Gould Advance Signal Generator J4 manual or information? - Page 1
Forum section: electronics / testgear

author: mpuq
author_rank: Newbie
timestamp: October 21, 2017, 02:05:06 pm
content: Hi everybody.Does anyone have any information on this unit, I just picked one up and paid €5 for it.I could not find any information on this. Serial No. on the backplate is 001 72, so I guess this is from the year 72.There is also a maintenance badge from 1978. Power cord is broken, so I cannot test it before replacing it,I guess it could be a good idea to also check power supply caps?Is this a keeper or worth any effort? I guess I could use this to help measuring audio filters and or speaker elements.Then again I'm going to buy an oscilloscope with an internal signal generator in the future..Thank you in advance for any help.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 21, 2017, 02:34:29 pm
content: Hi,I used to use a signal generator like that when I was at university, they were new thenTry search for J3B. It is a similar product and probably very similar inside.Link:http://www.vespalabs.org/lab-notebook/shelved-till-later/gould-j3b-signal-generatorThe company started as Advance and was acquired by Gould. Products were branded as Advance, Gould Advance and then Gould.The circuit is based a round a thermistor stabilized Wein Bridge Oscillator if I remember correctly.I believe that there is an output transformer.These are reasonably good.You probably just have to clean the switches.Jay_Diddy_B

author: nfmax
author_rank: Super Contributor
timestamp: October 22, 2017, 08:01:37 am
content: I have a Gould J3B and a copy of the manual, which includes a circuit diagram and theory of operation as well as servicing instructions. PM me if you would like me to scan it for you. It's not exactly a complicated unit! The most useful feature of these instruments is they can drive 1W or so into a low impedance load like a loudspeaker. I haven't switched mine on in years though, I don't know if it still works...

author: nfmax
author_rank: Super Contributor
timestamp: October 31, 2017, 11:12:31 pm
content: I don't know how @mpuq got on with his J4, but after sending a copy of the manual, I was inspired to check my old J3B out. It probably hasn't been turned on in the last 8 years - but it works, as far as I can tell, perfectly. Frequency is within about 1% of the dial indication, the level meter reads about 2 to 3% low, but it works on all ranges, 10Hz to 100kHz, sine and square wave (0 to 5V). These things have a transformer-coupled balanced output. Using the scope between centre tap and one hot terminal, I see half the full signal swing, which is 30V RMS - quite a bit more than most other LF generators provide. This is in addition to the 3V RMS low impedance output. I remember why I hung on to it now!

author: mpuq
author_rank: Newbie
timestamp: May 05, 2022, 11:53:37 am
content: I'm sorry for replying for this now, almost five years later, but life got in the way. J4 works at least for the sinusoidal part. I cannot get a signal from the square wave output, not sure what's wrong with that, but I think I'll figure it out. The dial is not spot on with the frequencies, maybe someone has been heavy handed with it. I managed to get 10Hz-105kHz output just fine and at the moment I'll dial it to the correct frequency with oscilloscope.