How to read the calibration (and other)signal(s) on Tek 3465? - Page 1
Forum section: electronics / testgear

author: Beamin
author_rank: Super Contributor
timestamp: October 16, 2017, 09:14:39 pm
content: Whats the best way to do this? I'm looking for step by step not something technical. I'm still trying to figure out the time selector. Like pull for channel two but why does the adjuster moves the outer time ring to the left but not right? What is the point of that?Most times I think I have found a signal I turn the device off and its still there but different from when its on.I set up a multivibrator with a few hundred kHz ( 10-100khz) but I still haven't really figured out how to find it. I think I have found a signal but I'm not sure. I set the multi vib. with an 10uf (slow ) electrolytic on one LED and a very fast (nf) (poly?) green cap on the other LED. I know the circuit doing something because you see the LEDs both dim one much dimer then the other. I have also picked up the same circuit with two small caps in the kHz range on my SDR.So my goals are:see waveFigure out sine vs squaremeasure frequencyUse both probes to compare the signal each LED is getting.Locate the "noise" signal that always seems to be present so that in future projects I can rule this outMake shapes on the XY modeThen:Convert the square to sine and compare (That's another LC circuit that is not hooked up yet)This is just the 3465 with "100Mhz" 12$ ebay probes

author: Beamin
author_rank: Super Contributor
timestamp: October 16, 2017, 09:49:11 pm
content: Ok I changed the multivib with two electrolytics where one led flashes at ~15hz and the other appears to stay on (the larger cap is attached (this cap makes them blink at ~1hz when I run both) so I'm not sure why the led appears to stay as a solid on and not flash).Does this scope have two guns for each channel? Is that what I'm seeing with the sharper top trace and the fainter bottom one? This has me stumped.

author: w2aew
author_rank: Super Contributor
timestamp: October 16, 2017, 09:52:55 pm
content: Quote from: Beamin on October 16, 2017, 09:14:39 pmThe "point of that" is that when you "pull" the timebase selector, it is not activating Channel 2, it is allowing you to make an adjustment for the 2nd timebase - this scope has a second "delayable" timebase. This was commonplace on performance analog scopes before the advent of digital scopes and Zoom...One of my first videos on my channel discusses the delayed timebase operation. Please excuse the quality - it was done with my cellphone about six years ago:

author: w2aew
author_rank: Super Contributor
timestamp: October 16, 2017, 09:56:18 pm
content: Quote from: Beamin on October 16, 2017, 09:49:11 pmNo, this scope has a single gun. You can view multiple channels using the ALT or CHOP vertical modes. Your screenshot shows that you have the delayed timebase active (I see the intensified portion of your trace) - this is not necessary... Rotate your timebase knob to the right until the outer ring turns, then push it in so that you're only adjust the main timebase.

author: Beamin
author_rank: Super Contributor
timestamp: October 16, 2017, 10:12:10 pm
content: DOH!I'm an idiot that first pictures where of a phantom signal the circuit wasn't on here is what it looks like:

author: Beamin
author_rank: Super Contributor
timestamp: October 16, 2017, 10:17:11 pm
content: Quote from: w2aew on October 16, 2017, 09:52:55 pmThanks I'm watching now. I have been watching your videos for sometime now, but didn't know that you were on this forum! Cool!

author: Beamin
author_rank: Super Contributor
timestamp: October 16, 2017, 10:52:26 pm
content: I'm getting ahead of myself. I still don't know if this scope works perfectly.Channels 2-4 when they are not plugged in are nice flat lines.Channel 1 "seems" noisy. But that might be how its supposed to work.I could find this out by using the test clip on the front correct?

author: tggzzz
author_rank: Super Contributor
timestamp: October 16, 2017, 11:35:15 pm
content: You could find all that out by RTFMing, where the M is the operators M.Good luck finding anything to do with a scope that is "not something technical".

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: October 17, 2017, 04:08:35 am
content: Strongly recommend going to w2aew's youtube channel and looking at the entire list of videos he has available. He has done a lot on the basic operation of scopes like the 2465 (2465, come on man, its in the screenshots you keep posting), as well as some on more advanced usage. You won't find better explanations of how those scopes work than his videos.Edit: Good videos to start with on his channel:#2: Tektronix delayed timebase operation#10: AC / DC Coupling on an Oscilloscope#11: Tektronix Oscilloscope Triggering controls and their usage#16: How to use the Oscilloscope to accurate capture 2 signals of different frequencies#17: Using Analog scope to view two signals of wildly different frequencies#18: Use Oscilloscope with delayed time base to measure a RF Power detector#19: How to get a stable scope display with two signals very close in frequency#25: Analog Oscilloscope bandwidth considerations#31: Analog oscilloscope ALT, CHOP, ADD, INVERT vertical controls#33: Oscilloscope AUTO Triggering explained#35: Using the ADD/INVERT mode on an analog scope to view differential voltagesJust a few out of the first 35, there are many more on his channel

author: Beamin
author_rank: Super Contributor
timestamp: October 17, 2017, 06:48:38 am
content: Quote from: tggzzz on October 16, 2017, 11:35:15 pmQuote from: CustomEngineerer on October 17, 2017, 04:08:35 amtgzzz: What is "RTFM'ing" and the operator M? Then look at the second quote or the posts with all the great video responses. Which response do you think is more helpful?My gripe with technical forums: Some one asks a beginner question and people look at their low post count and respond with a two line overly technical term that they know the OP will have no clue about, followed by humorless sarcasm. Why do people do this? Are they trying to make themselves look smart to the other members that will understand your technical terms? This kind of arrogance really turns off beginners to not just the forum but the entire hobby. Think if every time a beginner asked a question the only responses they got were like yours. Did you find those kind of responses helpful when you were a beginner? No? I didn't think so. You know what I meant when I said something not overly technical. So the first thing you post is something overly technical that says "Hey everybody look how much smarter I am than the person who just bought an oscilloscope a week ago! Are they not dumb for asking such a stupid question and not automatically knowing how to work a complicated piece of equipment?" (Yes I know in your head right now you are thinking "An oscilloscope is not complicated: I figured out how to use mine in five minutes") A better way to make yourself look intelligent is to be able to communicate your knowledge into something everyone can understand. The most intelligent people are the ones who can, and do, contribute the most. Or better yet stop trying to put other people down to feel better about yourself. You will become more likable too!And also I know its the 2465 but you can't edit titles of threads so my typos tend to stick. Or maybe it's a 3465 in a 2465 case?Back to RTFM'ing where M is the operators M.

author: tggzzz
author_rank: Super Contributor
timestamp: October 17, 2017, 08:43:31 am
content: Quote from: Beamin on October 17, 2017, 06:48:38 amhttps://www.google.co.uk/search?q=define+rtfmingso you could infer operator M is the operators manual.QuoteTo start with 291 is not a low post count, and post count is an irrelevant metric anyway.But to answer your question...My gripe with technical forums is that people ask questions that they could very easily answer themselves by a little homework with the obvious high-quality information sources. Instead they expect other people to spend time doing their homework for them; the response will inevitably very truncated and of poorer quality than the obvious source.In this case if you can't be bothered to read the manual,especiallybecause you think it is "too technical", then you shouldn't be using a scope. But then that's true forallinstruments and tools.I'm not the only person that gets frustrated by that form of laziness, e.g.http://www.catb.org/esr/faqs/smart-questions.htmlhttps://entertaininghacks.wordpress.com/library-2/good-questions-pique-our-interest-and-dont-waste-our-time-2/Famously, back in the early 80s someone pointed that out simply by posting a message "What time is it?". The group's readers took the hint.

author: Beamin
author_rank: Super Contributor
timestamp: October 17, 2017, 07:04:11 pm
content: Quote from: tggzzz on October 17, 2017, 08:43:31 amYou have a point and you would have no way of knowing if I have already tried looking something up vs just asking. So I see how it could look like I was just being lazy. Sometimes I will ask semi rhetorical questions on forums with the hopes that other beginners on the forum and google search can find it and learn something rather then just make the question help just me.

author: tggzzz
author_rank: Super Contributor
timestamp: October 17, 2017, 07:45:29 pm
content: Quote from: Beamin on October 17, 2017, 07:04:11 pmCorrect; it does. But your subsequent statement (see below) puts you in a different and even less flattering light.Now if you had bothered to read the second reference, you would have seen...Saywhat you know and don’t know. It encourages us to answer, and itdemonstrates respectbyavoiding wasting everybody’s time:we’ll realise you have already attempted to help yourself (and how), and only then are asking us to help youyou won’t receive a “STFW” or “RTFM” response; too often those responses are perfectly reasonable, even if they are tersewe won’t waste time suggesting things that you have already tried, and which have failedwe won’t waste time making points you already knowwe won’t waste time giving answers that you won’t understandwe won’t feel you’re asking us to do your job or homework for you. N.B. people are often willing to help you with your homeworkwe’ll realise this isn’t a spur-of-the-moment question, and that the answer is important to youThe first ref makes similar points as well.QuoteSo, you ask people to spendtheirprecious time providing answers that youalready know, because itmightbe good for somebody or other.Your presuming other peoples' time is of little value is extremely thoughtless and/or downright rude.Read those references, and ponder what they are saying and why they are saying it.

author: rstofer
author_rank: Super Contributor
timestamp: October 17, 2017, 08:51:51 pm
content: Besides all the other reference material above, here is the User Manualhttp://www.download-service-manuals.com/download.php?file=Tektronix-2522.pdfPage 5.1 has an Initial Setup process to get a trace on the screen.Basically, the calibrator output will put a number of cycles on the screen and the frequency changes along with the Time/div knob - in other words, the frequency varies between 5 Hz and 5 MHz as it says on the panel.Pick a time scale - say 1 us per division. There should be a square wave trace on the screen if you followed the Initial Setup process.And by all means, reset that time/div setting such that both channels track.In the manual for the 2465B, there was a comment about an Auto button - if you have one, connect the signals and push it.Mode should probably have only Ch1 depressed at this point.

author: Beamin
author_rank: Super Contributor
timestamp: October 18, 2017, 12:46:38 pm
content: Quote from: tggzzz on October 17, 2017, 07:45:29 pmOk. I didn't realize people who spend their days on the internet had so little precious time. They do always have the option not to respond if indeed their time is that valuable. I think some people just like to lecture other people. For instance look what kind of shit storm will ensue if you start asking questions about using and transmitting on a ham radio and don't have a license. People will freak out and start lecturing you like they do their kids. All of a sudden you have committed a serious crime and they are the head of the FCC. It's like they think their knowledge and time is so valuable and others should be grateful to be lucky enough to have a glimmer of their divine enlightenment. It's internet; it's not like they are the dahli lamah and you are seeking true wisdom... it's just some forum on the internet. Its so arrogant to think about how vastly more valuable your time is then someone else's. We all get 24 hours in a day and if they think their time is so valuable they need not be killing time playing with the internet.

author: tggzzz
author_rank: Super Contributor
timestamp: October 18, 2017, 01:14:33 pm
content: Quote from: Beamin on October 18, 2017, 12:46:38 pmYou must be young. As you get older you realise your life is finite, and you have to choose how to spend what's left.Myself, I enjoy helping other people learn more and do more than they believed they could. I try to pick people where that will happen.I deeply resent people that piss around and play silly thoughtless games, because it stops me helping someone thatcouldbenefit from my time.Others feel the same.To put it another way, how would you feel if you had gone to the trouble of trying to help someone, only for them to turn round and say "oh, ha ha, my game, I didn't need your help anyway".

author: rstofer
author_rank: Super Contributor
timestamp: October 18, 2017, 04:21:06 pm
content: Quote from: tggzzz on October 18, 2017, 01:14:33 pmI agree, 'rhetorical questions' are a PITA; I'm much too old for playing games. The simple solution is to just ignore the posts and move on.It's sometimes difficult to separate the folks with a legitimate question from those who are just trolling.

author: tggzzz
author_rank: Super Contributor
timestamp: October 18, 2017, 06:04:20 pm
content: Quote from: rstofer on October 18, 2017, 04:21:06 pmJust so.However this one shows signs of listening and understanding (kudos to them!), so there's the possibility of redemption followed by a useful life

author: Beamin
author_rank: Super Contributor
timestamp: October 18, 2017, 09:10:08 pm
content: Quote from: tggzzz on October 18, 2017, 06:04:20 pmWhich them are you referring to? I don't mean to make rhetorical questions to be time wasters I often learn something I didn't know from asking basic questions by learning new aspects or other approaches to the question.I really did get a lot out of that "how to ask questions post" it was also very well written. I sometime have a hard time sticking to the point.