In theory it should be possible to use a CRT as an amplifier valve. Any thoughts on this?
There is no voltage gain. The Anode is fixed at 25kv and never changes. Current changes and lights up the screen.The next question is, how do you run a valve in current mode?
The first TVs and CRT monitors I designed were based on 15,750hz by 60/30hz. The vertical scanned at 60hz buy only 1/2 the picture was display at a time so the entire picture came at 30hz. The video is updated at about 4 to 8mhz.What was the use Ron?
CRT has only 1 grid AFAIK - the rest are anodes. I was speculating they will still behave as grids with appropriate biasing.This isnt something I've played with much, however I have an old radio that uses the screen grid of one of the tubes as a diode as part of the agc, I wonder if you could use the grids of the Crt to do a similar function, sort of a diode clipper, as I guess a guitarist is only really interested in 'tube' distortion.
Dunno if this'll work on one of the grids of a Crt.
I have seen, and did, drive a signal into G1 of a CRT.CRT has only 1 grid AFAIK
IIRC in most TVs and computer monitors, G1 is grounded, and the cathodes are driven. you could use the focus electrode as a plate instead of using the dag anode there's also a G2 supply, and that's usually used for setting the beam current. G2 voltages used to be.... 200-500V, and the 1st anode (focus electrode) anywhere from about 1kV-5kV. in a 3-gun CRT. the G1 for all 3 guns are usually tied to one single pin.I have seen, and did, drive a signal into G1 of a CRT.
99.9% of the designs we held G1 at a voltage and drove the Cathode with a signal.
...Something like a grounded grid amp, grounded Base, grounded Gate amp
...The difference between G1 and Cathode is what it takes.
It varied with the design, for a LONG time it was common (probably back before IC's were more common than transistors?) to feed the three colour signals to the cathodes and the luma signal to the grid, thus combining them actually in the CRT. This made for a simpler design, but once IC's took over the combining took place inside an IC, and usually fed the cathodes only. Another common option was using the grid for feeding the blanking pulses, again this simplified the design.IIRC in most TVs and computer monitors, G1 is grounded, and the cathodes are driven.