[Lowfer] Alien e-probes

[Peter Barick]

Jay, Bill, others,
Re: Ground Planes

Yes, the W8JI site is a new and eye opening all around. Impressed by
his shop building (read outa the house!) and components therein. Way to
go if one "gotta build."

Fine on the lackluster 10-meter radial application mentioned. One Jerry
Sevick reached this conclusion in several QST articles in the 70s. As I
recall he took a pot shot at the then CB rage and the cheep pole
antennas being manufactured for that market, in some case using 3 or 4
little stub radials at the base, "good buddy!". So he showed the sense
of laying down ample radials for a ground-mounted vert., as in BC
systems. Fine, but what about a raised vert? Seems intuitive that a
compromise is in order. Then how much tradeoff is tolerable, and that's
the point of my query.

When mounting a LF probe high on the tower, what to do for a GP? a)
forget about it as nothing practical is ever going to be effective at
LF, b) strap it to the metal mast and grounded tower, c) use 10 or so
end-connected 4-foot radials to establish a local GP ?

I tend to seeing "c" as starting point, with the feedline tied to the
tower.

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>>> advancedreceiver@snet.net 09/16/03 12:39PM >>>
Peter

Check out the page below from from W8JI's website...about half way down
he
shows an Eznec plot of a ten meter ground plane. Antenna lore would
have us
believe that the four full size radials constitutes a "good" ground
plane
when in fact it is rather poor.

Getting adequate feedline decoupling with an above ground mounted e
probe
might be quite a challange. Would be fun to try Bill's 5000 X 5000
copper
top hotel with the e probe mounted in the center!

http://www.w8ji.com/common-mode_noise.htm 

He's got lots of interesting stuff on his site as well.

Jay