Ron Walters wrote:
After reading several articles both on and off the WEB regarding a
center fed antenna, only one article mentioned a recommended length for
the feed line.


There is a webpage that calculates the correct length of the feedline
for an antenna:

http://www.qsl.net/w4sat/howlong.htm


My shack is located on the second floor of a new home, (24') #8 ground
wire to 8' ground stake with a further connection to the common ground
point for the power and the rebar in the pored walls and flooring of the
basement, telephone and cable. I plan on additional ground rods around
the property and at a new tower. In a new home so progress is on-going.

The 1:1 current balum used to convert the 450 ohm balance line is
external to the tuner, use about two feet of coax from the balum to the
tuner.


Antenna is cut for 80 meters and using about 60-70 ft of line to center
of the antenna. Where the antenna lines leave the shack is about four 4
ft from the location inside of the rig and floor mounted PC.

I use the antenna on all bands until such time I complete a new tower
installation. I want to minimize stray RF around the shack since I rely
on a PC and digital sound card as my primary source for ham enjoyment.
I have already had some problems with a USB keyboard that I think may
have been effected by RF when running over 50 watts on 20 meters only.

One article recommended odd multiples of a wave length is desirable at
the lowest operating frequency while other articles don't address this.

Since you are using ladder line, you don't really want a hwole lot of
extra length, since you'd have to figure out what to do with it. Ladder
line doesn't like being wound up - note this is what I've been told, I
never experimented myself. But it stands to reason.

I am having no problem with a match using the tuner on all bands 80-6
meters.

The setup should work well. The grounding system isn't ideal, but we
work with what we have.

Have used the center fed antenna since 1976 but always had the shack on
the ground level and had a good and effective ground system short runs
with feed lines around the 90 to 100ft in length. never had a RF
problem or surge problem.

I'm not clear. Do you have an RFI problem now? Seems as if your steup
will work FB.

- 73 de Mike N3LI -