Bullet VM30 combo, GDR from 1990

Found in an old VEB Kombinat Mikroelektronik databook:

B080D = TL080 B081D = TL081 B082D = TL082 B761D = TAA761 V4007D = CD4007UBE

Best regards

Piotr

markings

Thanks for that, I'd only assumed there was no use for 6 off CMOS inverter packs, assuming they were more likely to be quad opamp packs.

Do you know why there are all thes +digit numbers on the ICs transistors and electrolytics ? the 2 main TO3 output Tesla devices are marked KD607 but also X69321

thes +digit

should read

these X + digit

No idea about the electrolytics. On the semiconductors, it's the marking for production month and year (but I don't have the code handy).

The KD607 is a Czech npn power transistor, 10 A, 80 V, 70 W, designed for AF power amps.

and

I only have one German data book , ECA from 1987 and it does not list the final uncertainty. An E-line size or varicap type package of a diode marked 32 VV or 32 YV, 32 volt zener ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Any chance to take a photo? My guess is it's an SAY32 which is a simple silicon small-signal diode.

with a 2.5mm nut for scale

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

"N_Cook" schrieb:

Yes, it's an SAY32. The YV is -- again -- the datecode only. The SAY is left off from the marking, because it's been obvious, so only the

I uploaded the respective databook page to:

It's a SAY32

Some more data sheets for components from GDR:

KD607:

XL

Certainly the right package. I've now powered up and the 15 marked ones are the zeners for setting the

The siting of the ones marked 32 maybe for overvoltage sensing , but not normally in service.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

second attempt

Certainly the right package. I've now powered up and the 15 marked ones are the zeners for setting the

The siting of the ones marked 32 maybe for overvoltage sensing , but not normally in service.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

"N_Cook" schrieb:

(Why? Your first attempt worked pretty well.)

Yes, the Zener diodes were just marked with the voltage in the first row, and the production date in the second row. The prefix SZX 21/ was implied. Kinda hard to distinguish them from the plain diodes marked 30/32/40/42, but as the maximal voltage for the Zeners was an SZX 21/24, there was just no collision in the numbering.

Repaired now, but for the archives there is a safety issue with these amps. The earth bond wire to the amp chassis is fine but the bond to the front panel metal is very poor, just a brass rivet to the phenolic of the pcb, of a few ohms drop over the years. Needs redoing to the metalwork properly.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on