Re: Type 503 Oscilloscope Issues


1. For the diodes, those values are from my multimeter in diode testing mode, but it does not display any units associated with the reading (so I am assuming it is in volts).

4. C614 gives a resistance of 3.2 ohm, so it would seem that it checks out.

I also checked the burnt black stuff on the wires, which did peal off with some isopropanol. It appears to be just melted plastic, and it is not from the yellow wire (since that was clean underneath). As such, the burning smell may have just been old plastic and dust from various loose components that were not cleaned off initially (for example, the rubber casing around the CRT connector has basically dried and disintegrated at this point).

As for the -3000 V supply to pin 5 on T601, it gave a resistance of ~4.40 M-Ohm (my multimeter reads up to 20 M-Ohm, so it should be accurate).

With the video, the only thing with V659 was that it was flickering on and off (which is accurate in the video no matter the angle), although it is difficult to make out the behavior of V620. Again, the issue that I observed with that was just the blue electron streams around the sides of the wall, and then the redness at the center of the metal plate in the tube.

I won't be doing any voltage testing until the new fuses come in, and they are the correct type (1.25 A, Slo-Blo), so nothing to worry about with the dangers of higher rated fuses. I do not have any AFCI or GFCI outlets available unfortunately, so I will just be very careful in the live testing once I get to that point. However, I will be sure to check what I plan on doing here before proceeding, since I definitely do not want to fry anything (or myself for that matter).

- Evan

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