First live-TV-eye car.
R/C car chassis ready for video gear.
Bobble-head live-TV-eye car.
When the club decided to try remotely-piloted vehicles, we started
with the simplest vehicle, model cars. We got a common two-channel
radio-controlled race car. We chose one with a convenient high, flat
spoiler that we could use to secure the camera and transmitter base.
The smallest battery camera at the time was a Sony vidicon-tube black-
and-white model that was the size of a pack of cigarettes and cost $250.
It required 6 volts for power. We used AA cells. The transmitter was a
common home video sender of 100 milliwatts, normally used to send video
from a VCR to a TV set somewhere else in your house without stringing
cables. The transmitter used 12 volts. We mounted a flat plywood sheet
to the spoiler and mounted the camera, transmitter and batteries to it.
But it had a disappointing range. When we sent it down the hall and
into the chemistry lab, the video had severe snow and we were almost blind.
We did what we could with it but limitations were obvious. So it
languished about for a while.
Later we built a car of our own that was longer and wider and used 4
channels. So we could have the camera tilt up and down and pan right or
left as the operator's head moved. It was called Bobble-Head. The original
idea was to have a small LCD TV mounted on the headgear, connected to joy-
stick pots. As you turn your head, the car's camera would pan and tilt
to follow and you'd see the correct view in the monitor. Well, the car
still had very limited range and so we tried out the ideas but couldn't
implement it fully. The servos panning and tilting the camera were jerky.
And we used a fixed monitor instead of buying a special tiny TV that could
be mounted to a headband. We discovered that with the fixed monitor, it
was best to have the view not follow the head pivot, but move just the
opposite. So as you turn your head left, your gaze is right, so have the
right-hand view on the screen.
Years later, two things came about that allowed us to return to the
car and even go further. First was the advent of tiny, one-board B/W
solid-state "surveillance" cameras, and second was tiny amateur-TV
transmitters in the two-watt range. We ordered them and were back to
salvage the car idea.
The camera and transmitter both operate on 12 volts. We put the camera,
transmitter and rechargeable battery pack into a small box that weighs
13 oz. and we thought we were all set to go. Fools rush in. While the
the camera-transmitter sends a great, clear B/W image from a block away,
thru buildings and everything, it is so strong that it makes the servos
jiggle a little all the time. That's engineering.
We researched and found some magazine articles about getting the noise
out of where you don't want it, but by then we were moving on and looking
into another idea, the flight simulator. One tiny camera and the 2-watt
tranmitter were moved into the TV-eye rocket.
TV TRANSMITTER KITS:
North Country Radio
PO Box 53
New Rochelle, NY, 10804
Articles: 2-watt ATV transmitter:
73 (Amateur Radio Today) Magazine, Aug. '92, pp. 22-29
Sept. '92, pp. 50-56