When doing that, make very sure your work area is clean of any ferromagnetic debris (including flakes of stripped screws etc). If any at all gets pulled into the gap in the movement, you are looking at a difficult repair with a good chance of ruining the movement.
@15:48 I prefer using european colours - brown and blue - when redoing mains circuitry. If it's in its own harness, it's very intuitive to european eyes to mean "mains voltage here!". Also, if you run out of these wires, just cut apart a length of old (not so old that you get asbestos fibres) mains cord... @16:30 you know you did extensive recapping when there's more dud caps than cigarettes in your ashtray :)
I have the linear version of this... can confirm that it weighs as much as your 7000 series scope! Has the big meters, too! It even comes with a stout handle you can tie to someone you don't like before you drop them overboard.
Simple linear supplies that are 20 to 30 amps capable (usually 3-24V, no adjustable current limit but can be current limited precisely with an electronic load :) - and yes, heavy AF even if definitely not built to HP standards) that were probably designed originally to supply questionable CB/HAM linear power amplifiers turn up cheap from time to time...
I thought I would let you know I purchased a LARGE surplus of Tek and HP parts. I have hundreds of NOS POTS, transistors high precision resistors .1% and so much more stuff. I happy to help out should you need and parts for your channel repairs.
Tt is not just stuck however after disassembly of the meter it looks like one of the bonding wires is broken. The movement is ok. I will shoot some more and see if there is a fix to the meter.
@@ZenwizardStudios Good to hear. Came to the comments to say I'd had a bad connection between the terminal and wire inside the voltmeter on my HP6825A. The meter would seem to get stuck; tapping it or turning the voltage up would cause it to start working.
hmm 1ma meter should not be too hard to find, but getting one the right dimensions will be a search. Maybe you will have to get you tin nipper out o make the hole bigger ;) I have a round one that will work but that would look really ugly ;)
Or 100uA with a shunt - but there are subtle traps in both cases, the surrounding circuitry might rely on a certain meter coil resistance (and changing it could in certain edge cases introduce surprise temperature dependencies which could actually be relevant in a power supply or other device that can get quite warm internally)....
I've gotten to never expect bad meter when looking at old units. That's good because they are definitely sealed up to protect their precision. I second the above suggestion to attempt diagnosing the meter's issue.
One time I had a VU meter open, it was just a fatigued wire inside it, a touch of solder fixed it. Open it up and look.
When doing that, make very sure your work area is clean of any ferromagnetic debris (including flakes of stripped screws etc). If any at all gets pulled into the gap in the movement, you are looking at a difficult repair with a good chance of ruining the movement.
@15:48 I prefer using european colours - brown and blue - when redoing mains circuitry. If it's in its own harness, it's very intuitive to european eyes to mean "mains voltage here!". Also, if you run out of these wires, just cut apart a length of old (not so old that you get asbestos fibres) mains cord... @16:30 you know you did extensive recapping when there's more dud caps than cigarettes in your ashtray :)
@6:20 those large white caps probably need replacing too, I have seen those types leaking.
Replace if found always is a good one!😁
I have the linear version of this... can confirm that it weighs as much as your 7000 series scope! Has the big meters, too!
It even comes with a stout handle you can tie to someone you don't like before you drop them overboard.
I would not mind a few of the linear versions just need to build the shelving strong enough.
@@ZenwizardStudios Yes..... yes you would. I groan every time I have to move mine!!! 🤣 They are kind of loud, though.
Simple linear supplies that are 20 to 30 amps capable (usually 3-24V, no adjustable current limit but can be current limited precisely with an electronic load :) - and yes, heavy AF even if definitely not built to HP standards) that were probably designed originally to supply questionable CB/HAM linear power amplifiers turn up cheap from time to time...
4.7k pot and a parallel trimmer? Or... possible to disassemble the original pot and wire into it?
I thought I would let you know I purchased a LARGE surplus of Tek and HP parts. I have hundreds of NOS POTS, transistors high precision resistors .1% and so much more stuff. I happy to help out should you need and parts for your channel repairs.
If this offer is open to others, how do we get in touch? :D
@20:00 are you sure the meter isn't just stuck?
Tt is not just stuck however after disassembly of the meter it looks like one of the bonding wires is broken. The movement is ok. I will shoot some more and see if there is a fix to the meter.
@@ZenwizardStudios Good to hear. Came to the comments to say I'd had a bad connection between the terminal and wire inside the voltmeter on my HP6825A. The meter would seem to get stuck; tapping it or turning the voltage up would cause it to start working.
If you would share the dimensions of the opening for the meter, myself and others could check their parts and see if they have an equivalent.
There will be a part 2 to work on the meter.
hmm 1ma meter should not be too hard to find, but getting one the right dimensions will be a search. Maybe you will have to get you tin nipper out o make the hole bigger ;) I have a round one that will work but that would look really ugly ;)
Or 100uA with a shunt - but there are subtle traps in both cases, the surrounding circuitry might rely on a certain meter coil resistance (and changing it could in certain edge cases introduce surprise temperature dependencies which could actually be relevant in a power supply or other device that can get quite warm internally)....
@@splitprissm9339 Hmm never simple is it ;)
it looks like you have plenty of room to go with digital meters
I've gotten to never expect bad meter when looking at old units. That's good because they are definitely sealed up to protect their precision.
I second the above suggestion to attempt diagnosing the meter's issue.