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  1. (*steve*)

    I think I'm starting a collection

    Here you go: Sorry about the bad lighting for some of these.
  2. (*steve*)

    Capacitor Knowledge Wanted

    Please post a photo of the capacitors. It's generally reasonable to assume that electrolytics need replacement in old equipment, but there are some capacitors which don't need replacing. Ceramic, film, and Mica capacitors will generally stand the test of time.
  3. (*steve*)

    I think I'm starting a collection

    I've heard about those Brooklyn Bridges. They might be old, originating from the stone age of bridge construction, but you need way too many cables, and the maintenance costs are astronomical.
  4. (*steve*)

    I think I'm starting a collection

    Well, I think it's the start of a collection of old bridges Whenever I tell my wife I've found another old bridge... She tells me to get over it. This one was hand delivered about 4 months ago to a relative in a town just a little too far away to quickly visit. We finally took a day trip...
  5. (*steve*)

    I think I'm starting a collection

    I have quite a few different ones now. Whenever I find another one my wife tells me to get over it...
  6. (*steve*)

    New project - 1967 oscilloscope restoration

    There are a few adjustments, but they seem to be trimmer capacitors. Also, the input is always capacitively coupled, so I don't see any reason why the coupling between the vertical amplifier and the differential delection plate driver isn't likewise capacitively coupled (but I haven't checked...
  7. (*steve*)

    Two relays in series with flyback diode.

    A shorted turn will probably change the turn on/turn off times. That may be important in this application. Also, what happens if a set of contacts on one relay Wells themselves together?
  8. (*steve*)

    Two relays in series with flyback diode.

    A single shorted turn on a dc relay isn't going to do a lot to the current passing through it or to it's operation.
  9. (*steve*)

    New project - 1967 oscilloscope restoration

    I was going to convert it to a component tester. However some tests I've done in X-Y mode concern me a little. I think there may still be some fault hiding in there. Changes in the gain of the vertical amplifier seem to have an effect on the position of the trace. This needs more...
  10. (*steve*)

    New project - 1967 oscilloscope restoration

    Damn, it seems to be working now :-( It seems like it was a switch contact issue because it went away after changing the vertical range a few times.
  11. (*steve*)

    New project - 1967 oscilloscope restoration

    Hmmmm, but sine and sawtooth doesn't look at all good I suspect a problem in the vertical amplifier.
  12. (*steve*)

    New project - 1967 oscilloscope restoration

    Well, it does show a square wave.
  13. (*steve*)

    New project - 1967 oscilloscope restoration

    I'm pretty happy with that I might grab a signal generator to see how well it works, but I really need to replace the line cord and put a plug on it before I do too much more. I'm pretty sure this isn't up to code
  14. (*steve*)

    New project - 1967 oscilloscope restoration

    Ok @73's de Edd, here's some voltages, all with respect to the chassis. The heater windings (pins 1 and 11) are at -515V and -513V respectively. Pin 11 is tied to pin 2 The cathode (pin 3) is around 7V more positive than the heater due to the voltage drop across the 100kΩ cathode resistor...
  15. (*steve*)

    isolating transformer and variac - what order?

    Not a straight through neutral, a straight through earth. However, as I suggested, a short from either side of the isolated mains to the chassis will render the isolation moot. Actually it's worse than that, because now you're not expecting to receive a shock through ground. This is the...
  16. (*steve*)

    isolating transformer and variac - what order?

    I have an isolating transformer and a variac. Would it be best to have the isolating transformer before or after the variac? My practice has been to put the isolating transformer before the variac. I can't see any real reason to favour one way over the other. On the other hand, my isolating...
  17. (*steve*)

    Capacitor testing

    It's generally easier to replace all potentially affected capacitors. Knowing which ones is why you pay someone :-) Post some photos of the power supply and we can identify them for you.
  18. (*steve*)

    New project - 1967 oscilloscope restoration

    @73's de Edd here is a look at the insides One of the screws is visible. What you can't see is the input socket and the line fuse. Note that the circuit breaker is also on the input to the autotransformer. In retrospect, it should probably have been in the output.
  19. (*steve*)

    New project - 1967 oscilloscope restoration

    It's hard to say. The best focus is certainly near the end of the pots travel. I'm uncertain if it gets a little worse at the very end. At a minimum, the best focus shouldn't be so close to one end. I will try that, but first I will check some voltages to make sure they're what I expect...
  20. (*steve*)

    PSU help please.

    I would try putting a small load on the power supply. A small vehicle lamp would suffice. If you get a higher output voltage then the adjustment pot will probably work to adjust it.
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