miso@sushi.com wrote:

They can't just turn on this camera when they think someone is
snooping. I'm guessing one of the road sensors is used to either turn
it on and start recording, or to alert security, which can then turn
on the camera.

Still, the question of "how is it turned on?" bugs me.
If it's a road sensor, how does that local sensor transmitter
trigger the tripod camera?

There doesn't appear to be any long distance means of
controlling it, as the yagi coax is cut, as RV58 notes. If this
tripod is where I'm assuming it is, the dish (if that's what it is)
doesn't have any kind of clear line of sight to the base. Perhaps it
has a clear shot at some other dish, up on Bald.

But -

That's a pretty small round item to contain the dish,
and associated transmit/receive/convert/LNA circuitry.
Not impossible, but it looks like if it did contain the
parabola, it wouldn't have room for the other circuitry.
The cable coming out of the round item is obviously not
a waveguide. It's either coax or power (or both). So the
round thing has to contain all of the RF circuitry. It does,
however, appear to point in the same direction as the Yagi,
suggesting that it indeed is some kind of dish. It also
appears to be the typical, generic color of lots of
simple link dish radomes.

The Cohu camera appears to be an older model. The newer
models output an RS-422 type data signal. That's a really
thick cable in the pic, just to handle a simple data signal.
Maybe the older models are video output. In either case, some
kind of modem, or other convert mechanism, would have to
modulate the signal into RF to be transmitted anywhere.

The rectangular NMEA looking box is barely big enough to
hold a typical 6v gel cell. Plus it would still have to
have room for the termination of the two cables. Hard to
imagine it would contain modem circuitry, plus the
exciter radio circuitry, plus the receive/decode/control
circuitry and still have room for a battery and cable
connections.

Look at the zoomed in version of the photo. I think I can
see a piece of RG-58 sized cable coming out of the bottom
of the rectangular box. I can't tell if it's the cut piece
that used to join with the Yagi or maybe it runs under the
tripod legs to the ground (and then to some other circuitry,
battery, sensors etc).

Perhaps the "dish" is a photo sensor, crossing the path
of the "gate". Seems at a strange angle, though, compared
to the camera. But then, of course, the question is
"Where does the video signal output from the camera go?".

It's almost as if they cobbled together a bunch of parts,
not necessarily related, to make it look like a camera.

Do you have any pics of the other tripod cams, like the
one(s) above campfire hill area? Or how about the new
tower south of the main gate? Let's compare what they
have for "accessories" to this frankencamera.


Craig 'Lumpy' Lemke

www.n0eq.com