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  1. (*steve*)

    Heathkit Condenser Checker

    I think I'm almost done! After changing the voltage divider resistors, I'm getting almost exactly 100% of the marked voltages. They rise to about 107% when switched to the electrolytic setting. If there's anything else to do, it's probably regulating the high voltage supply.
  2. (*steve*)

    Hello and How do I check the voltage of this SMPS?

    You need a load. I'm not sure what the rates load is for this supply, but if it exceeds an amp it so then a 100W light bulb may be an acceptable load (don't expect it to light brightly (it may just glow a little red). Measure the voltage on both the AC and DC ranged of your multimeter, and tell...
  3. (*steve*)

    Hello and How do I check the voltage of this SMPS?

    I would 1) check the output caps for high esr, 2) check for shorted rectifiers, 3) remove it from its load, possibly applying a smaller known load to it and then see how it goes.
  4. (*steve*)

    Heathkit Condenser Checker

    Here's an update schematic. The changes I've made are indicated in red. In the voltage doubler the diodes are 2kV 0.5A, the capacitors are 400V 6.8uF, and the bleed resistors are 1.2M. The 2.2k resistor in series with the high voltage to the 1629 is to allow current measurements. The...
  5. (*steve*)

    Heathkit Condenser Checker

    I did a bit of fiddling after reading up on these tubes. The idea of using a higher target voltage is also to reduce the current in the tube. The only practical way of doing this is to reduce the heater voltage to reduce the emissivity of the cathode. After some fiddling and various...
  6. (*steve*)

    Heathkit Condenser Checker

    Finally I have had some time to do stuff... I have found that the autotransformer seems to put out a little lower voltage than I expected. This causes all sorts of problems related to the various unregulated voltage rails. This causes the voltage for the magic eye tube to fall to as low as...
  7. (*steve*)

    Oscilloscopes bandwith and sampling rate (digital)

    Keysight are a reliable source for technical information like this. Alternatives could include Tektronix and Rohde & Schwarz. Any manufacturer that produces scopes with bandwidths in the 10's of GHz or higher (not sample rate) is very likely to know their stuff.
  8. (*steve*)

    Help with Burned out 3000 watt inverter

    Those conditions are when the current from the battery will be highest. Are you sure the devices you're replacing can handle the expected current? If it fails after a while it could also be related to excess power dissipation caused by a higher on resistance.
  9. (*steve*)

    solder paste and flux

    Firstly, those are flux, not solder paste. Secondly, these are designed to be placed inside a mechanical or (more frequently) pneumatic dispenser. The connection on the end is a standard luer-lock connector, the same as many normal syringes. It is possible to get luer-lock to luer-lock...
  10. (*steve*)

    I think I'm starting a collection

    I have not had a chance so far to check it in any way other than to gently caress its controls.
  11. (*steve*)

    I think I'm starting a collection

    I couldn't help myself. These were just too pretty :-) A Leeds & Northrup Wheatstone bridge. And a Leeds & Northrup type K-4 Potentiometer. The potentiometer is a really marvelous piece of hardware.
  12. (*steve*)

    Heathkit Condenser Checker

    240V mod completed. I've moved the filter caps to keep them away from the incoming mains, and the chassis is now earthed. Rather than having tag strips with mains voltage on them, all the primary side wiring is taken directly to the fuse, switch, etc and the exposed connections are covered...
  13. (*steve*)

    Heathkit Condenser Checker

    It's a cold, windy, and rainy day, so I'm working inside and looking nervously at the weather radar for the forecast 100km/h winds and heavy rain. So here's the one remaining foot the case had. Replaced with some adhesive rubber feet. The old remaining foot was hard and ready to fall...
  14. (*steve*)

    Heathkit Condenser Checker

    Yeah, I was hoping mine was one of them, but sadly it isn't.
  15. (*steve*)

    Heathkit Condenser Checker

    A small step forward. Creating clearance for the power socket. The hole is a bit rough But it does the job. And the mounting holes for the back panel line up nicely. One of the problems with the original case was that it was kinda tricky to line up those holes. With the socket there...
  16. (*steve*)

    LED or CFL flickering with motion sensor in circuit

    It is likely that either the reduced current consumption of the LED panel, or the unusual power factor of some LED drivers is causing your problem. Getting a motion sensor that explicitly stated it is suitable for LED bulbs may help, but it's not certain.
  17. (*steve*)

    Heathkit Condenser Checker

    I think the device was dropped before I got it. The front panel is actually bent a little. I straightened out out a bit, but clearly not quite enough.
  18. (*steve*)

    Heathkit Condenser Checker

    Things still moving slowly. But I have replaced the old terminal posts. I straightened out the panel, but the post to the right still doesn't sit straight. I might have to apply some delicate persuasion to it.
  19. (*steve*)

    Heathkit Condenser Checker

    Hmmm, this looks better No need for the transistor to carry the discharge current.
  20. (*steve*)

    Heathkit Condenser Checker

    In parallel with other mods, I'm also converting this to 240V and earthing the chassis. I'm replacing the mains cord with an IEC connector, and fitting a small autotransformer. First step is to nibble out the appropriate size hole Then clean it up. And it kinda fits But I have to...
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