Two 3A9 Differential Amplifiers in a Tek 564B scope? - Page 1
Forum section: electronics / testgear

author: blatboy
author_rank: Unknown
timestamp: October 28, 2019, 03:12:48 am
content: Greetings. I was given a beautiful 564B scope about 20 years ago. It was my first scope and I never quite got it working.Now that 20 years have passed...and I started down the slippery slope of learning (some) electronics about 10 years ago, I'm now thinking that the reason I wasn't able to get it to "work" is that it had two differential amplifier plugins in it and it didn't have a time base plugin. Without a time base, that would not make it a traditional scope like what we're used to in basic electronics, yes?So, what would the use case be for a 564B with a pair of differential amplifiers? I understand the plugin on the left is for the vertical plates and the one on the right is for the horizontal... but without a time base, you wouldn't see a waveform, correct?Please pardon me if my question is basic/stupid/what have you. I'm just a dabbler ruining all your fun.

author: james_s
author_rank: Super Contributor
timestamp: October 28, 2019, 03:29:37 am
content: I'm not familiar with the 564B, but an oscilloscope with vertical and horizontal amplifiers and no timebase is a vector display.

author: 0culus
author_rank: Super Contributor
timestamp: October 28, 2019, 03:34:33 am
content: Yes, you basically have an X-Y display. Might be worth posting on the TekScopes mailing list on groups.io. Someone there likely will have the time base you need.

author: blatboy
author_rank: Unknown
timestamp: October 28, 2019, 03:41:51 am
content: Yeah... I thought it would be something like that.This is how it was when I got it... curious what sort of use that would be for someone... or maybe they just had those plugs and that's it? I was never told where the unit came from...

author: 0culus
author_rank: Super Contributor
timestamp: October 28, 2019, 04:01:49 am
content: Well, you can look at Lissajous patterns. Not terribly useful but prettyThey were more useful in the bad old days before oscilloscopes had trigger circuits. You can also build a curve tracer using an X-Y display. w2aew has a video about it.

author: blatboy
author_rank: Unknown
timestamp: October 28, 2019, 04:07:46 am
content: aaaah. cool. I'm subscribed to w2aew, so it's possible I've even already seen it. oy. hahaha. Thanks!

author: james_s
author_rank: Super Contributor
timestamp: October 28, 2019, 04:55:59 am
content: I've used the XY mode of my analog scope when working on vector arcade game boards.I looked up the 564B, I think one of those was the first scope I ever got to play with. It's an analog storage scope which is quite a rare beast these days, especially if the storage function still works. Apparently the CRT used in those is not particularly long lived.

author: blatboy
author_rank: Unknown
timestamp: October 28, 2019, 01:20:35 pm
content: Yeah, I'm not convinced completely, but I think the CRT might be kaput on it...

author: 0culus
author_rank: Super Contributor
timestamp: October 28, 2019, 01:41:24 pm
content: As james_s said, those storage CRTs aren't long lived. Try putting two sinusoids that are of slightly differing frequencies into the 'scope, one into each amplifier (I assume you can use them in a single ended fashion). You should see a Lissajous pattern.

author: blatboy
author_rank: Unknown
timestamp: October 28, 2019, 01:50:24 pm
content: I'll try that this week.