Yes, Thanks for the test set up. I did the current test by lifting one lead and then with 10V with 1.2K series resistor got 0.74V forward. I think I did not have my DMM leads in good contact on those

Diode question, Checking the HV section diodes in circuit using a Fluke 8024B diode selection, some diodes show normal forward reverse, but several show nothing (open). Diodes CR1651, CR1664 and CR166

How do I test a leaky HV cap or diode? Particularity in circuit. All I have is two PS503A's which will only combine to 80 volts. Also, I am nervous enough using the HV probes. Setting up a bench HV te

Unfortunatly no.

David, Actually the PS only ticks when I touch the filament line with an HV probe. And then only temporarily. It comes back on after a few ticks even with the probe. Eventually it stays on even when p

Hank, Thanks for the suggestion. Is does have a sweep out. Just checked it and it looks like a normal sawtooth that varies properly if I change the sweep frequency from the 485 front control. Bob

left out photos are in Photo section under album "485 No Trace"

Picked up a 485 recently with the expectation of it being a parts scope. However, when I had a chance to look at at, it seemed complete and then Gasp, need air, getting sucked in, fix this scope... (

For some reason 7603s seem to be pricier recently. Bob

I once had a Tek 442 that was slow to turn on that way. Changing out the PS filter caps fixed it. (on that scope including a filter cap in the HV supply feed) Bob

Also check the MB e-caps. I have fixed a number of broken Dell PCs' that way. (real nice as they were given to me free, and parts about $10, with shipping). Bob

Gabriel. Looks interesting. Also, I wonder if the adjustment knob on that 10 turn pot is easier to re-attach than the orginal. After working on my SG503, getting the level adjustment knob back on seem

My TG501 does not have option 1. As for the SG503, well yes, it's really about level. The freqeucny reference was just an idea. Bob

Dennis, Test results would be welcome. I have thinking about upgrading my standard TG501 and SG503. Bob

My multi bit set has both. Bob

Thanks, I live very near Sacramento. As I have several 7603 (but who couldn't use another?) if someone else really needs it, I won't compete. Bob

Great! After adjusting the bias for max using the calibration square wave. I readjusted the Vertical gain for four divisions of the 4 volt calibrator signal. Now when I move the square wave signal up

With no vertical plugin, the trace is about one trace width above the center gratical. Pretty close, so I will try the bias adjustment using the calibration square wave. Bob

Not yet. In my manual, page 3-9, it indicates I need a standardizer. Is there a way to make this adjustment (R4860) without the standardizer? Bob

Thanks, I tried it. The compression at top and bottom starting at a full 4 Div for the 1 Volt Calibration signal while centered still goes down to three Divisions as I move the trace up or down. The v