Salvaging some multi-turn Beckman Helipot potentiometers
Bought a 12V/10A brick power supply from eBay. Something rattled inside so I had to open it! Inside I found something funny, a second IEC connector. The output side is similar, the original wires chopped off and new ones soldered to the underside (almost shorted!). I guess the power supply is refurbished from something else. The caps are Rubycons though!
Salvaging some multi-turn Beckman Helipot potentiometers
Nice, I have one of those old helipots. Still works good, after several decades.
Ouch terrible, earth connection not connected?
Ouch terrible, earth connection not connected?
What would you connect it to? The casing is completely made of plastic and the original PSU obviously isn't earth referenced.
McBryce.
Ouch terrible, earth connection not connected?
What would you connect it to? The casing is completely made of plastic and the original PSU obviously isn't earth referenced.
McBryce.
Difficult to see but picture one shows a green wire and large metal plate so
Ouch terrible, earth connection not connected?
What would you connect it to? The casing is completely made of plastic and the original PSU obviously isn't earth referenced.
McBryce.
Difficult to see but picture one shows a green wire and large metal plate so
It's a PCB mounted socket (otherwise why would they have needed to add the second socket at all?), so it does have wires. That could be just some random bridge.
McBryce.
The earth pin of the outer connector is indeed not connected to the inner brick. The metal casing of the brick is earthed, and a quick continuity test from the output ground to mains earth shows a connection. I haven't tested it for noise but the output voltage is stable from 0 to 7 A. I don't know how the missing earth connection will affect the circuit but I'll connect it when I replace the connectors.
Any laptops I have here (including the one I'm using at the moment) doesn't have an earth connection at all. All two pin IEC Plugs.
McBryce.
Paid $150 for an HP 34401A. The seller then threw in a bunch of nice cables, then offered me a free PM6303 LCR meter, which of course I accepted.
Wow, I need a $160 34401a!
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Heathkit EU-30A decade resistor.
I got a 1T 10% resistor from ebay. It checks out on the GR 1862B and the Keithley 610B, though with the latter, my measurement setup leaves a lot to be desired -- slow to settle down and if I get within a couple feet of it it upsets the reading significantly!
I ordered some time ago some serious HP "Iron" in an old 8662A - she is a very heavy unit with a plastic power switch down low and quite prominent , I needn't have worried - it was one of the best boxing for transport I have ever received.
Bubble wrapped, taped, foam peanuts with block polystyrene around and then double boxed with more polystyrene and peanuts in between the boxes!
Amazing job from "e-liquidators" eBay seller
. (no - association other than happy customer)
Here she is with about half the peanuts removed.
Thanks for the good packing report. Always beneficial to know who the good sellers are.
Nice packing job they did. I wish all vendors would care as much. Amazon is notorious for not giving a damn. I ordered a ARB on board air compressor for $500 bucks from them a couple of years ago and they sent it in the retail box. No packing, no nothing. Not even tape on it and this thing was around 30lbs. The box arrived, and nothing else. They sent another, and it arrived with a ripped up box and no wiring, papers, or any thing else. So, they sent another and it arrived smashed. Then I complained loud enough that they finally put it in a shipping box and it arrived fine. $1500 dollars of destroyed waste. Go figure.
Yep! It makes ya wanna cry. What was in the box?
Ha! Fortunately, IME Digikey packs things well -wrapped in plenty of their waffly paper padding and in box much larger than the shipped product. But still...
Amazing what's available on online shop these days...
Bought this one to complete the set after I bought the 24PT (based on Picasso), also because I suddenly realized Picasso doesn't handle floating point
Ordered a medical isolation transformer from Ebay.
Toroid ISB060W
What are you going to do with it?
First make sure it is fully isolated and modify it if it isn't. Then use it for the occasional repair of computer power supplies, and anything else that I like to repair. I have 4 shelf tube type AM radios that I inherited that act rather funky and I would like to get them working decently. There is also a old tube hi-fi (cabinet type) that my father in law is giving me. It is in beautiful shape and I would like to make sure it works well, sell it, and give him the proceeds. He's well retired and needs the money more than we do. IF I have to do any diagnostics on those units with power applied, it will be worth it as long as I remember to keep one hand in my pocket. I can't afford a differential probe right now so it is the best I can do.
Haven't worked on a tube set in decades but I'm reading and brushing up on it.
Ordered a medical isolation transformer from Ebay.
Toroid ISB060W
What makes this a "medical" insulation transformer?
It looks like it can be switched from 115 to 230V, right?
Please show a picture from the inside.
Thanks.
Looking forward to your internal pictures. This seems to be a nice insulation transformer.
I bought some dead batteries from 1986 or earlier (that's when Energizer was no longer owned by Union Carbide). No leaks! Also a Simpson 255 that they were inside of -- may need slight calibration and exterior cleaning but is otherwise fine.