22-09-2017, 04:18 PM
(This post was last modified: 22-09-2017, 04:19 PM by Geordie McBoyne.)
Now that I'm getting into the business of modifying at least one of my pre-war first generation TVs to receive Baird type signals I find that the 240/25 and 405/50 system switch has to be a special three pole two way toggle type. Where will one find such a switch?
The attachment shows the problem. Line frequency and waveform shaping is easy, S1 tags 5,6,7. Frame timebase not so easy because the sawtooth forming capacitors C4 and Baird capacitor C3 are looped back to the output transformer primary and linearity control VR4.
Geordie McBoyne.
The attachment shows the problem. Line frequency and waveform shaping is easy, S1 tags 5,6,7. Frame timebase not so easy because the sawtooth forming capacitors C4 and Baird capacitor C3 are looped back to the output transformer primary and linearity control VR4.
Geordie McBoyne.
