Gould Delta 9500A Oscilloscope Manual, other info?

Thread Starter


Joined Jul 28, 2013
Hi people,

Does anyone have a user manual, service manual, brochure, anything on Gould Delta 9500A? I'm mostly looking for a user manual, don't really need the other stuff, but it's nice to have. Any info is appreciated, it's a pretty rare scope. I've searched the net extensively, and the only thing I found is the manual for Classic 9000 series, which is similar, but really not the same (worse triggering, fewer options).

I scored a pretty decent Gould Delta 9500A scope for 150€ on Ebay (non-working). Really impressive spec: 500Mhz, 2GSPS, FFT, Hard drive, RS232 with usable commands, nice interface, pretty TFT screen. It was easy enough to fix: the 3.6V RAM backup battery was almost dead, but not quite, which corrupted the memory and the scope wouldn't boot. Holding the "Hold All" button on the scope while turning it on, then releasing and re-pressing it when it beeps, clears the memory and puts the scope into calibration mode. After calibration, it works OK (though with intermittent noise on CH1 which I have to examine; the heatsink on one of the CH1 chips fell off, I'm waiting for thermal adhesive to put it back on).

I had to glue together (reinforced with a metal splint) one of these "paddle" buttons, and one regular button was broken, so I 3D printed it. The files are here.

I plan to dump the 4 EPROMs on the board and upload them for anyone interested, when I get my programmer in the mail, and also dd the HDD into an image you can use (though I think that the HDD is just for saving traces; not sure, I don't hear it seeking). That should be helpful to anyone trying to fix one.

I've attached a pic if anyone is interested. Personally, I love the industrial design, shame it yellowed (and I don't care enough to retrobrite it).(