Next month my daughter's 6th grade class is
going to Big Bend camping & hiking. Soooo,
dad is gonna go too.. gotta take the Sierra &
have some fun! What about an antenna?
Well, I'm not sure if there will be trees where
we will be, so I figured I'd make one of the
SLV vertical types & try it out... I looked all
over Austin, and can't find one of the SD-20s...
guess you don't need a pole like that to catch
catfish & perch!! However, at the local wally-world,
I did happen onto a 13' pole called a Black Widow.
At $11.95, I figured I'd play with it a while.
Since the vertical dimension wasn't the same as the
SLV, I also figured that maybe I'd make a 'real'
loading coil at the bottom & feed with rg-58 &
a tuner.
One main point that I forgot is that it needs to
work for 80 meters! The XYL (KA5KOA) has one of
the 'real' tech+ licenses... she went through the
FCC office & code intimidation quite a while ago!
Anyhow, she expressed interest in trying her hand
at code & keeping a schedule while we were gone.
Oh, Boy, I couldn't pass that one up! But, at
night, when I could do the sched, I think the only
reasonable band will be 80 meters for the path length.
Back to the coil winding party... I got about 40uH
wound on a toroid, & then it seemed to tune up pretty
good with the old homebrew or MFJ 940B. Could hear
good signals, but nobody heard me.. even with the
Wis QSO Party going on, nobody returned my call. Oh,
well, let's short out the coil, and load up on 40.
Oh, BTW, I did add another 4' chunk of 3/4" PVC pipe
to get the height at 17 feet. Well, it loaded up on
40 pretty good too, but again, nobody would answer me.
Called a lot of pretty loud cq'ers, but to no avail.
-enter idea-
Had done some playing with helically wound things back
in the old AF back in '77, hmmm, maybe I should try it
here. I wound #24 gauge wire around the old black widow,
and it equaled to about 45 feet worth of straight length.
I hooked up the 3 radials (60' each), and the MFJ SWR
analyzer, and it was resonant about 8.4 mHz. As I speak,
I am winding #28 gauge wire around the pole, and will
check it's resonance point a bit later. However, even
if it is good, and seems to work, it's really not
feasible to sit for 30 minutes wrapping a rod!
Anybody have any suggestions?
Thanks!
Tim W5FN
[
QRP-L Archive |
]
[
1993 |
1994 |
1995 |
1996 |
1997 |
1998 |
1999 |
2000
]