On 2/23/2010 3:13 PM, TOF wrote:
I have a (home built) 40 m ground plane with the base elevated about 8
feet and with 7 elevated sloping radials. The 50 Ohm feedline drops
straight down the 8 feet and then runs on the surface of the ground.

Would a choke balun at the feed point be advisable?

W0BF


If rf is on the feedline, to a noticible degree, there is an easy
indication I have found and think worthwhile to look at. That is, a
field strength meter placed at a strategic point to make it more
"susceptible" to the rf on the feedline. Now move the feedline. If the
feedline is carrying enough rf to worry about, you will see it, at
least, that has been my experience.

The only problem with the above are those "weird" antennas where the
feedline actually plays a role in the antennas performance ... so, use
with caution.

I don't believe rf on the feedline is what you want with your groundplane.

Regards,
JS