theloop with coax. Thanks again es
73's.

Kb8viv





I have a 75 meter loop. I feed it with 600 ohm open wire ladder line. I
have experimented with coax and window line.

The 600 ohm ladder line is extremely low loss. This makes up for the
nasty mismatch on 75 meters. This scheme got me an antenna that works on
10, 15, and 20 with no tuner. The VSWR is less than 1.6:1 on the worst
spot on these bands.

I use this antenna mostly on 75 meters and it works very very well. For
some reason I cannot say, the side null of noise from town increased and
I got less noise on all bands switching from 450 ohm window line to open
wire ladder line. I cannot explain why this happened. It is very nice to
see a S0 noise reading on 20, 15, and 10. My 75 meter noise is still
between S2 and S3. However, that is quite a step up from what I had
originally.

I think the good match on the high bands is because the loop feed point
gets higher in impedance at the higher frequencies.

I checked my worst case losses with a calculator on the web. It is found
here http://www.kc9aop.net/HAM/antenna_fa...line_loss_calc

Mine calculated out to be about 1/2 db at 75 meters.

Michael

Hi Michael,

Tnx for the reply and info. At this point it works well, so I think I'll just run the coax with a few loops at the feedpoint and call it fit for service. Tnx agn es 73's.

Kb8viv