Broken Signal Generator

[cksa]

http://cgi.ebay.com.au/HP-SIGNAL-FUNCTION-GENERATOR-/170497804922?cmd=ViewItem&pt=AU_B_I_Electrical_Test_Equipment&hash=item27b2760a7a#ht_500wt_1117

What do you reckon? Should I snap it up and hope I will be able to suss out the problem? Worth it?

[cybergibbons]

The service manual is available, but these really are beasts inside - really really complex.

That said, if it is responding to user inputs, I would say you have a fair chance. If you don't have a scope and decent meter though, I'd get them first before taking something on like this.

It's quite a high-end signal generator, personally I wouldn't need most of the features and would prefer a new, but more simple, generator.

[cybergibbons]

http://www.to-way.com/teqman/HP/8165A/HP%208165A%20Service.pdf

[cksa]

I do have a scope (Rigol) and meters. Of course there's no way i need all of the features anyway , but other signal generators on ebay all seem to be more expensive (even the basic ones)!

[alm]

I would be tempted if I had the room and it went fairly cheap (almost five days to go, so the final bid might be much higher). I don't think it contains many custom parts, so in theory it should be repairable. From the description, the digital stuff seems ok, but the defect seems somewhere in the analog section (eg. frequency generation or output amplifier). It could be something really simple like a shorted tantalum capacitor, or something harder like a subtle problem with a hard-to-find op-amp in a loop. You have to consider it a gamble, you might win (replace a $0.10 tant and be finished in half an hour) or lose and never be able to fix it.

I wouldn't be worried about buying too much function generator (for a reasonable price), better to grow into something than to outgrow it.

[tecman]

Manuals are available for download on agilent's site.  Most of this equipment is very robust.  Circuitry is usually fairly easy to troubleshoot, and most failures are a simple cap failure or similar.  For the price I would go for it.

paul