back to epic tales of hidden transmitters

Flood Gate:


It was someone else's turn to hide the transmitter, and I was out on foot one afternoon with my hand-held
finder. It had been carefully constructed to find high powered transmitters even at close range. I had no
offset attenuator, so this was an old CB radio board installed into a metal box. The speaker was behind a
grill of holes I'd drilled with a hand drill. The knobs were mounted to the box. The channel indicator was
just barely visible through a hole on the top. The S-meter was mounted on the outside with a light, but the
wires to the meter and to the light were passing through feed-throughs in the case. It ran off a pack of AA
batteries inside the box. I had actually removed the audio chip after installing the speaker, to save power,
so it could run off the internal battery for longer. On the back by the coax connector there was a rotary
switch with three positions, for normal, -40db, and "disconnected" for the coax. These provided quite a bit
of attenuation.

For the antenna, I had a short coax running up a 3ft PVC tube, with an SO-239 on the end. I had three loop
antennas of varying sizes, along with a short spike that I could attach, I'd found the design could be used
to hunt either the peek OR the null, depending on how you held the unit. Upside-down would find the null,
and right-side-up would hunt the peak.

So I had been walking for awhile, following the signal that I knew was somewhere in the woods, and came upon
an earth dike. It was similar to those in Fletcher Park, though not as tall. I'd never been in this part of
the woods so I had no idea this was there. I eventually came to an opening in the dike, where a set of railroad
tracks passed through the dike, and there were huge metal doors that coul be closed in the event of a flood.

All my bearings were pointing to this location, and I was CLOSE. I searched all around the doors but couldn't
find any antenna or transmitter. Finally I switched to just the spike to basically put it into "sniffing" mode
to nail it down. When the transmitter started broadcasting, I started quickly swinging the unit around while
watching the meter for any slight movements (now that it was at the far right it was barely moving) but then
suddenly the meter actually PINNED HARD with a faint tapping sound. I looked up and finally realized I had
just touched the gate. ooooooooh. The gate IS the antenna. OK where's the radio?

So I set down my finder and again started searching the door. Nothing. Now these doors were swung open, but
on one side of both doors there was a box welded to the door. I knew those boxes are to store the large rubber
gaskets they use to make the door more water-tight when closing it. The lids were pretty rusty and hard to
move, but I opened one and of course there sat the transmitter and battery.

So the transmitter was INSIDE the antenna... I don't think I'll ever see that trick again.




last updated 11/12/2023 at 19:06:36