I have a few junked vcr heads never really used them much apart from knowing they are well machined mechanically always found cd dvd motors and hard drive ones more to my liking due to size .
Looking into some ideas into the problem of rotating an on board led or light sensor the light sensor interests me a bit more but if worked out can take projects to another direction literally.
Powering every thing rotating and transfering data ,i hate the idea of slip rings but this DIY rotating slip ring using ballbearings seems good (first photo} and from this site
http://stephanschulz.ca/sts/howto/slipring.htmlAny case may be ok for powering but i bet they are all noisy for any signal transfer.
Powering the rotating led light or sensor via the VCRs rotary transformer sounds good ,looking into this i have seen 2 examples of using the head for this so far ...
http://us.cactii.net/~bb/propclock/index.htmlThis explanation from this rotating display[color=#FF4000]
In the base of the clock, a simple 555 based oscillator switches a power MOSFET at 100KHz, energising the rotary transformer's primary. The signal induced into the secondary is rectified by an FR104 fast recovery diode, then filtered and regulated down to 5 volts. I am able to get the necessary current to run the clock with this. I initially feared that there would be a lot of noise interfering with the micro, but this turns out not to be a problem.Also looks to me like this fellow on you tube used the same idea to use a 555 timer and mosfet to get 5 volts out of the secondary roatary transformer winding but i think its in spanish viewing guessing only for me
https://www.youtube.com/watch?v=_W_AB17pNp0https://www.youtube.com/watch?v=lFMDQaXvGA4Second photo and video it seems to get enough voltage for any little rotating circuit .
I haven't tried this my self but looks like a nice solution to powering a rotating circuit .
The rotary transformer i suppose has more than one winding and could be used one way or another for other signals in or out ...but you could by pass this and use a magnetic optical or even ultrasonic in the case of low bandwidth sstv ....placing the sensor top middle of the vcr head would not matter if its rotating or not they would always be lined up ...
Driving the VCR motor its self would make it neat ,i noticed Steve has a design in a a past newsletter but you could always belt drive the thing.
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.