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Mark, Thanks for the help! Greatly appreciated! I am thinking the Bias pot is R873, its labeled Beam. Last week I found that pot had come apart. No trace. If I pressed down on that pot the trace

At issue is that the stretching occurs even when the trace is not extended past the top or bottom graticule. It isn't horrible but quite noticeable. I have another 7704A, two 7603s, and a 7514 and

Harvey, I think we are talking about different things. Your suggestion was to view the V en H signals of the faulty 7704A on another scope, with the other scope in XY-mode. The bright spot is on the

I looked back through this thread, and I don't know what the deal is here, so please forgive if I've missed something. In the OP, I think it was an issue about the readout distorting severely when the

Barry, The resistors are: R3439, R3442, R3493 and R3494. The the 510 ohm resistor, R3494 should be 1/2W. These are on the readout board. From what you said happened to the resistor, transistor and

Mark, I'm not sure which are the 2400 and 1500 ohm resistors. I don't see those values on the readout or the vertical amplifier board. As for the character height, I reduced R3468 to what I believe

Barry, The 2400 ohm and 1500 ohm resistors should be 1/2W. The former and one of the latter are in the upper left of the schematic and the 1500 ohm resistors to the two transistors to the outputs. I

Barry, Look at the crt circuit in the schematic. The diodes can/should be replaced with 1N4937 and I strongly suggest replacing R888 with a Vishay VR37 series 22meg resistor. That carbon will be out

I am clearly out of my league... How do I find the "intensity DC restorer" circuit? Thanks!

Disable the high voltage, unplug the CRT, certainly defocus the CRT, If there's a fuse in the HV supply, you might try removing that. The problem is (on a bright spot), the density of the electron

Harvey, Regrettably this is almost impossible without blanking the (otherwise extremely bright) central dot. It would require the use of one of the control signals (perhaps Z-axis Inhibit) in the

If the intensity control doesn?t work the blanking problem is a consequence of it. With a high degree of probability one or more diodes of the intensity DC restorer are leaky. Since testing it is

You might want to see if the unblanking pulses are doing what they're supposed to.? (or blanking pulses).? In some older scopes, there are diodes that have gone bad.? Do be careful, since they may

Interesting that you mention intensity. The intensity adjustment does nothing. I am troubleshooting that now. Barry

blanking problems.? You might want to check the CRT bias adjustments and similar voltages.? Turning down the intensity should make it vanish.? If not, then definitely blanking problems. Harvey

The following photos have been uploaded to the SC502 Trace Issues ( /g/TekScopes/album?id=293496 ) photo album of the [email protected] group. * IMG_2066.jpeg (

I posted a phot of my new problem. Someone with more experience than I will probably know! Please have a look. /g/TekScopes/album?id=293496 Thank You!

I solved the issue... Digged out my oldest Apple laptop, a 3400c, from about the same era than the AM700 and still working with MacOS 8. Once I formatted a floppy in that laptop the AM700 was

Is the 456 a typo in the table of contents? I think the issue you'll have is someone else recently done a very similar book and gave it away for free.

Silver solder is still made and some RoHS lead free may qualify. See AIM We designed the 500 kHz Metcal SP-200 solder station in 1990, constant current resonant supply. 20 sec warmup time,