Hi,
This was my first multimeter. I got it from (then) West Germany nearly 30 years ago. It is branded "Universum" which was the brand of the German mail order retailer, Quelle, obviously rebadged. What is interesting is that it seems to be a quite high quality instrument. For a long time, I was unable to find anything on it, when I came upon this page
http://mrmodemhead.com/blog/yokogawa-7534-03-multimeter/. It features a very similar model, nearly identical inside and outside (except for the colour), made by Yokogawa. So I assume this one was also manufactured by them.
Unfortunately, I lost the user’s manual, so I don't have any specs, but here is what I know.
It is 4000 counts, has automatic and manual ranges. Measures mV DC, V AC/DC, A AC/DC (not truerms), resistance, diode, and continuity. One interesting mode is the ADP mode, which is basically a direct, high impedance (30Mohm) connection to the AD, provides 400mV range. It is useful to connect external instruments, like clamp meters or whatever.
It also has a bargraph display, measurement memory, hold (manual) and display illumination. So it is a pretty capable meter given its age.
Let’s have a look inside. The case is quite sturdy; the screws go into metal posts. Both halves of the case have shielding inside.
The input jacks are solid machined sockets. One big drawback is that the 10 amp input is not fused! But it did survive the stupid step of measuring mains voltage when the leads were plugged in the 10 amp range, the circuit breaker tripped before any damage! Well done. I’m not sure about the input protection, probably not suited to high power work. Obviously it predates the CAT ratings.
The mode selector switch is a real rotary switch, none of these PCB track switches. There is some flux residue on the switch and the backlight leads, looks like they are hand soldered.
There is a secondary board under the battery holder, and the LCD, but it is not possible to access them without desoldering stuff, so I don’t know what is on it.
As you see on the last picture, this is pretty much spot on. I did check other ranges and modes, they are also good. Given that this is nearly 30 years old meter, which has never been adjusted, I think It’s not bad at all.
The only problem I had is the fainting of the LCD, but it only required to clean the contacts to bring it back to life.
If you happen to have the specs on this or the history of this model, please post.