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Products => Test Equipment => Topic started by: Dagon on March 22, 2013, 10:35:45 am

Title: TTI TG215 square waves not square
Post by: Dagon on March 22, 2013, 10:35:45 am
So I picked up a second hand TG215 from ebay for cheap as I'm going to be playing around with some filters.

Below 30Khz the output can best be described as 'wonky'. Take a look at the screenshots. Triangle waves don't appear to sufficiently pointy either though sine wave looks ok at first glance. Also the output doesn't seem very stable at any speed with the waves oscillating gently around the screen.

I've zero experience experience of function gens up to this point. Am i expecting to much at these speeds?

And while I'm bitching the symmetry knob is broken (so much for 'excellent condition') Dead pot maybe? I'm not see any voltage across it.
Title: Re: TTI TG215 square waves not square
Post by: Rerouter on March 22, 2013, 10:40:49 am
out of curiosity have you adjusted the compensation capacitor on your scope probe? it may not be causing the majority but may be adding to the 20Khz waveform,

as for not seeing any voltage across the symmetry pot, that doesn't sound like an open pot, more like a damaged component or supply rail in the device, as if it was open circuit it should have a voltage across it,
Title: Re: TTI TG215 square waves not square
Post by: Dagon on March 22, 2013, 10:56:14 am
No, I haven't. I'll tweak that this evening and see what happens.
Title: Re: TTI TG215 square waves not square
Post by: Rerouter on March 22, 2013, 11:10:24 am
use your scopes cal output, or a known working signal gen though, not the gen in question....
Title: Re: TTI TG215 square waves not square
Post by: Dagon on March 22, 2013, 11:49:18 am
Oh it'll be the cal output, there aren't any other function gens in my immediate vicinity, working or otherwise! I did adjust it when I got the scope but that was quite a while ago.

Title: Re: TTI TG215 square waves not square
Post by: Dagon on March 23, 2013, 12:44:08 pm
In case anyone every comes across anything similar it turns out the problem was a test lead

It took much messing around until it occurred to me to swap it out. Live and learn.