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Luca, Going from the first in the schematics to last: A1- 100mfd 25V (order 10) 647-ULD1E101MED1TD (14) 47mfd 25V (order 41 or more) 647-ULD1E470MDD1TD (UHE series will work) (2) 220mfd 16V

Good point. Perhaps the noise is still there but not visible without x10. Ozan

If the Delayed Sweep switch is not in EXT HORIZ then the x10 mag will not engage. It's when the X amp is in magnified mode that he sees the noise.

Thanks Mark. I just educated myself on the RIFA capacitors watching Dave's EEVblog video. I will replace mine. It would be helpful if you can provide a list of parts that need to be replaced. Thanks

Thanks for the tips! I wonder why they design the start-up circuit this way rather than using a separate always-auxiliary supporting power supply. One reason may be to save one transformer. The other

Pasternack is also quite a price gouger. I have found identical components from other vendors at considerably lower prices. Why pay $75.00 for a one foot N(M) to N(M) cable with standard coax? Greg

The mechanism would be: HV supply feeding into F937 comes from the same secondary winding of the transformer as +12V. You can see the connection across C1142 in sheet <17>. A possibility is one of the

Looking at the X plate signal will give a clue to what's going on and reduce the time spent looking for the culprit. In the mode you're using, the X signal is travelling through the B trigger gen

I do have a second scope. I could give that a try. I looked at C937 yesterday, tested good with ESR meter. Not familiar with the term "EHT" but I have back cover on, the shield on the HV section is

OK, well that explains why the waveforms at TP485 & TP494 look right but the voltages were "wrong". The schematic doesn't really make that clear about how to measure that. Was under impression that

Do you have second scope? if so, you can identify the nature of the problem by putting the 453 into X-Y mode with your quarter-inch "dot", then looking at the voltage on the X plates with the second

On Thu, Apr 21, 2022 at 06:41 PM, Ozan wrote: > > On Tue, Apr 5, 2022 at 07:18 AM, diyguitarist wrote: > > > I did notice that if I put the Horizontal > > Display switch between DELAYED SWEEP (B) and

For what it’s worth, the Fluke 540B AC-DC Thermal Transfer Standard originally used a mercury cell. In 1993, a mod was published for Lithium plus a 317 regulator. They could get away with this

Thanks for doing that. I looked at that whole area and I didn't find any bad components. I have also suspected that maybe C485 (3.3uF) was bad. It tests as open with ESR meter and ha a very funny

Hi Greg, Yes, unfortunately the ER1400 is rather difficult to deal with outside the chassis or without the GPIB option. Programmers to read and write it were far and few between, and virtually

Luca, Since R1071 is burning, C1071 is bad. This is one of those RIFAs that needs to be changed out with new. This type can be 630V type film. The two that need to be an X1 or X2 type are C1016 and

1. Those voltages are correct if you measure when the sweep is trigggered. They revert to the schematic values with a free-runing trace. 2. On my 453 (c 1970) the ripple & noise on the +12V and -12V

Due to start-up circuit and loopbacks, difficult to debug Use isolation transformers on mains, following PSU flowchart Check the power transistors, rectifiers Any blown up power semiconductor will

Hi Tek Group, I have a Tek 2465 that has power supply issues. I have followed the instructions from the Tek Service Manual, and found that the INVERTER DRIVE portion of the inverter board is

Pat; it would be helpful if you could identify which version of the 453 you have. Then, measure & post some DC voltages thro the X amp with the shift control centred. I have spares for these scopes.