Issues with newly acquired Tektronix T932A - Page 1
Forum section: electronics / testgear

author: dzarren
author_rank: Contributor
timestamp: January 29, 2017, 11:45:55 pm
content: Hi there! First post here, but I've been following the forum and the eevblog videos for many years now.I recently acquired some equipment. I've got a bunch of variable power supplies, and a Khron Hite 4200 oscillator.My favorite thing of the bunch is the Tektronix T932A scope i got. It's bandwidth is 35MHz.Anyway, I'm having some issues with the scope that I don't know how to remedy, or trouble shoot.So I've connected the scope up to the oscillator, and both channels on the scope seem to have no problem.The oscillator has two outputs, one called output, and the other is 1 volt. Now is this 1 volt peak to peak?When I feed that signal into either channel 1 or two, i get a signal that is 1 volt peak to peak.But when I put the scope in DC mode (on either channel 1 or 2, they both behave the same)and try to measure a DC voltage, it seems to be off my a factor of 2.I tested my variable power supplies with a few multimeters, and they seem to be working almost spot on the analog readings they give out.But when I connect the Powersupplies, (any of the 3 i have) to the scope and set them to 3 volts, the reading goes up not even 1.5 divisions (if i have it on 1V per division)and if i set it to 5 volts on the supply, the scope barely makes it to 2 divisions. I thought maybe it's just out by some factor?But from the oscillator i have, when I put in the "1 Volt" output, it shows on the scope almost exactly 1 volt peak to peak.So is the signal from the oscillator 1 volt peak to peak, or is it generally something else? Sorry I'm just a beginner.The other problem is that I cannot get the scope to display both channels IF and only IF one is AC and the other is DC.If both signals are DC, it displays clean, and if both signals are AC, it also displays clean.But if one is AC and the other is DC, regardless of which is ch1 and which is ch2, the scope flashes like crazy and cant trigger properly and it just seems impossible to get a clean display. What might be causing this?Also, for anyone that has this scope, how do you activate the 10x volts /division setting? It shows on the front panel that this is an option, and the knobs pull out slightly, but it doesn't do anything to the reading.Another tiny problem is that when I'm reading down at around 3mV, there's this faint ghost signal that is exactly out of phase with the real signal that shows up on the display.Thank you for reading!

author: tggzzz
author_rank: Super Contributor
timestamp: January 29, 2017, 11:58:49 pm
content: What is the trigger source? Have you tried "ch1"?The *10 indicator is only selected when you use a *10 probe which can tell the scope it is *10. Not all probes can do that; look for a contact in the probe.I suggest you try and find the manuals for your equipment!N.B. I'm not familiar with that specific scope, only with scopes in general.

author: dzarren
author_rank: Contributor
timestamp: January 30, 2017, 05:23:56 am
content: Yeah, its got a trigger option called ch1/ch2, so I've been using that, and seems to work great if both are dc, both are ac, or if I'm just using one channel at a time.There aren't any scans of the manual online, but there is some guy on ebay selling scanned versions on a CD rom, so I'll probably get one of those if i can find one just floating around the interwebs.

author: JPortici
author_rank: Super Contributor
timestamp: January 30, 2017, 06:48:29 am
content: http://w140.com/tekwiki/wiki/T932