Can't find a schematic! Help!

[calexanian]

I can't find a schematic for a Beckman Industrial FG3B. This is one of those sweep generators that popped up with a dozen different names on it in the early 90's. Nowhere can I find a schematic for one. The output amp died and I have been going under the assumption it is a basic complimentary pair amplifier but I just cant make any headway on the thing. Its not worth sending to somebody to have it fixed, but its simple enough to do on my own, provided I had a schematic.

HELP!!   

[retiredcaps]

Beckman doesn't make a lot of their own stuff.  Search for Wavetek FG3B and there is a

https://www.manualsdrive.com/document.php?lang=en&iddocument=D4s2z39ace

schematic, but it costs 29 Euro.

Off to look for a free version for you.

[calexanian]

Thanks! 29 euro, is a bit much. Wavetek has it, exact same model number as a matter of fact.

[calexanian]

I fixed it anyways. It was not a traditional complementary circuit. It was actually interestingly enough kind of a cheater circuit I have used a number of times. They built a discrete op amp type circuit with a 47 ohm resistor to the output jack and the two output transistors basses on the amp side of that resistor and the emitters on the load side and the feedback from there back to the input of the op amp. Kinda weak sauce for a $400 piece of equipment. Anyways the circuit already has some collector blow out resistors so I tacked in a 3904 and a 3906 respectively and got my output amplitude back. I just now put in MJE15034 and 35's on heat sinks and everything looks good. Most of the holes are not even plated through on this thing! Talk about crap! 

[retiredcaps]

Well, I'm glad you got it fixed and documented the repair.  I spent the last 1 hour looking for the schematic (even for the FG2, older model), but came up empty.   

How about a couple of pictures of the insides?

[calexanian]

I already buttoned it up! If I get a chance I will pull it open again and take some pictures. You will not be impressed. Its a double sided board, but many of the holes are not plated through. late 80's early 90's test gear at its most mediocre. all through hole jelly bead CMOS and logic. Cheapest choice analog section. Etc etc.