Any idea of what's this for?

[tozitom]

Hi forum,
Just got this instrument on my bench but cannot find any info on it! There's no make/model only what you see! My first thought was a audio distortion analyser, but seems not... When injecting 1khz input I can measure rms voltage (almost accurate), but no freq measurement on display, when switching to distortion I get freq counter ok (1.01/1.02 khz) and also I get an output with some shift from original depending on big coarse pot... On picture (1) is input (2) is output.

[EricJRW]

What does the back look like?

[tozitom]

Thanks for your reply. Back is nothing special, only 220v plug and sticker "made in italy"

[Grandchuck]

Sure looks like a distortion analyzer.  To use, one tunes the notch filter to null out the fundamental.  The fine tune makes it easier to get a good null.  What is left is THD and read on the meter.  The controls seem to support that.  Could be fun and instructive to play around with.  Nowadays, THD and FFT software that runs on sound cards in computers has kind of taken over.

[Old Printer]

Like Dave says, take it apart, at least to look inside for some sort of manufacture info. It might have been intended for sale under a third party label, hence no exterior markings, but somewhere that should be some clues. Interesting.