Need Help Translating Tektronix 2465A Controls to 2247A Controls - Page 1
Forum section: electronics / beginners

author: Electro Fan
author_rank: Super Contributor
timestamp: May 25, 2013, 07:42:38 am
content: Hi,I was wondering if someone here might be up for doing some scope coaching.I saw the attached video using a Tektronix 2465A:I’d like to duplicate what is being demonstrated in the video. I’m not sure exactly what is feeding the 2 channels in the video but I have a function generator and a Tektronix 2247A.Most of the 2247A controls are similar to the controls on the 2465A but they are not identical.As per the video, I’m trying to figure out how to make the 80kHz sine wave gated by the 2kHz square wave using the delayed sweep.I can figure out how to use the function generator to feed either a 80kHz sine wave and a 2kHz square wave into the 2247A, no problem. How to get those two signals from my one channel function generator to the scope at the same time might be a problem. (I have a t-adpater I can use to send two of the same signals (80kHz or 2kHz or any other frequency 0 to 20MHz) from the function generator to the scope (with one copy of the signal going into channel 1 and another copy of the signal going into channel 2) but they would both have to be either a sine wave or a square wave.There is a second output on the front of the function generator (for TTL/CMOS) which would enable me to vary the voltage output between each of 2 channels, but I think they would still be subject to same frequency and wave pattern settings.Another challenge is that my 2247A doesn’t have the pullable SEC/DIV sweep knob (like on the 2465A) but maybe there is another way to accomplish the same thing? I’d like to figure out how to do the gating and magnification process as shown in the video. I have a different set of controls buried deeper in one of the menus on the 2247A that initiates the highlighting function. I don’t have the delta t buttons as shown on the 22465A, but using the time button on the 2247A I can invoke time measurement cursors and I have two other knobs (the cursors/time position knobs) that control the width and location of the highlights. I do have a B run after trigger.Mostly, I’d like to get the same 4 waveforms on my screen – but I’m not sure if I’m feeding the right signals to channel 1 and channel 2 or if I’m not using the controls properly.Any chance someone would be up for walking me through how to duplicate the video demo but using the 2247A? (I’ve included a screen shot of both scopes to make the controls as visible as possible. I’ve also included a photo of the function generator I'm using in case that helps.) Thanks!

author: w2aew
author_rank: Super Contributor
timestamp: May 27, 2013, 03:03:33 am
content: I haven't used a 2247, but judging from the photo, it appears that it should be able to come close to what the 2465 can do. One thing that it looks like it may lack is the ability to show just the intensified display of the delayed B timebase overlaid on the waveform. But you should be able to show both the slower A timebase simultaneously with the expanded and delayed B timebase, likely with the intensified area on the A sweep indicating where the B sweep is occuring. To do this, you would hit the Mode button that is just above the TRACE SEP control, and select the ALT mode. This should allow you to alternate between the A and B sweeps. I would guess that the SEC/DIV knob will now adjust the B sweep time, and the DELAY control (above the 10x switch) will adjust the horizontal delay of the B sweep. The TRACE SEP control will adjust the offset between the A sweep and the delayed B sweep traces. In the TRIGGER section, you'll be able to select whether the B sweep simply Runs following the DELAY setting, or if it is TRIGGERABLE after the delay setting.Give it a shot, let us know how it works!