I'd like to construct a 15m vert that does not require use of my MFJ
Versa Tuner II. Portability. I started over this afternoon on a new
vertical using plans from a web site.

WIRING:
I've suspended an 11'1" #12 wire for 15 inside some pvc. (While I was
at it I also suspended a 16'5" #12 wire inside the same piping for 20m.)

RADIALS:
I've got six underground radials, 2 @ 11' and 4 @ 5-1/2"

FEEDER & CONNECT POINT:
Using 52ohm RG58 (the thin stuff) to feed into a female coax chassis
mount at base of system. I have a small (maybe 4") of line from the
center of the chassis mount leading to the connection point bolt/wing
nut for each/either wire. This wire is 4" and I suspect this 4" may
cause some electrical lengthening right? If it does, I'm over on
measurements for each. errr....

Other than this possible lengthening, I cannot think of what else to do.

In short, I should probably borrow a dip meter and check for impedance
problem? I was reading that I should attach a silver mica capacitor
across the wires. Haven't tried this yet as they are still in the mail.

I was thinking ahead too when I put this stinker up. I've got a 22-turn
base coil sitting there as my next try but that sort of defeats my
original simplicity plan.

73's-

-=Jon



w9gb wrote:

"J. Laub" wrote in message
...

I've constructed a 1/4-wave 15m vertical from 11' of 3/4" copper tubing
(water type). It's being fed with coax.

Much to my frustration, I am unable to get this thing to resonate w/o the
use of a transmatch. Any tips, ideas or good plans?

73's

-=Jon


Jon -

One of the old ARRL Antenna Handbooks (Green cover - circa 1973) had a 15
meter dipole constructed form 2 piece of 1/2 inch 10' electrical conduit and
a small coil wound from 1/8" copper or brass tubing (50 ohm coax fed).

The impedance for a vertical will be quite low (less than 50 ohms) what are
you using for matching?

15 meters / 4 = 3.75 meters (1/4 wave) ~ 12.3 Feet

Greg
w9gb