Seeking affordable MSO Oscilloscope - Page 1
Forum section: electronics / testgear

author: ChanceMcCrance
author_rank: Newbie
timestamp: January 07, 2017, 12:34:29 am
content: I am a college student on rather limited budget and I am seeking a new or used mixed signal oscilloscope (not pc based or handheld) with minimum bandwith 20 MHz and up with at least 2 channels. When I say limited budget, I mean under $300. Basically I am asking for a unicorn. However, if there is such a scope that exists, I figured this would be a good place to look. If anyone is selling such a scope, or has any information on where I could get one, please post. I know what I am asking for is pretty tough to come by, but any information would be appreciated.Also, I just found a deal on a decent looking MSO online. The bandwith, sampling rate, and # of channels seem sufficient, but I am not sure if this is a good product. I am looking at a HP Agilent 54622D 2+16 Channel 100MHz Mixed Signal Oscilloscope. Does anyone know if this is a good scope?

author: cheeseit
author_rank: Regular Contributor
timestamp: January 07, 2017, 12:48:11 am
content: For what it's worth I would think so. A bit old but good though I wouldn't know if there is anything more modern and better in your price range. I had a 54621A that I quite liked and found the UI nice to use. I'm sure someone more knowledgeable will reply soon.

author: Amazing
author_rank: Regular Contributor
timestamp: January 07, 2017, 07:39:43 am
content: Did you see the Dave Jones review on this scope?He seems to like it. But I'd have a hard time recommending something that old if you don't have the budget to fix it if it breaks.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 07, 2017, 08:23:37 am
content: All the old Hp/Agilent MSOs, even the first 54645D are perfectly decent units, and are pretty cheap nowadays.Try to find one that still has the MSO cable as these are hard to find on their own, as they get swiped for use on later DSO models that have been hacked to enable the MSO

author: nctnico
author_rank: Super Contributor
timestamp: January 07, 2017, 11:42:50 am
content: Quote from: ChanceMcCrance on January 07, 2017, 12:34:29 amIMHO it is a good scope. I had one on my bench at a former employer 15 years ago and it served me well for FPGA development.

author: PaulAm
author_rank: Frequent Contributor
timestamp: January 07, 2017, 02:44:06 pm
content: I have a 54645d, the 622d is the follow on. They're nice easy to use scopes and the 622d can have the firmware updated.As noted, the biggest problem is the logic pod; you can easily pay more for that than the scope. Somebody was making an adapter that used a common HP cable for like $50 on ebay for a while. The connector is a standard 40 pin connector, but it's recessed a bit so a regular idc header doesn't quite work.The pod was common across a number of instruments so you might get lucky. I found mine attached to a 54620a LA (got the whole deal for $50).There is I2C and SPI triggering capability, among others, but it doesn't do serial decode. If you need that you can probably do with a bus pirate.

author: ChanceMcCrance
author_rank: Newbie
timestamp: January 08, 2017, 12:46:56 am
content: Thanks. This was really helpful. I found a deal for this scope online which includes all of the original test probes, power cable, user manual, etc. I've decided to go for it. I am really happy that I joined the blog. Looks like I've found a great community!

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 22, 2017, 01:52:58 am
content: What is the difference between the HP54645D and the HP54622D, apart from the fact that the firmware of the latter one can be updated?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 22, 2017, 09:52:55 am
content: 54622 has floppy drive and parallel/serial ports/FFT as standard - latter were a plug-in option on the 54645D54622 has intensity grading- I don't think the 54645 did

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 22, 2017, 12:00:20 pm
content: If I can choose between both units, I still would go for the HP54645D as it looks a more solid design.Was it for cost reduction reasons that HP changed to the cheap-looking design, with flimsy round buttons?What was wrong with the older design? It looked much more professional, and the keys were much better quality.

author: nctnico
author_rank: Super Contributor
timestamp: January 22, 2017, 01:03:39 pm
content: Quote from: pascal_sweden on January 22, 2017, 12:00:20 pmWhere I worked we always had a bit of a fight over who got the 54622D instead of the (lesser 54645D) so you better get the 54622D. As explained before judging test equipment by the way it looks is not a good habit. For a good comparison you have to at least consult the datasheets and sometimes the limitations are only mentioned in the user manual.

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 22, 2017, 03:46:09 pm
content: The buttons on the HP54622D seam to wear out. The top plastic coating seems to come off.The buttons on the older HP54645D model seem not to be affected as much.Is it still possible to source new buttons for these 54600 series scopes?Or should one go for 3D printing? Are there any people out here with experience in either sourcing genuine buttons or fabricating new replica buttons through 3D printing techniques?

author: Micke
author_rank: Regular Contributor
timestamp: January 23, 2017, 08:40:07 am
content: I would definitely go for the 54622D rather than the older 54645D.Before, I had a HP 54645D, but got a chance to buy Agilent 54622D at good price, and liked it much more, so I sold the 54645D.The more modern 54622D has more flexible triggers, SPI, CAN and I2C etc. The 32 levels of intensity graded display is really nice, and the waveform refresh rate is much higher on the 54622D.It almost feels like an analog scope!I did like previous poster mentions, bought an old HP Logic Analyzer boat anchor (think it was HP 1650B) cheaply to get the special woven ribbon cables and the pods.

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 23, 2017, 10:20:06 am
content: Maybe it is a personal thing, but I like the dark background on the HP54645D better than the light green background on the HP54622D. The light green background makes it harder to read the grid.

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 23, 2017, 02:31:32 pm
content: Interesting to learn that the 54600 scope series from the nineties had already models with 8M memory, which is more than the 4M memory which the current series from Keysight have in the same bandwidth range (100-200 MHz).Are we talking about evolution or recession?From HP to Agilent. From Agilent to Keysight. From 8M in the nineties to 4M in 2017! Way to go Keysight!

author: ebastler
author_rank: Super Contributor
timestamp: January 23, 2017, 02:47:13 pm
content: Quote from: pascal_sweden on January 23, 2017, 10:20:06 amHmm, is there really a difference?Have you used both scopes, or are you assessing this based on photographs?

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 23, 2017, 03:05:38 pm
content: See for yourself!HP54645D: Dark background with very good contrast - quality buttons built to lastMetal case and front panel - Grouping of buttons is perfect!The 54645D MSO is designed and built to the rugged requirements of MIL-T-28800.HP54622D: Light green background with less good contrast - cheap and flimsy buttonsPlastic case and front panel - Grouping of buttons is not so good!It is questionable if the 54622D MSO still meets the rugged requirements of MIL-T-28800.

author: nctnico
author_rank: Super Contributor
timestamp: January 23, 2017, 03:25:41 pm
content: The differences between the videos are probably due to lighting and camera equipment. Besides that you can adjust the brightness to your liking. An TFT conversion on a HP54622D would be a neat project thoughI haven't done one in a while and it is fun to do:

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 23, 2017, 04:21:33 pm
content: Quote from: pascal_sweden on January 23, 2017, 03:05:38 pmIt's a while since I had one but I'm pretty sure it was an all-plastic case.

author: ebastler
author_rank: Super Contributor
timestamp: January 23, 2017, 06:46:27 pm
content: Quote from: pascal_sweden on January 23, 2017, 03:05:38 pmBut you can easily find images on the web where it looks the other way round.https://metalab.at/wiki/images/3/34/HP54645D.jpghttp://www.alliancetesteq.com/sites/default/files/test-equipment/54622d.jpgI would think that this depends a lot on the external lighting and the camera settings when the video or photograph was taken. To really "see for yourself", you would have to look at the live instruments.I can understand your preference for "serious" looks of an oscilloscope over the newfangled, rounded rubber buttons. But for a piece of T&M equipment, if in doubt I would be guided by its technical merits, and the '622D seems well ahead in that respect. Heck, I'm even happy to accept the decidedly toy-like looks of my DS1054Z, because I like its functionality (for the price)...