[Lowfer] Thunderstorms!

[Ralph Hartwell]

Well, here in South Louisiana this evening, 'tis not a good night for LF
work!  Thunderstorm static is +20 over; the Spectrum Lab screen is solid
white.  I can barely find the calibration signal from my BC-221.  Lots
of rain outside.  Luckily, no local lightning - most of it is just off
the coast south of us.  Maybe better DX WX in a day or so.

Last weekend, I put up the new antenna tuning cabinet on the bottom of
my tower, and installed 1/2 of the variometer I show on my web site.  I
separated the two buckets of "L" since the combination was too large to
fit inside the cabinet.  (More pictures and text to follow on the web
site, Real Soon Now.)

By placing the second bucket atop the tuning cabinet and putting it in
series with the antenna, I can tune the antenna between 485 and 165 Kc
by using the variometer and the appropriate inductor taps.  This is with
the 50 foot long temporary "hank of old wire" antenna I strung up one
evening.  I plan to put up something more substantial for a skywire,
just as soon as I do some more simulation runs to determine what will
work the best (or the least badly) at my QTH.

The measured combined loss resistance of the antenna + coil + ground
resistance is:
166 KC  = 50 Ohms
460 KC  = 18 Ohms
1900 KC = 35 Ohms

Which is terrible, considering that the calculated radiation resistance
of the antenna is close to 0.05 Ohms.  Oh well, O always wanted to plow
in 15,000 feet of copper wire...

73,

Ralph   W5JGV / WC2XSR / 13

http://home.att.net/~shmrg

http://home.att.net/~ralph.hartwell