I'm rather impressed with Philips - where did they learn to design like they did?

[ParcGwyn]

My PM3217 was purchesed for £15 with a sticker saying spares or repair, after over a year of ownership I have not been able to find anything wrong with it. As a result the service manual hasn't been needed.

Dave
GW7ONS

[MrBungle]

Yours was £5 more than mine!

I did a thread here on it https://www.vintage-radio.net/forum/...d.php?t=127596

[Argus25]

"I'm rather impressed with Philips - where did they learn to design like they did?"

I have quite a bit of Philips lab gear. One good example being the PM5519 TV pattern generator and other Philips generators. The theoretical design, practical implementation, manual and documentation is outstanding. Philips had a way of doing things, including making most of the components themselves, all which had a characteristic "Philips look". They were very advanced with ferromagnetic cores,transformers, IC's & transistors, audio products such as ceramic magnet speakers, capacitors,resistors and the list goes on.

Tektronix achieved a similar degree of excellence.

I might point out though that these remarks relate, on the whole, to pre-1995 technology. After that lab equipment designs were not really intended to be as easily serviced and maintained and as a result the documentation/schematics deteriorated badly. The items became "throw away" and the company's M/O was to provide service contracts & guarantees and replace the entire instrument within a calculated improbable failure window. Much less emphasis on repairs and spare parts backup & documentation.

Also the opportunity to repair a piece of apparatus with a generic part (for example a 74 series logic gate) declined due to the use of custom programmed devices such as FPGA's, CPLD's, micro-controllers etc and no access to any original manufacturer's programming software & files.

Looking back at this old gear, especially in the 1970 to 1985 time frame, one cannot be anything other than inspired by it. And I take my hat off to the dedicated professional engineers who set such a fine example in instrument design & construction. The first step along the road to even getting close to this sort of achievement is to notice and pay attention to what they did.

However, some engineers working in today's business environment have been set other goal directives, such as "equipment life cycling" where items must not last too long, or be supported to long, just like the now unsupported windows platform I'm using to type this note.

[mhennessy]

Originally Posted by MrBungle

Incidentally does anyone know if Philips did a 100MHz bandwidth unit in the same form factor as the PM321x series? I'm hitting the 7ns rise time on this unit regularly and have to keep the Tek around now for those jobs.

You want 50 more? 3217 plus 50 gives the PM3267

http://www.radiomuseum.org/r/philips...cilloscop.html

We have one here - it's nice, but still has the same 10kV PDA, so isn't as crisp and sharp as the later 3055 series...

BTW, I think your comment about SMT in the PM3055 is correct for the earliest variations - I forget the exact details off the top of my head - but most of the ones I've seen are SMT-heavy. We still have the service manuals here, so I can double-check if needed.

If you want MHz from Philips, I recommend the PM3295. Absolutely lovely - good for 350MHz, and really nice to drive. 25kV PDA IIRC. I prefer them to the hallowed Tek 2465B series - much nicer user interface IMHO, and easy to work on. 350MHz not enough? The A model went to 400MHz.

Also keep an eye out for the later Combiscopes. I have one of the more basic ones (100MHz, 2 channel), but they went to 200MHz and 4 channels. The digital stuff isn't a patch on a modern Rigol, but occasionally useful.

[MrBungle]

Originally Posted by Argus25

Looking back at this old gear, especially in the 1970 to 1985 time frame, one cannot be anything other than inspired by it. And I take my hat off to the dedicated professional engineers who set such a fine example in instrument design & construction. The first step along the road to even getting close to this sort of achievement is to notice and pay attention to what they did.

That's exactly my thought on this, somewhat better described!

Originally Posted by mhennessy

You want 50 more? 3217 plus 50 gives the PM3267

http://www.radiomuseum.org/r/philips...cilloscop.html

We have one here - it's nice, but still has the same 10kV PDA, so isn't as crisp and sharp as the later 3055 series...

BTW, I think your comment about SMT in the PM3055 is correct for the earliest variations - I forget the exact details off the top of my head - but most of the ones I've seen are SMT-heavy. We still have the service manuals here, so I can double-check if needed.

If you want MHz from Philips, I recommend the PM3295. Absolutely lovely - good for 350MHz, and really nice to drive. 25kV PDA IIRC. I prefer them to the hallowed Tek 2465B series - much nicer user interface IMHO, and easy to work on. 350MHz not enough? The A model went to 400MHz.

Also keep an eye out for the later Combiscopes. I have one of the more basic ones (100MHz, 2 channel), but they went to 200MHz and 4 channels. The digital stuff isn't a patch on a modern Rigol, but occasionally useful.

Will keep an eye out for the PM3267 - sounds spot on. My PM3217 is far sharper than my Tek 475. Perhaps a PM3055 is an option...

I looked at the PM3295 and the first picture I saw of the guts brings the phrase "once burned, twice shy" (literally):



I owned a DS1054Z for about a month and a newer TDS2000 series unit and I just can't do the digital scopes. Must have lost a good £250 on the purchase of those versus the sale price as well. They are horrible from a user interface perspective. As long as I have a delayed sweep I'm good and all my use cases are covered. It has been costly and time consuming learning that however.

[mhennessy]

What that picture shows is the original Philips power supplies, which were pretty quickly replaced with something sensible bought in from one of the big PSU manufacturers. Those are very reliable.

The PM3267 is subjectively less sharp than the PM3217 because of the extra bandwidth, but only slightly so. It's a very usable 'scope. If we ever throw ours away, I'll give you first refusal

[MrBungle]

That's good to hear!

Many thanks - will likely take you up on that offer if the time comes

I am starting to become a retirement home for scopes. And I'm happy with that

[Vicboduk]

Another Philips user here… However I recently needed to repair my PM5326 RF generator.
To my great surprise the fault was probably due to a production error many years ago!
The fault presented as 50Hz ripple on the output (pic 1). Straight away I thought of a PSU problem.
The circuit shows that all d.c. supplies except for the +27v line are derived from bridge rectifiers. So why was the ripple not at 100Hz?
Sure enough, one diode within the bridge (ref: 401) had failed. After replacing the bridge I then checked the ripple on the input reservoir for the 5.25v regulator. (pic 4)

Then I saw it – had C524 had been fitted the wrong way round? – Surely not? (pic 2, look closely at board marking)

I was fortunate to have access to another PM5326 to compare with, which confirmed that C524 had indeed been fitted incorrectly. (pic 3)
Voltage checks also confirmed this.
I’m amazed that generator had worked for so long before something failed. It just goes to show how innovative Philips design was, it even works when it shouldn’t!

Vic

[MrBungle]

That's actually quite funny! Usually your average electrolytic would inform you loudly when this happens. I remember the same fault in an industrial computer power supply many years ago. A large Sprague powerlytic blew out and filled the entire chassis with fluff. New trousers for all of us.

[The General]

Yet another Philips user.... My PM3219 scope came from the local tip. Sat on top of a set of drawers. £10 the chap wanted for it, got it for £8. Got it home & it worked fine & still does.
My PM5324 RF sig gen came from the NVCF a few years ago for £15. Nice & cheap I thought but when I got it home I found the dial just wouldn't line up with the internal crystal calibrator... that's why it was cheap... Well Philips had used a simple but ingenious method of keeping the dial needle in step with the tuning cap by fitting a string of little nylon balls along the dial cord which registered with recesses around the edge of the pulley on the tuning cap shaft, so acting like a chain. Simple, does the job. I soon discovered someone had been in there before me & had gotten the cord (chain) one ball out. Ahhh.... Fixed that, worked perfectly. Use it still.
Now, if I could just find a PM6303 LCR bridge....
I've always been impressed with some of Philips' circuit techniques from the valve era, positive & negative feedback tone controls, hum cancellation by NFB & I have a couple of their early stereo radios.
Philips' portable audio was nicely designed both from an electronic & aesthetic point of view through the 50s, 60s & 70s but after about 1980 the cabinets became more plasticky & there was a noticeable cost cutting element to their design. Wasn't just Philips alone to be fair.
Mark.

[MrBungle]

I looked at a PM6303 on eBay a while ago to measure random variable capacitors and homebrew inductors but alas I had no money available at the time. I got this instead in the end (Leader LCR-740) which I am rather satisfied.

[Argus25]

I have the PM5326 RF generator like the one on the photo by Vicboduk. That generator has been invaluable for calibrating and tuning up communications radios. One interesting part of its design is that it contains an LSI frequency counter IC made by Intersil. I decided the way there were made they could be "kept going forever" I collected some spare conter IC's just in case.Most of the other parts would be easy to get.

There are also some interesting and uncommon (now) IC's used in the PM5519 TV pattern generator, these are the OQ5502 and OQ5501 used in the sync generator and color subcarrier generator, the OM320 used in the RF circuits and either the TCA820 or TDA0820T used in the RF modulator. It pays to collect a few spares for these, just in case.Most of the other IC's are 74LS series and easy to get.
However, these units have been very reliable, just some power supply issues with the bridge rectifiers needing replacing. The blue Philips electrolytics also seem very long lasting in these units.

On the other hand in the equipment a generation earlier, like the PM5334 sweep generator, the electrolytics give big trouble. They short out, taking out the smaller transistors in the regulator circuit. I have attached a photo of one that shorted in my PM5334, but another one did it too.

[Maarten]

OQ IC's were always uncommon as they were custom designed and not available outside the factory and the service departments. OM are mostly hybrids and theoretically a bit more common but Philips didn't sell too many of them to outside customers either.

P.S. Obviously the German made 'high quality' capacitor wasn't. Philips should have used their own instead of (I think) Frako.