[TinCanAlley]

Originally Posted by DaveWM

the G2 is prob around 800v max, at 10x and if you have a 10v setting on the scope you should be able to read it, besides you will have the scope on AC so it should not matter. Start with 10x 10v then AC and then switch to lower and lower voltage settings on scope, that covers the G2, but there really should be no AC here anyway. Same goes for the cathodes.

G1 is where the video signal shows up (luma and chroma on this set) again start with 10x on 10v AC and work down the voltage, looking for a wave form pattern between Horz blanking pulses, the dark screen should be still a fair amount below the max amplitude found on the horz blanking pulse.

Generally speaking the horz video pulse should blank out the signal during flyback time, it is aided by the pulse from the fly that is fed to that blanking transistor (talking horz now) to furter cut off the CRT.


Zeno, any possibility this could be an AGC issue? maybe limiting the blacker that black region?

Tin Can give us a good shot of the CRT with the jail bars again with a transmitted blank screen. Adj the contrast and brightness to max and min the effect, then lets see some actual images using those same max and min settings.



the question that needs to be figured is
jail bars in video or sweep.


the below I really don't think is the issue, I still want to think its a blanking issue, not enough cut off to the CRT during flyback) but here it is:
as far as the horz sweep, you want to look at the rise time not the ringing after the drop off (that is a given and will always be there to some extent).

can you see the horz rise by holding the prob right up near one of the horz defection coil leads? if so look at the rise, is in smooth or rippled, the ringing you are showing in that other pic is I presume the ringing after the sudden drop off, not during the trace part of the scan. You want to see if the trace part is smooth.

Okay, give me about an hour and I'll provide the images you requested.

Also, the max voltage on mine is 5V/div. The manual says it +/- 250V DC plus peak AC at 20Kilohertz. I don't think I should go near the G2s, do you?