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Old August 26th 05, 06:03 PM
Ken Bessler
 
Posts: n/a
Default Blowing up a VLF converter

I was looking for an antenna for my LF/VLF converter.
The converter is from Jakson Harbor Press and uses a
SA602 chip to convert 10-400 khz up to 14.010-14.400.
It has 2 five pole L.P. filters (cutoff @ 500khz).

For $12, it can't be beat. Anyways, I've got it running
and everything that should be grounded is grounded. I've
got a antenna lead with an alligator clip on it and I'm
probing around, listening to WWVB. I try my 40m inverted
V (fed with ladder line & coax). I get a pretty good signal
on the "hot" side (the side that connects to the center of my
coax) but also I get the same signal from the ground side so
I left it there.

The path for the 40m antenna is radio/coax/coax coil/ladderline/
antenna. The converter is hooked to the junction where
the coil transitions to the ladder line. It's just a pl-259 with one
side of the ladder line going into the center pin and the other side
soldered to the shell. I figure I'll just go out and unhook the
converter's antenna clip when I use the 40m antenna.

Getting gutsy, I decided to see what would happen if I didn't
unhook the converter and transmitted into the 40m antenna
I tried 1/2 watt - no damage. I then tried different power levels
finally ending up with a 15.2w CW carrier. No damage!

I thought I'd blow my little converter. Anyone care to educate
me as to why it didn't blow? Would it have blown up if I had
hooked to the other side of the ladder line? Did the 2 five pole
low pass filters save it?
--
73 de Ken KGØWX - Flying Pigs #-1055
Elecraft K2 #4913