EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: ra-ma on April 12, 2018, 06:16:43 pm
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Hello, I've been loooking for some time for a function generator. Last weekend I was lucky that an Exact Electronics Model 119 was on local eBay for sale. I was fast enough and got it.
Now I'm looking for some schematic and documentation of that generator. I couldn't find a lot of info about it. Can somebody point me into the right direction?
Here some pictures. As far as I can judge, it seems to be build very solid and clean.
(http://ra-ma.de/media/exact119/exact_119%20%281%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%282%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%283%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%284%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%285%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%286%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%287%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%288%29.jpg)
(http://ra-ma.de/media/exact119/exact_119%20%289%29.jpg)
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After some playing around I found some "spikes". Both at the high and low output. Is that normal or could that be caused by old e.g. leaky capacitors?
(http://ra-ma.de/media/exact119/Exact119_1.png)
(http://ra-ma.de/media/exact119/Exact119_2.png)
(http://ra-ma.de/media/exact119/Exact119_3.png)
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I recognize this layout. I cloned this model, or a very similar model, in around 1981. At that time it was already difficult to get some of the parts. Must be even more difficult now. The sine is generated from the triangle using a bunch of matched precision resistors and matched diodes. Matched diodes are marked with A, B, C and D.
I haven't used my clone since the early eighties but it should still be somewhere in the attic. I'll try to find it and the manual with schematics.
Btw, I do not remember any spikes like that, but at that time I only had a 20MHz oscilloscope.
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Hi ra-ma,
I do have a Exact function generator 121A, almost simular of your generator.
I am also searching for documentation or schematic.
Did you find your documentation ?
If so can you informe where you did find it please ?
Thanks ,
Victronics
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Found it!
https://casa.co.nz/Equipment/Instruments/Signal/119-Exact-Manual_78p.pdf
I recently bought a Exact 119 function generator and wanted the documentation aswell, so here it is for the next person looking for it.
The same site also has the documentation for the 517 & 519 model.
https://casa.co.nz/Equipment/Instruments/Signal/
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Good morning lads. New in this group.
Am also looking for an Exact model 529 signal generator manual and schematics.
I got mine from an ebay seller in the US. Apparently the unit had been used in universities somewhere in the US.
Unfortunately its Power supply has been damaged, and god knows what else with it.
Managed to find a technician that used to work with Exact. His name is Mark Keppinger, but he did not have any manuals for this model.
He was very helpful on assisting me converting it to 240v instead of 115v.
The transformer arrangements for re-wiring the device to different voltages was still fresh in his mind.
He also offered to do some tutoring for me to learn how to use it provided that I will later on publish all of the tutoring in a web page. I have agreed.
However due to the nature of my work (Professional Skipper and Sailing Instructor with RYA) was not able to carry on. The device was also badly damaged with usps while on transit here, nonetheless I managed to put it together, and later on fixed a major issue with the Power supply and a Motorola split power supply IC.
Its working now but I suspect there is still an issue somewhere, and yes all pots need a good spray again.
As I said earlier on am looking for schematics and user manual. If you guys ever come across anything that deals with Exact model 529, drop me a line. I also like to thank Ra-ma for sharing all the relevant manuals sources. At least I can study something which is relevant or close to the model I currently own. The parts replaced on model 529 power supply were MJE3055 and MC1468.
Thank you, many 73's de 5B4ZC
Thank you