The Sinclair QL Forum

hello again....
the problem.... in f2 fuction (monitor) in a scart crt tv... the ql has a bigger idol that the crt can give
the solution .... someone say that can take a resizer (its a component that can give a vga also)
my solution (actualy not mine ) i coil from ferite handmade in series with big return capasitor on the h-yoke circuit....
(ferite its use on old radios) h yoke has hi voltage 250 and hi amp so the widdings must be from thick cooper wire... 0,50 its ok or more
more turns...narrow image...... less wider
now for v-- size a resistor of 0.5 ohm 5 watts on the return of the coil in series will be just fine \
more ohms sorter less taller.... in my philips 14 crt the v size and position can be change by....pontesiometer...that was the half of job...
the hack can be in most old crts....

By doing this you also change the effective acceleration voltage for the screen, to a HIGHER value, as well as the retrace current, which stresses the HV transformer and rectifier, as well as the damper diode. So... do this at your own risk, knowing that there are no spare old CRT TVs

Nikosdoykas,
in a sense, your courage in taking your own risks is admirable. You're trying to solve an old-standing issue. And you almost did it, but the problem now is to find a safe way to realize the hack.
My knowledge is poor, maybe someone else can help?

http://www.nightfallcrew.com/23/09/2014 ... -computer/

look

Increasing the EHT will make the picture smaller, as the scanning coils will have less time to move the electron beams side to side, and up and down.

Also for anyone who's thinking about trying it. There's is a lot more than 250 volts lurking around there, more like 25,000 volts. Even when switched off.

The Prism monitor in the above link. Is that a Fidelity chassis without all the RF circuitry? It's been a VERY long time since I left the TV trade, but the insides of that monitor looks vaguely familiar.

and have the two.... ferite coils on the yoke field for the horizontal size.... hehehehehe
so was no my idea....