Author Topic: Philips PM3340 2Ghz Digital Scope: Good/Bad?  (Read 17429 times)

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Offline SaabFANTopic starter

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Philips PM3340 2Ghz Digital Scope: Good/Bad?
« on: January 05, 2016, 07:27:53 pm »
Hello

I just came across a Philips PM3340 2Ghz Scope on ebay LINK: http://www.ebay.de/itm/FlukePhilips-PM3340-2GHz-Digitalspeicher-Oszilloscope-mit-FFT-usw-/272096155168
It apparently is in working condition and because I personally like Philips instruments and at least one of my projects has already taken me beyond the capabilities of my PM3320A, this one is rather appealing to me, but the question is: Are these scopes good/usable and what would be a good price? The PM3320-Models regularly are sold for about 200€ on ebay (+/- 30€). So I guess that this one will be in the area of 250 to 300.

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Online TurboTom

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #2 on: January 05, 2016, 08:31:18 pm »
This is really a special RF instrument - sequential sampling only (means it can only display periodical signals) and 20µs/div slowest horizontal deflection, so it's no use for audio and similarly "slow" signals whatsoever. Don't buy it if you're looking for a general purpose o'scope...

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Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #3 on: January 05, 2016, 08:36:51 pm »
Hi,

I have one and it is indeed best suited for RF. Only 50ohm input and low sampling rate. It is however a beautiful instrument for debugging transmission lines. It is heavy and fully documented.
 

Offline Hydrawerk

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #4 on: January 05, 2016, 09:54:12 pm »
How old is that?? Late 1980s?
Amazing machines. https://www.youtube.com/user/denha (It is not me...)
 

Offline SaabFANTopic starter

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #5 on: January 05, 2016, 10:01:57 pm »
Yes, I think so.
I have a PM3320A here, which I actually use more than my Rigol DS1054Z because it's somehow more intuitive to use^^
According to the datecodes, most chips in it are from 85 to 88, with at least a few made in 1990 and also some made all the way back in the late 70s (programmable Timer from Intel).
So far, these scopes seem to be of pretty solid construction. I sold another PM3320A a while back with a defect I couldn't fix and the buyer told me that he got it running again after some additional tinkering.
I don't know if this also applies to the PM3340, which is probably using quite different components to achieve the higher bandwidth.

Offline pascal_sweden

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #6 on: January 05, 2016, 11:25:09 pm »
Can't this scope be used as a general purpose oscilloscope in the lower bandwidth range?

Does it provide sampling memory? How many seconds can be sampled at given bandwidth?

How is the FFT functionality?
Can it act as a basic spectrum analyzer up to 2 GHz?
 

Offline Wuerstchenhund

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #7 on: January 06, 2016, 06:38:39 am »
How old is that?? Late 1980s?

We got several Philips/Fluke PM3320, PM3323 and PM3340 scopes back in 1988/1989 shortly after they had been introduced.

I liked them a lot, they were easy to operate, reacted quickly to user input (and offered a numerical keypad!), and proved to be extremely reliable. PM3320 and PM3323 quickly became my day to day scopes back then. At least until the faster HP 545xx Series came out  ;)

Can't this scope be used as a general purpose oscilloscope in the lower bandwidth range?

To some very limited extend only, and even then it's a very poor general purpose scope because of its timebase limitation, the 50ohms only inputs, and because it's no real-time scope. As others already stated it's a sampling scope made for RF analysis (primarily eye diagrams), something which back then was not possible to do with real-time scopes because their sample rate was too limited.

These days the scope and its technology have long been obsolete. 2GHz real-time scopes have been available since the end of the '90s.

Quote
Does it provide sampling memory? How many seconds can be sampled at given bandwidth?

The PM3340 (as the PM3320 and PM3323) has four separate sample memories of 4kpts each which means you can store four different waveforms.

As a bonus, the PM3320/PM3323/PM3340 are 10bit scopes.

Quote
How is the FFT functionality?

Very slow, and really very basic. FFT was an option on PM3320 and PM3323 (if I remember right it came standard on the PM3340), and if my memory serves me right it used some 500 points or so. Back then that was great. 27 years later it simply isn't.

Quote
Can it act as a basic spectrum analyzer up to 2 GHz?

Not really. FFT in those scopes was meant to look at the frequency components of a repetitive signal, and the (by today's standards) painfully slow processor and the low memory present severe limitations to its performance.
 

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #8 on: January 06, 2016, 09:05:57 am »
To give an impression how the sampling is implemented, just a part of the input circuit. (unfortunately hardcopy A3, difficult to scan the full page) and the detailed characteristics from the service manual.
 

Offline SaabFANTopic starter

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #9 on: January 06, 2016, 11:07:53 pm »
Interesting... Do I understand this correctly: The Scope is sampling/Down-Converting the Waveform in the analog domain before it is sent to the hybrid (P2CCD-Chips quickly store the Sample-Points and then the 50kS/s ADC digitizes these Samples) acquisition-system? That's quite a long way for the Signal from the inputs to the screen :)

I also read that the PM3323 used at least on some boards SMD Electrolytic Capacitors, which are prone to leaking/drying up because of all the heat that is generated by the 500MS/s acquision-System. Is this also the case in the PM3340?

Offline dom0

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #10 on: January 06, 2016, 11:28:15 pm »
In a way, yes. It's basically the same tech analog sampling scopes used since the 1950s or so, just that instead of projecting the dot-pulse-train onto a XYZ display device an ADC digitizes them.
,
 

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #11 on: January 07, 2016, 08:52:10 am »
OK,

As it was a long time ago that I had a peep insight, I opened it up and made some pictures. Luckily I did so, because I found two boards that were not seated correctly.
An overview after opening the top(mostly digital processing) and bottom(analog parts)

Clearly visible are the delay lines constructed out of coaxial lines

The card cage is well organized and it is easy to find their function(third image)
 

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #12 on: January 07, 2016, 09:00:54 am »
Most of the digital boards consist of through hole components
Images;
A11 ADC board
A9 DPU board
A8 DPU control
A7 IEEE
A6 micro processor board
A5 Logic management
 

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #13 on: January 07, 2016, 09:07:28 am »
Images;
A4 Display memory
A3 Display control
A2 Display DAC
 and the display board(forgot the final amplifier)
The power supply is huge and is completely discrete
 

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #14 on: January 07, 2016, 09:18:22 am »
The analog part is most interesting(bottom of the instrument
The input section is well shielded and the delay line takes quit some space
After opening up the trigger front end amplifier more RF parts show up and this unit is perhaps the most complex part
The trigger processing is complex. I expect due to some special functions(transmission debugging)
The main signal is straight forward and built with through hole components.
The only shielded box I didn't dare to open up(seems almost glued) is the actual sampling unit

Finally just some RF signal to show the screen in action(needs some vertical alignment, still on my to do list)
One of the very nice features on this scope is the green auto button.
My use is mostly the investigation of SDI signals
 

Online nctnico

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #15 on: January 07, 2016, 09:48:02 am »
I think I see a capacitor leaking on that HF board. I'd look into that!
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #16 on: January 07, 2016, 12:16:33 pm »
Tnx!, yes it does look suspicious. that unit was anyhow very dirty with all stuff coming from beneath as well due to missing feet.
 

Offline SaabFANTopic starter

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #17 on: January 08, 2016, 01:07:57 am »
That golden RF-Board loooks magical :D
There seems to be quite a bit more SMD-Stuff in that device than in the PM3320A, where SMD-Components can only be found on a few daughter-boards and there are no electrolytic capacitors on those.
Both that and the fact that it is basically only usable for RF takes it out of my area of interest. Although it would be interesting to look at the waveform of the VCO I'm trying to build in my Spectrum-Analyzer project^^

What I find interesting is the fact that the Firmware on the processor-board seems to be interchangeable between the three scopes from this series (PM3320A, PM3323 and PM3340). Do you have any means of reading these ROMs and uploading the Firmware somewhere?
Btw. does calculating an FFT also take about 15 to 20 seconds on your unit as well? Once I activate certain math-functions, like FFT or Max/Min-Mode, the scope gets pretty sluggish.

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #18 on: January 08, 2016, 02:36:04 pm »
Hi Saabfan,

I uploaded the firmware of the EPROMs to KO4BB. The four EPROMs are Intel 27c010 200V DIP package (128k x 8) and yes, the FFT takes some time ~10 sec on average however no sluggish experience on my side.
Currently recapping some boards. Like nctnico noticed on the RF trigger input board, all 10uF SMD caps need replacing(other values and caps appear within specs after checking them with DE5000)
 

Online nctnico

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #19 on: January 08, 2016, 03:19:58 pm »
Make sure to wash the boards. Ethanol and StMarc (paint cleaner on the Dutch market which is similar to simple-green cleaner) are good solutions for getting rid of electrolyte.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline dom0

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #20 on: January 08, 2016, 03:33:14 pm »
Holy paint cleaner?  ;D
,
 

Online nctnico

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #21 on: January 08, 2016, 03:36:49 pm »
Yes, and angel approved!
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline wazoo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #22 on: November 02, 2016, 01:15:09 pm »
Hi there

Does anyone knows how to repair this oscope ??
I have received one PM3323 and first impression is that it has "big noise" on both channels.
I powered ON and then set channel A and B as GND input (no DC, no AC)

Normally I get a plane line , but in this scope it shows full scale noise.
I have read that is a tipical issue, but can not find who explain what capacitor needs to be changed.

Does anyone knows about ??

Thank to all


Apologize for my english  :o
 

Offline Emo

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #23 on: November 02, 2016, 03:01:30 pm »
Hi Wazoo,

Is it possible for you to include a picture of the screen with the noise? Have you tried to display a known source by using the green "auto" button?
Because of the modular way these scopes were built, the source might be isolated by disconnecting the path between modules. Do you have any documentation of this scope?

Eric
 

Offline SaabFANTopic starter

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Re: Philips PM3340 2Ghz Digital Scope: Good/Bad?
« Reply #24 on: November 02, 2016, 04:22:57 pm »
Hi Wazoo,

Is the scope you have by any Chance from eBay in Germany? I saw one there last week and i noticed that the seller had turned down the intensity for the Traces but there was still some of the noise visible in the pictures.

Repairing the noise-problem is pretty straigt forward: Replace ALL electrolytic capacitors. Especially the SMD-Types will have dried out by now, which introduces all kinds of noise into the supply-lines.

There could be other problems with the unit, but the noise-problem is a known issue with the entire PM3323 series. Just make sure you don't damage the pads when replacing the SMD-Caps.

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