Phillips/Fluke PM3394 Combiscope Help - Page 1
Forum section: electronics / testgear

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 22, 2018, 02:24:14 am
content: Hey, a few months ago I bought a used Phillips pm3394 200mhz combiscope (for 130 USD, good deal) and have some questions on it.1. How to use the z-mod input on the back?2. I'm not sure if it is a pm3394A or pm3394B. How can I tell?3. When the oscilloscope turns on, the traces don't appear in the center of the screen. Once the instrument warms up (The software won't say "warming up" anymore when the autocal is pressed) the traces gradually move towards the center of the screen and align. What is wrong here? Is this normal?Thanks to anyone who gives an answer!

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 22, 2018, 01:45:45 pm
content: Bump

author: ArthurDent
author_rank: Super Contributor
timestamp: January 22, 2018, 02:47:20 pm
content: This may or may not help but the 287 page service manual is available as a free download. It doesn't look like it tells you much about the operation.http://elektrotanya.com/fluke_pm3370a_3380a_3382a_3384a_3390a_3392a_3394a_sm.pdf/download.html

author: wn1fju
author_rank: Frequent Contributor
timestamp: January 22, 2018, 07:36:54 pm
content: 1) The Z-mod input is used to (dynamically) vary the intensity of the trace. I have never found an occasion to use it, but if you google "oscilloscopez-modulation," I'm sure others have.2) Doesn't the label above the CRT tell you whether it is a PM3394A or PM3394B. My "B" model is clearly marked, and besides, the "B" model also says"25 GS/s repetitive sampling," unlike the "A" model.3) My PM3390B (2-channel variant) also exhibits a baseline shift of about 2 minor ticks upon startup and returns to the center in about 10 minutes. Mustjust be the nature of the beast.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 22, 2018, 08:51:35 pm
content: Thank you! I got the z mod working by applying about a volt of dc to the back bnc connector. My oscilloscope says phillips on it, not fluke, so I'm not sure what model it is. It doesn't say A or B on it. I'm glad that the shift of 2 ticks is fine, and not a problem. Once again, thanks a ton.

author: David Hess
author_rank: Super Contributor
timestamp: January 23, 2018, 12:12:26 am
content: Quote from: wn1fju on January 22, 2018, 07:36:54 pmThis varies between oscilloscope models and even different examples of the same oscilloscope model. 2 minor divisions of display shift is acceptable.I usually notice the change in brightness more as they warm up.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 23, 2018, 12:47:37 pm
content: Press "UTILITY" > MaintenanceThis will give you all the details about your scopeIncluding installed optionsA cold PM3394 scope will always show the beam a little high.If you give the scope about 30 min warmup time, the beam should be right on the "-" sign for that channel.If not, press and hold the CAL button for a couple seconds, until the self-cal will start.If the the beam is still not perfectly on the "-" sign after a couple of self calibration cycles,You might need to have a manual calibration done.BTW, the password for all of these PM33xx scopes is 32415

author: HighVoltage
author_rank: Super Contributor
timestamp: January 23, 2018, 12:57:35 pm
content: Here is a screen shot of one of my PM3394BThis one has all options and the latest FirmWare installed.

author: grumpydoc
author_rank: Super Contributor
timestamp: January 23, 2018, 01:37:34 pm
content: Service manual for the original 3394 - there wree several changes in the "A" and "B" versionshttps://www.wild-pc.co.uk/docs/pm3382rev.pdfUser manual - for the "B" version but close enough.https://www.wild-pc.co.uk/docs/pm33xx__umeng0200.pdfReference manualhttps://www.wild-pc.co.uk/docs/pm33xx__rmeng0400.pdfNice 'scopes

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 26, 2018, 08:45:14 pm
content: Mine says firmware 1993 so I think I have the original.EDIT: Original, not A.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 27, 2018, 05:34:10 pm
content: Anyone know how to get saved waveforms off the scope via rs232? CPL protocol? Thanks.

author: kripton2035
author_rank: Super Contributor
timestamp: January 27, 2018, 06:35:12 pm
content: chapter 6 of the user manual...https://www.allaboutcircuits.com/test-measurement/oscilloscopes/pm-3370b-80b-90b-84b-94b-pm-3380b/manual/

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 27, 2018, 06:39:18 pm
content: Yes, I have read the manual, but am quite unfamiliar with the protocol and the 25-year-old tech used. A more descriptive example would be nice. Maybe HighVoltage can help (as of 2015 he owns at least 6 of them). I'm guessing the example program used will take whatever digital trace is stored on the screen and export it as a file. How would I execute it? What kind of program do I need to send the program via rs232?

author: grumpydoc
author_rank: Super Contributor
timestamp: January 27, 2018, 07:04:19 pm
content: Quote from: AutogolazzoJr on January 27, 2018, 06:39:18 pmYou send a "QW" (Query Waveform) command.You get back some housekeeping info, then the data, two bytes per sample.Page 6-35 and 6-36 in the manual.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 27, 2018, 07:35:09 pm
content: Use the original software that came with the scope, it still works pretty well under Windows Xp

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 27, 2018, 07:36:01 pm
content: I bought it used, it didn't come with anything. Can you send me the software? thanks

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 27, 2018, 07:37:20 pm
content: Also, may I confirm that this is the right type of cable?https://www.ebay.com/itm/292367569129?var=591250980835Thanks

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 28, 2018, 01:26:37 am
content: Keep in mind I have the phillips pm3394a version

author: Bratster
author_rank: Frequent Contributor
timestamp: January 28, 2018, 02:19:02 am
content: Quote from: AutogolazzoJr on January 27, 2018, 07:37:20 pmEdit: I stand corrected, it is a standard null modem cable.Let me go look at mine, I think I have a wiring diagram for it.Edit: pinout attached.Sent from my Nexus 6 using Tapatalk

author: Bratster
author_rank: Frequent Contributor
timestamp: January 28, 2018, 02:24:17 am
content: Also for taking screenshots of the scope, a plotter emulator software will work. You just set up the plotter settings in the scope to match what the plotter emulator program wants and then the scope just thinks it's sending out to a plotter.The software that I use is part of this:http://www.ke5fx.com/gpib/readme.htmIt is a package of software that can do a bunch of different things. But it has the plotter emulation software in it. You just need to configure it for rs-232 as opposed to gpib.I would also be interested in the official software for the combiscope if someone has it.Sent from my Nexus 6 using Tapatalk

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 28, 2018, 02:57:26 am
content: Interesting. The pm3394B manual mentions a null modem cable? Anywhere I can get a a cable like that, or one to modify into?

author: egonotto
author_rank: Super Contributor
timestamp: January 28, 2018, 04:27:34 am
content: Hello,I think the Null Modem Cable you link is ok.I have a frugal C++ program for Visual Studio 2005 to read trace to computer.Best regardsegonotto

author: ps
author_rank: Regular Contributor
timestamp: January 28, 2018, 11:18:35 am
content: Quote from: wn1fju on January 22, 2018, 07:36:54 pmThat should be the case, unless the scope has been upgraded by some user. PM3394, PM3394A and PM3394B have clearly different labels.

author: grumpydoc
author_rank: Super Contributor
timestamp: January 28, 2018, 01:46:50 pm
content: Quote from: wn1fju on January 22, 2018, 07:36:54 pmThe model number is printed on the front panel and is shown on the status screen as demonstrated in the photo HighVoltage posted above.There is no ambiguity - if there is just a plain model number without "A" or "B" then it is one of the original series, if it is a newer 'scope the model number will end in "A" or "B"Quote from: ps on January 28, 2018, 11:18:35 amThe two model numbers could be different if someone has replaced the CPU card with one from a later 'scope - this won't "upgrade" the 'scope as such - except that there were supposedly bugs in the CPL interpreter which made some things not work over RS-232 which weren't fixed until the "B" version. I don't have the exact details of what the bugs were.I'm not actually sure what "upgrades" are possible or meaningful for this series of instruments. They are actually fairly tolerant of swapping boards between the series although there were minor changes in the schematics over time. In particular the A/B version of the CPU card is quite a bit different to the original and the EEPROM's are soldered in so it isn't possible for the user to change the firmware. There were rumours and hints in the manual that a PC program existed for firmware updates but I have never seen even the slightest clue as to a copy on the 'net.There were also minor front panel changes between the original and A/B series so I would only really suggest putting a "B" CPU card into an "A" chassis to get the firmware updates.They are also pretty tolerant of swapping the A8 board between 'scopes. If you put a 100MHz A8 board in a 200MHz 'scope you get a warning (and vice-versa) but it works. In theory the A8 board only differs in a few components between the two but the only attempt that I made to "upgrade" a 100MHz A8 board to a 200MHz one ended in disaster. I think I know what I did wrong but don't have an inexhaustible supply of boards to wreck getting it right. In any case if you change the ID resistors it will go in fine without any error and can be calibrated to the 200MHz spec so there isn't all that much point.It isn't feasible to upgrade a 100MHz chassis to 200MHz bandwidth - the front end has a relatively small number of component differences (but a lot more than the A8 board) but the CRT, delay line and final X/Y amplifiers differ physically.Swapping the CPU card to gain the maths package or GPIB would be reasonable but the supply of faulty 'scopes has dried up (at least on eBay) so in practice unlikely. You can't just populate the empty GPIB hardware on the CPU card as the firmware on a non-GPIB version will not know how to drive it (as well as the hardware interface here is an entire command interpreter as well).The only other upgrade which is feasible in practice would be to increase the amount of DSP/acquisition RAM on the A8 card but, again, I tried this and the card was unstable afterwards. Not sure why.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 28, 2018, 02:05:21 pm
content: Thanks. I have the original version (PM3394), not A or B. Firmware 1993. I plan on using that 3-wire null modem cable and running some of the examples in the B version manual using PC-BASIC, a GWBASIC emulator. I will probably need a little more help once I try it all out, considering I'm only 14 and never got the chance to learn BASIC. Once again, thanks a ton, long responses are always a treat.EDIT: It is highly unlikely that my 'scope has been modified. When I opened it, there was a strong seal holding the metal cover to the front panel.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 28, 2018, 03:40:54 pm
content: Here is the original FlukeView Software attached:DownloadDownload the two zip files:- FlukeView_Software-1.zip- FlukeView_Software-2.zipUnpack each ZIP file seperatelyYou will end up with 2 RAR file:FlukeView_Software.part1.rarFlukeView_Software.part2.rarUnpackUse WinRAR to unpack both filesuse password: "HighVoltage"You will end up with 1 ZIP file:FlukeView_Software.zipunpack this ZIP file and you will get two folder:- FLUKE- Fluke Ver 2 updateINSTALLCopy the folder "FLUKE" to to C:\Ending up with:C:\FLUKEStart the SETUP.EXE in the "Fluke Ver 2 update" folderIt will search for the FV33WIN.EXE in the "C:\FLUKE" folder and then update to v2 full versionDone!

author: HighVoltage
author_rank: Super Contributor
timestamp: January 28, 2018, 03:42:04 pm
content: Here are a few screen shots of the software:

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: January 28, 2018, 04:17:12 pm
content: Thanks! May I use a 3 wire null modem cable to connect?

author: HighVoltage
author_rank: Super Contributor
timestamp: January 28, 2018, 04:55:53 pm
content: Quote from: AutogolazzoJr on January 28, 2018, 04:17:12 pmYes, you can do that.Make sure to use the settings in the screen shot for 3-Wire setup.UTILITY > RS232 SetupThe PM3394B was the most stable one that supported full 38400 baud speed.On the PM3394 and PM3394A you might need to slow down to get good results,especially when you want to save and retrieve SETUP Data.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 04, 2018, 07:01:28 pm
content: I was waiting for my null modem cable and rs232 pci expander to motherboard header adapter when I got impatient and simply connected the scope rs232 directly to my motherboard with little jumper wires; it worked on the first try. Thanks to all who helped.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 04, 2018, 09:40:32 pm
content: Sometimes the backup memory fails and my settings are lost. Is there a fix for this.Also, I am looking to replace the bulb, possibly with an led bulb. Any drop-in for this? What bulb size?

author: DerKammi
author_rank: Regular Contributor
timestamp: February 05, 2018, 07:05:15 am
content: Quote from: AutogolazzoJr on February 04, 2018, 09:40:32 pmDon't know about the back up, eneloops will be my next try. Nothing wrong with mine after I replaced almost all the el. caps and some cracked MKT's.For the bulb I found one ebay advert which is gone now but it was the following description:Quote

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 05, 2018, 02:58:02 pm
content: So, using rechargeable batteries will help with the backup?What are mkts?

author: HighVoltage
author_rank: Super Contributor
timestamp: February 05, 2018, 07:35:46 pm
content: A new pair of alkaline batteries will last normally 10 years in these scope, unless they are bad types and leak.I still have some of these PM3394B with original Philips batteries and they are still OK.

author: DerKammi
author_rank: Regular Contributor
timestamp: February 06, 2018, 01:37:08 pm
content: Quote from: AutogolazzoJr on February 05, 2018, 02:58:02 pmMKT capacitors, 2 of them on the digitizer board had cracks in them.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 07, 2018, 07:02:23 pm
content: It happened again today. I turn on the scope, I checked both battery voltages (two of them, each 1.6v) and when I turned it on, I get a NO BATTERY BACKUP and all my waveforms are lost and I have to refocus and autocal the machine. Is there a problem with a certain chip? Something I can replace and easily have it not randomly clear the backup? I have a pm3394 with the extended memory (options for 1 channel 32k aquisition). I have looked at grumpydoc's teardown (https://www.eevblog.com/forum/repair/pm3394-can't-communicate-with-ufo/) and haven't found what could go wrong, because I know the two ROMs on the cpu board are flash chips.Any help?

author: grumpydoc
author_rank: Super Contributor
timestamp: February 07, 2018, 07:20:15 pm
content: Dodgy connection?

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 07, 2018, 07:30:57 pm
content: I'd rather it not be, I was about to break out the soldering iron! The connection is most likely the case, the terminals are dark and grimy. I will go test that out.

author: DerKammi
author_rank: Regular Contributor
timestamp: February 07, 2018, 07:38:24 pm
content: Clean them up with demi water. The have seen leaked batteries then, acid is still doing its thing I'm afraid after a long time.Mine were still covered in battery acid when I bought the scope and are dark black. But after 8 weeks it holds up nicely these days.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 07, 2018, 07:53:50 pm
content: Wups, my memory was erased as well, they were only slightly dark. Vinegar cleaned them up fine. We'll see how it performs in the following days.

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 08, 2018, 02:10:51 am
content: Definitely a problem here. One of my saved waveforms was erased to a blank trace. Perhaps a problem with one of the two flash rom chips?Thanks

author: HighVoltage
author_rank: Super Contributor
timestamp: February 08, 2018, 08:12:14 am
content: The scope is extremely sensitive to a voltage drop from the batteries.Make sure the contacts are really clean.I use very fine sand paper and then apply some silicone grease.Or test the wires to the battery compartment

author: AutogolazzoJr
author_rank: Regular Contributor
timestamp: February 08, 2018, 02:02:04 pm
content: Sure, butg I highly doubt that the batteries turning off for a microsecond was able to wipe one waveform but leave all the settings and other waveforms intact. Is there ANYTHING else that can cause this problem?

author: HighVoltage
author_rank: Super Contributor
timestamp: February 08, 2018, 02:06:12 pm
content: May be something wrong with the memory itself.I never had that specific problem.

author: Howardlong
author_rank: Super Contributor
timestamp: August 17, 2022, 06:46:39 pm
content: Quote from: grumpydoc on January 28, 2018, 01:46:50 pmApologies in advance for necroposting...I now have two PM3394Bs.The first I coincidentally bought just prior to Dave's video, and it came fully loaded with Math+, extra memory, GPIB and the External connectors, but sadly CH2 & CH4 have substantial offsets in digital mode (analog is fine), indicative of a broken hybrid on the A8 board.Anyway, another PM3394B turned up on eBay a few days ago for a reasonable price, so I ordered that one too with a view to using it as a parts scope for the first one: the eBay description detail was rather sparse, so I was expecting the worst, and it was already clear from the pics it didn't have GPIB or the External connector options. Well, despite my prejudged misgivings, it turned out to work perfectly, and furthermore it's a far cleaner unit than the first, and, like the first unit, it also has the extra memory and Math plus. Even the graticule illumination bulbs are working.Both units have the same firmware versions (EXT-V4.0, 1996-10-02, UHM-V1.0, UFO-V2.0), but the first one has 640KB ROM with the second one having 512KB ROM, presumably due to the GPIB being missing.So the question is, do I take the working A8 digitiser board out of the new clean scope to fix the fully loaded but aesthetically displeasing first scope, or move the appropriate boards, daughter boards and connectors from the grotty example to the clean unit?Bonus question: is there any significant advantage to updating the EXT ROM to 4.1?

author: grumpydoc
author_rank: Super Contributor
timestamp: August 21, 2022, 09:15:56 pm
content: Must admit I once thought all PM3394B's had GPIBJust transfer your CPU (A3) board to the new 'scope.