Tektronix 2465 as main scope - Page 1
Forum section: electronics / testgear

author: Tom314159
author_rank: Newbie
timestamp: August 12, 2016, 12:59:03 am
content: Hello all, first post here,I'm a little new to electronics and I had started looking for an oscilloscope some weeks ago. Then, to my delight, I found an old Tektronix 2465 300MHz scope in a dumpster; I was wondering how it compares to newer digital scopes. It's in near perfect condition and the calibration, while probably not up to spec, is good enough for me! I don't have that much to spend, and if the TEK is good, I'd rather spend my money on something else like a good function generator. Could I use it as my main scope? If so, what are the drawbacks of it? Thanks in advance.Tom

author: Hydrawerk
author_rank: Super Contributor
timestamp: August 12, 2016, 01:21:53 am
content: It is a very nice Tek scope. Once upon a time it must have been quite expensive.In general analog scopes have very few automatic measurements (or none) and they have no singleshot and waveform storage feature.

author: Electro Fan
author_rank: Super Contributor
timestamp: August 12, 2016, 05:22:11 am
content: Quote from: Hydrawerk on August 12, 2016, 01:21:53 am+1 for Hydrawerk's commentsThe biggest thing you will miss on an analog scope is likely to be the singleshot capture capability and then the pretty feature rich set of measurements that generally come with a digital scope but the 2465 has cursors and you can do some good basic measurements with the 2465. I'd say if it is free (from a dumpster) start with the 2465 and after you have a feel for what it does and doesn't do, you can always either sell it or keep it and add a digital scope. Just be careful when you get your first oscilloscope because there is a theory around here that 18 more will follow it into your lab.Seriously, the 2465 is a classic. Enjoy it.

author: tggzzz
author_rank: Super Contributor
timestamp: August 12, 2016, 08:28:55 am
content: If it works sufficiently well for your purposes, then it is an excellent scope. The worst that could happen is that you learn how to use and misuse scopes, and are then in a good position todefinewhat you reallyneedin another scope, andwhy.It has a sufficiently high bandwidth that you will be caught out by standard probing problems; that's part of the learning process. FFI, once you have got basic operation under your control, seehttps://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/As unnecessary icing on the cake, it can do basic measurements of voltages, frequencies, risetimes etc - but you should also learn how to do them manually.The only thing it can't do is capture single-shot transients. The only case where I have needed to do that is PSU turn-on transients, and for that a much slower cheaper digitising scope was sufficient.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 12, 2016, 08:56:11 am
content: I'd not recommend to buy an analog scope as a starter scope due to its inherent limitations. But hey, you got it for free, and on top of that it's one of the later ones which happen to have been one of the best general purpose analog scopes back in the day.I'd say keep it and learn how to use it. Just always keep in mind that this is an analog scope, and that, despite what some people say, not all techniques which are appropriate for analog scopes are necessarily useful when you later move to a digital scope.

author: David Hess
author_rank: Super Contributor
timestamp: August 13, 2016, 02:36:40 am
content: Later members of the 2465 family have some automatic measurement capability according to their specifications which I assume is similar to the 2247A series. I have experience with the 2247A but not any of the 2465 series so I am not sure how similar the measurement capability is.The 2465 is outside the performance range of what I would consider a beginner's oscilloscope but that price cannot be beat.

author: TiN
author_rank: Super Contributor
timestamp: August 13, 2016, 03:22:20 am
content: I was using 2246 for quiet few years, and sometimes today I miss it, even after use of mid/hi-range DSO's.2465 is a fine machine, and will allow you to do a lot of things you couldn't do without scope.Hell, I'd prefer 2465 to any of sub 1K$ digital scopes, only for reason that it'll teach you to do probing, measurements and learn the basics much better than those fancy touchscreeny modern scopes. Focus on the basics and why things do what they do, instead of just pressing buttons and looking at colorful lines, and you'll be just fine.Watch few of Dave's videos on scopes, may learn thing or two from there

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: August 13, 2016, 07:07:57 am
content: Fantastic scope! I use one. The 300MHz comes in very handy, trouncing all the budget DSOs at 100 or maybe 200MHz. You also get four channels, which is highly desirable. The cursors provide voltage, time, and frequency (see the manual) measurements.I feel analog scopes let you truly learn how to use a scope. All the knowledge will translate to a digital scope, and you will know how to use it much better than someone starting with only a DSO.As other have pointed out the single shot is not captured digitally. You can still do so with a camera set to bulb exposure (turn out the lights, open the shutter, capture). Single shot capture is a specialty thing I have rarely had a use for. It can help you see overshoot in a power supply, or capture digital pulses, but a logic analyzer is the right tool for that anyway.:-BROKEI would HIGHLY recommend you open it up and recap the low voltage power supply It does not require re-calibration, and these supplies are known to have caps that fail. Even if it seems to be working there are likely blow line caps in there.

author: Howardlong
author_rank: Super Contributor
timestamp: August 13, 2016, 07:28:43 am
content: I don't have experience of the original 2465 but I have plenty with the later 2465B which was my main go to scope for many years, even when I had a TDS2024 DSO. It has a few voltage and time measurement capabilities including rise time, and it's four channel, although two of those channels are limited as they only have a two setting low voltage attenuator, so mostly used for digital signals.The most complex part of the scope to get your head around is the delayed trigger with dual timebase, and the various modes it supports, but it's also one of its most powerful aspects.If it didn't take up so much table space I'd still have it on the bench. You can operate it at the bench while it's sat the floor, and that was the way I, and I'm sure many others, used CROs a lot of the time.Edit: Alan demonstrating the delayed trigger feature on a 2467, and I'm not sure I know of a DSO where you can achieve the simultaneous dual delayed trigger feature demonstrated here. (The 2465 and 2467 are very similar, the key difference is that the CRT in the 2467 is better for seeing infrequent signals due to its microchannel plate technologyhttp://w140.com/tekwiki/wiki/Micro-channel_plate_CRT).https://youtu.be/vvqVTD-VEow

author: David Hess
author_rank: Super Contributor
timestamp: August 14, 2016, 03:14:54 am
content: Quote from: Howardlong on August 13, 2016, 07:28:43 amThe 2247A series also include dual delta delayed sweep but it is somewhat obscure to access and of course their 7000 mainframes included it. With an analog oscilloscope, this feature allows slideback time measurements. The only DSO that I am aware of with it is the Tektronix 2440 series which were contemporaries of the 2465 series.

author: Skimask
author_rank: Super Contributor
timestamp: August 14, 2016, 03:42:35 am
content: Quote from: Tom314159 on August 12, 2016, 12:59:03 amDo yourself a favor and do some research on that model (or series of models) 'scope. It's a great 'scope. I've got one. Wouldn't trade it for nothing, but there can be some issues with cooling if a guy isn't careful. If that fan in the back craps out, you could heat up/overheat a couple critical chips/modules inside and kill it for sure, and pay thru the nose to find replacement parts. I keep mine on top of a laptop cooling pad that I run every time I turn on the 'scope. Just a bit of added insurance in case that rear fan takes a dump.And to be clear...which model...2465, 2465A, 2465B, 2465Mustard?

author: Tom314159
author_rank: Newbie
timestamp: August 14, 2016, 07:34:03 pm
content: Thanks for all the great feedback everyone! I'm definitely going to keep it and learn how to use it better. I found a pdf of the user manual and I'm currently reading that; it helps a lot because all of the knobs, buttons, and switches look confusing at first. I'll probably keep an eye out for any good deals, but for now I think it'll do.QuoteIt's model 2465. When I first saw it I hoped it was the 2465B, but I'm not complaining. If anyone cares, in the same dumpster I also scored an old analog function generator (1961!), two Keithley 177 Microvolt DMM's, two HV DC power supplies, and a variable AC/DC power supply. Everything works!Tom

author: TAMHAN
author_rank: Frequent Contributor
timestamp: August 14, 2016, 11:07:44 pm
content: The 177's, be careful if you have the GPIB options. They have a seperate voltage selector, which if set wrongly, kills a fuse on the option.Happened to me when I "slovakized" the 177 I got from the USA. Other than that, you will really like the unit tho. One last small bit of advice tho: if you buy new probes from China or somesuch, you need to cut off the "protective PVC" around the contacts. The 177 has "old style" binding posts...

author: nctnico
author_rank: Super Contributor
timestamp: August 14, 2016, 11:11:56 pm
content: Quote from: Tom314159 on August 14, 2016, 07:34:03 pmI'd sell most of it (the Keithley 177s and variable AC/DC PSU seem interesting enough to keep) and put the money towards a DSO.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: August 15, 2016, 12:11:43 am
content: Which 1961 function gen? I have this one:https://www.eevblog.com/forum/repair/function-gen-with-tubes-exact-240/msg771995/#msg771995

author: Tom314159
author_rank: Newbie
timestamp: August 15, 2016, 01:09:48 am
content: QuoteNo, not that one. It's an Eico 377, serial number 18319W. It does 0-200KHz (using four different ranges), and has an adjustable output of 0-10v RMS. It has a single switch to change between sine and square wave. I opened it up and "1961" was penciled on the inside of the case.Tom

author: TAMHAN
author_rank: Frequent Contributor
timestamp: August 15, 2016, 08:04:18 pm
content: Hello,I would not give up the stuff - a DSO can always be added later. But equipment which works fine really is worth it.Plus, re the Keithley 177: it is very difficult to sell them for a lot of money. I got mine for 25 bucks or so, plus shipment of course. IMHO, the meter is worth much more, definitely better than one of these POS carryaround multimeters everyone goes bonkers about. But I prefer desk instruments, ideally with a lab clerk reading out the measurings to me.Either way, find attached a pic of what I mean re the probes. The probes I used came right from the Chinaman (tm), whose shoppe can be found athttp://www.aliexpress.com/item/M007-1-1000V-20A-Needle-Point-Multi-Meter-test-probe-lead-for-digital-multimeter-for-tester/32367123747.html?spm=2114.13010608.0.57.rVL9Lv(no affilation BTW).