Opinion on Tektronix 2246 vs 2445 - Page 1
Forum section: electronics / testgear

author: wmundstock
author_rank: Contributor
timestamp: April 20, 2023, 12:49:03 pm
content: Hi.I own a Tek 2246 100Mhz 4 channel scope and found a good Tek 2445 150Mhz 4 Channel in good condition with reasonable price in my region.Honestly I always wanted a 2465B but those are rare and very expensive here and it has that "battery" concern.Can you share your opinion on the 2246 and 2445?Would it make any sense to "upgrade" to the 2245?Which scope do you prefer and why?Any pros and cons that I should consider?Thank you!

author: Sarvesaa
author_rank: Contributor
timestamp: April 20, 2023, 12:52:00 pm
content: If thats cheap and you can afford it then go for it.

author: bdunham7
author_rank: Super Contributor
timestamp: April 20, 2023, 01:37:09 pm
content: I have one and it is a very nice scope, but I'm not sure how much of an upgrade it is from a 2246 as they seem to be at a very similar feature level. The 2445 has a bit more bandwidth but it also has a less-focused or wider-trace screen because it uses the same mesh-expansion CRT as the faster 2465/A/B. I believe the 2445 also has a few features that the 2246 doesn't, like dual B-sweeps, but nothing major. All in all, it is probably an incremental upgrade.

author: jwet
author_rank: Frequent Contributor
timestamp: April 20, 2023, 01:57:59 pm
content: The 22xx series was designed to be a lower cost alternatives to the 24xx series which were pro scopes. The models overlapped a bit but 2200 were much cheaper -50% and as bhunham7 said, had better screens and focus. I had a 2225, the low, low end of the series it was sort of the Rigol of its day- early 90's at about a grand. The comps were Hitachi and old used machines from the 450/460 series which were still 2k. I later upgraded to a kind of a worn out 2465 because "I always wanted one". It was nice but I never pushed that 300 MHz BW. I still have it somewhere. They don't fetch much in the US and non working they're free for pickup.I think I'd stay with your 2246. Its about 5-10 years newer most likely and its the devil that you know. Tek is pretty conservative on BW, so the difference there is dubious. We're talking about 30-40 year old stuff here.Theee were the last of the all analog scopes- from here, they did 2430's, etc that were 100MS/s digitals with CRT displays and the monochrome LCD lunchbox 200 series that began the move to modern scopes. About 15 years ago, I got a 3054 series for a steal that will likely be my last expensive scope. I have a vacation house where I wanted a minimal lab and picked up a Rigol 1054, that is a lot of scope for 400!This sounds like Test Equipment Anonymous- short answer- stand pat unless you're a collector.

author: wmundstock
author_rank: Contributor
timestamp: April 20, 2023, 02:17:26 pm
content: Quote from: jwet on April 20, 2023, 01:57:59 pmThanks for the review and for the advice.I do like the dual b-sweep feature on the 2445 mentioned by bdunham7. Problem is I also like the ground and trigger tracking features on the 2246 - not present on the 2445. Maybe I'll just wait until I find a 2465B which I can afford to show up. Here in Brazil they are rare and expensive - there are only a couple that I know of and they are listed for 1100 USD and up.

author: jwet
author_rank: Frequent Contributor
timestamp: April 20, 2023, 02:29:40 pm
content: I'd ship you mine but it might be $1100 too after shipping and customs- 2465's are HEAVY.

author: Electro Fan
author_rank: Super Contributor
timestamp: April 20, 2023, 04:49:05 pm
content: Quote from: wmundstock on April 20, 2023, 12:49:03 pmThis doesn't exactly address your questions but fwiw, I have a 2467B and a 2247A. The 2467B is cool and sort of legendary but unless the higher bandwidth of the 2467B is needed I prefer the controls/UI on the 2247A. I'd skip the 2245 and either go for a 2465B, or if you can find one, go for a 2247A (but keep your 2246 until you confirm the 2247A is as expected). The 45, 46, and 47 are similar but the 47A is the ticket if you can find one in good condition.Really, unless you need more bandwidth, you can stand pat with the 2246 (or sell it/trade up for the 2247A). For about the price of a second vintage Tek analog scope you can buy a pretty nice digital scope (if you don't already have one). I love the Tek analog scopes but if you told me I could either have a 2467B plus the the 2247A or a Siglent SDS2104X Plus, I'd probably have to go with the Siglent SDS2104X. For the price of a 2445 it would make more sense to go with a Siglent or Rigol oscilloscope, especially since you already have a Tek analog scope. The only reason to do otherwise is if you are a Tek vintage collector, in which case there is a thread to help with that...https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/Keep us posted on what you decide and how it goes.

author: David Hess
author_rank: Super Contributor
timestamp: April 20, 2023, 06:19:12 pm
content: Quote from: bdunham7 on April 20, 2023, 01:37:09 pmI would double check that. I think both the 2246 and 2247A/2252 support dual b-sweeps through an obscure control setting. But maybe it is only the 2247A/2252? My 2246 is in storage at the moment so I cannot check.Quote from: jwet on April 20, 2023, 01:57:59 pmThe 4 channel 22xx series like the 2246 were intended as service oscilloscopes rather than laboratory oscilloscopes, so they have a different feature set despite being contemporaries of the later 24xx series.Quote from: Electro Fan on April 20, 2023, 04:49:05 pmOr a 2252 which has every feature of the 2247A plus digital storage which can be ignored. Note that the 2252 is *not* a DSO despite having digital storage; it is more like screenshot capability for repetitive signals to make a hardcopy for documentation purposes.

author: wmundstock
author_rank: Contributor
timestamp: April 20, 2023, 08:23:51 pm
content: Quote from: Electro Fan on April 20, 2023, 04:49:05 pmI do not "need" the extra 50 Mhz. My application is more for learning as a hobbyist. I have a Keysight EDUX1052 2 channel 50Mhz which is pretty decent for digital, serial etc signals. But I do enjoy using the older analog scopes. I tend to use the Tek much more often than I use the Keysight. Not sure there is a reason for it, I just like it better.Maybe I just do have a small (emphasis on small) problem with testing equipment. I do get some buzz from taking an old/new equipment and testing it. Perhaps I should join the TEA group.Quote from: David Hess on April 20, 2023, 06:19:12 pmGood Lord! I was not aware of that, you are 100% correct! It is, indeed, kind of hidden in crazy menu combinations. OMG that made my day! Thank you sir!In fact you can not only have two sweeps but you can have one sweep on each channel!!!In case someone else want to know how: In the 2246, you just do the B-Sweep setup as you normally would, then click the Time menu, select |-Time -| option then when you turn the delay you move the fist sweep, when you turn the time position button you increase or decrease the delay between the sweeps, thus creating a second line. Below a picture of what it looks like.Instructions are in the section 6-17.

author: jwet
author_rank: Frequent Contributor
timestamp: April 21, 2023, 02:15:42 am
content: My 2225 had some kind of lame alternate sweep mode that worked ok for as much as I needed it. I remember talking to a Tek rep at a show and he said that something like 5% of customers understood delayed sweep and its nuances and 1% used it. The 22xx didn't have all the super jazzy dual sweep with delay multiplier and mag/mag, etc. That horizontal on the 24xx series could do anything- I don't know if I ever completely exercised it.

author: wn1fju
author_rank: Frequent Contributor
timestamp: April 21, 2023, 12:42:34 pm
content: Another vote for the 2246. I have several 22xx scopes at home and have used several 24xx scopes at work. The 2246 is my favorite in terms of user interface, features, screen brightness/clarity and serviceability.

author: tggzzz
author_rank: Super Contributor
timestamp: April 21, 2023, 04:03:01 pm
content: Quote from: wmundstock on April 20, 2023, 12:49:03 pmWhat would you be able to do with the 2245 that youcannotdo with your (working) 2246? If nothing, then there is nobenefitto having the 2445.What is the best use of your money? Another scope, or a logic analyser, or spectrum analyser, an HV differential probe, or...What do you want to have achieved in, say, 1 year? Learned the buttons on a new scope, or learned how to use a completely different tool to solve different problems, or...

author: wmundstock
author_rank: Contributor
timestamp: April 21, 2023, 09:50:36 pm
content: Quote from: tggzzz on April 21, 2023, 04:03:01 pmI thought the dual B sweep could be one. And when I created the post, that is the kind of information I was hoping for. Is it worth? Is it really an upgrade or just a side shift?The feedback overall seem to be that other than bandwidth, there isn't much to call upgrade on the 2445.Quote from: tggzzz on April 21, 2023, 04:03:01 pmNoted. I just came across that oscilloscope and thought it could be an opportunity for upgrade. But you may be right... perhaps investing on a completely different tool could expand my knowledge and be a better use of the money. Thanks for the advice.

author: tggzzz
author_rank: Super Contributor
timestamp: April 21, 2023, 10:27:25 pm
content: Not advice, merely some questions for you to think about. Often answering questions is easy, but it is more difficult to know which questions are worth answering.In my opinion being able to use a B sweep to "zoom in" is pretty fundamental. When I found some later Tek scopes (e.g. TDS340) couldn't do that, I was more than a little irritated! My recollectiom, possibly faulty, is that it is possible on 22x5 scopes, but is nowhere near as convenient as on the 4x5 and 24x5 scopes.It is always pleasant to converse with someone that both listens and thinks.Have fun

author: bdunham7
author_rank: Super Contributor
timestamp: April 22, 2023, 03:25:15 am
content: Quote from: tggzzz on April 21, 2023, 10:27:25 pm22x5 scopes is not a good way to categorize. The 2215 and 2235 have a full dual timebase implementation, you set the A and B sweep rates, dial in the delay and there you are. They both even have B-triggers. The only advantage the 24x5 scopes had AFAIK is the dual-B-sweep. The 2225, OTOH, just has a lame magnifier setup and not any sort of dual timebase.You can pick on the poor TDS340, but full-on DSOs really manage things differently with zoom. With only 1000 samples, there's not much you can do.

author: tggzzz
author_rank: Super Contributor
timestamp: April 22, 2023, 08:47:07 am
content: Quote from: bdunham7 on April 22, 2023, 03:25:15 amThe 1000 samples was a common problem, especially where a CCD was used as the sampling mechanism for later slow digitisation. It made digitising scopes pretty dire for general purpose use, but was tolerable for the USP of capturing a single-shot event. The stunning advances in ADC performance have greatly improved the usability of modern digitising scopes.I've only played with one 22x5 (a 2245), so I bow to your judgement about the others. Nonetheless, I found the delayed B-sweep functional, but the ergonomics were poor compared with the 245 scopes.

author: m k
author_rank: Super Contributor
timestamp: April 22, 2023, 12:26:41 pm
content: I remember that my 2215A was triggering pretty well, better than 465, but it was new.