On Tue, 15 Sep 2020 15:13:30 -0700 (PDT), wrote:

snip

Quite. Even rock bottom £2 multimeters have specs. No specs makes the readings fairly meaningless.

Depending on what you use the PSU for.

All my PSU's so far have been linear and with analogue displays and
controls and so the setting accuracy was really down to the analogue
meter and the granularity of the control knobs.

Two Weirs are built like an old skool radio with lots or wires and a
fairly large PCB and given most of the stuff on there is likely to be
good (or easily replaced), I was wondering if I couldn't take the most
faulty one and 'upgrade' it with an LM338 or similar?

I could replace the analogue meter with two digital ones (or a dual
one) but I could stick with the analogue meters to start with as
that's less to do.

The only thing is it's currently able to be split rail or 0-30 so I'd
probably lose the spilt bit (not sure I've ever used it).

Ideally I'd like a kit PCB with all the components on that aren't
already in the Weir and start from that. At least I could fault find
it if / when it goes wrong. ;-)

I have seen one that suggests the LM338 can be 0-30V and 5A so I could
limit the current to 4A to match the existing meter and allow it to
run cooler (it has a large passive heatsink across the back).

Cheers, T i m

p.s. I think I'll still go for one of the basic SM PSU's and I'm sure
it would be fine for most my needs and I've used one before.