This transmitter and receiver pair is delightfully simple to
build because most of the hard yakka is already done for you.
The transmitter and receiver are both pre-assembled modules –
all you have to do is solder them to a couple of PC boards, add some power
supply components, a video source . . . and that’s it!
The transmitter board is not much bigger than a postage stamp
(actual size is 30mm square x 13mm high
[not including antenna]
), so if you
wanted to, you could conceal this little board virtually anywhere (eg, for
surveillance/security or even hazardous area monitoring applications) and have
the receiver feeding a monitor some distance away.
The 2.4GHz band
Once upon a time, 27MHz was regarded as the "garbage band" –
just about anything and everything was chucked in there, including model
control, garage door controllers, industrial, scientific and medical equipment
(that, in fact, was/is what the band was called) – and even the first CB radios
and low-cost marine radio transceivers (which of course exist to this day).
In recent times, 2.4GHz has earned much the same reputation.
You name it
and it’s in that frequency band – every-thing from microwave
ovens to WiFi and Bluetooth, cordless phones and doorbells to almost limitless
types of "wireless" links. And of course, all sorts of A/V equipment.
Which brings us to the reason for this interlude: there are
three channels to choose from in the system presented here to hopefully allow
you to avoid frequencies which are already in use (we’ll go into setting
channels later). You may need to experiment to find which one is right for