24-09-2020, 12:20 PM
Some more progress today.
I was wrong there is CRT protection but its been bypassed no doubt due to a short circuit capacitor 0.1uf that I found. Protection now working and no frame sync sorted, due to very leaky 1nf sync decoupler. Picture very good indeed so just the decouplers in the tuned circuits and valve bases to attend to.
The video amplifier anode load is 2x 47k down to 5k the old body tip spot types. This gave no brightness once the protection was fixed, again I think the 1950s bodger was stuck with the fault.
I was wrong there is CRT protection but its been bypassed no doubt due to a short circuit capacitor 0.1uf that I found. Protection now working and no frame sync sorted, due to very leaky 1nf sync decoupler. Picture very good indeed so just the decouplers in the tuned circuits and valve bases to attend to.
The video amplifier anode load is 2x 47k down to 5k the old body tip spot types. This gave no brightness once the protection was fixed, again I think the 1950s bodger was stuck with the fault.
