#7 - Building a Philips PT8631 pattern generator from scratch

[@srenpetersen5284]

The company K&J Elektronik A/S from Denmark mentioned in the video at 4:36 was closed around the year 2002. It was coincidentally owned by my parents and I used to work in the company as a young design and production technician. We produced all kinds of custom designed inductors and transformers. I don't know how I got to see this video, but it was good fun!

[@mattstvbarn]

Oh man that is cool. Amazing to hear from you and thanks for the information!

[@IrishvintageTVRadio]

This is an amazing effort!! 10 out of 10.

[@gammaleader96]

My respect, what an absolute gem. I didn't know that Philips made some of their designs open source, very nice. I think more manufacturers should do stuff like this for obsolete gear. Great job and thanks for documenting your process.

[@NofaKingway]

Subbed for the sheer confluence of insanity and skill required of this undertaking.

[@L0wcash]

I'm impressed! All that trouble for a static image.. You sir, have an iron will! Congratulations on this next level achievement!

[@mattstvbarn]

Ah but if you look at the demos, you will see it is not always static ;-)

[@L0wcash]

@@mattstvbarn yeah, after typing that comment i did look at the demos.. Still.. You went through a lot of trouble for an ALMOST static image! Thank you for sharing your adventures with us!

[@liambradymusic]

Hi Matt, amazing Engineering well done. For what it's worth I'm a retired Electronics Engineer, Back in 1971 over 50 years ago I was employed by The TV / Radio manufacturing Company BUSH IRELAND in Dublin to oversee the introduction of Colour TV. production. I knew that Philips TEST Pattern as PM5544. The first thing I had to do was to order that Test Gear from Philips! It cost around £30, 000 a big investment in those days. It consisted of a 19" floor standing Rack with a CVBS base Band Module, a 39.5 MHz IF Modulator, and a UHF Module. All fully "BBC Standard" Quality. At peak production Bush Ireland produced about 600 to 700 FullyTtranistorised CRT Colour TV sets per week. All history now!

[@mattstvbarn]

Always interesting to hear from someone who has seen this stuff. Never found the original list price for a pm5544 before. That is interesting to hear! Also PM5544 is a common vernacular term for the pattern. Not something you will find in any official literature however!

[@videolabguy]

I notified the members of the OLDVTRs discussion forum of your project this morning (California time). They were amazed and impressed too. This is the kind of equipment that we appreciate in the group. I worked for Prime Image for many years as a staff engineer. P.I. was a maker of broadcast time base correctors and synchronizers. I was the designer (of the computer core) of the accESS 500, our video still store product of the early 1990s. That product was nominated for an excellence in engineering award at the NAB convention in Las Vegas in 1991 (if I recall correctly). What a fun industry that was back then. Fond memories.

[@janosnagyj.9540]

It's interesting that despite they used a pile of programmable devices and digital stuff, they still needed that coil magic at the end... hats off for all the effort you made on this, and a big wow that at the end you succeded! 👏

[@mattstvbarn]

Yes indeed. That is because the output of the DAC is nasty, loaded with harmonics and other unwanted high frequency components, and needs lots of filtering and conditioning. In order to produce an accurate appropriately equalised video signal it all has to be precisely adjusted.

[@cyberyogicowindler2448]

​@@mattstvbarn Such things were also the difference between audiophile and household grade CD players. My PC mainboard (AsRock ITX) produces plenty of chirping in the audio when CPU load changes - likely because the (on paper high resolution) audio DAC gets too unfiltered voltages and signals. Same mess does my Dreambox DM8000 (harddisk recorder/settop box); it mixes plenty of video signal into the analogue audio and so causes chirping/buzzing depending on the PAL TV picture.

[@gcolombelli]

It's not every day we get to see a wizard creating a new magic item, thanks for sharing this video with us.

[@gabotron94]

I'm not sure if I'm more impressed by the designs being open sourced, or by the fact you can still get those parts new

[@mattstvbarn]

All of the larger more specialised chips are new old stock. I probably should have made that clearer in the video.

[@MRAWESOME22]

Holy cow. The manual placing of all those SMT components! You must a have huge amount of focus, patience, and time. Bravo!

[@AvroVulcanXH607]

Absolutely incredible!

[@richard7crowley]

Ahem, "most recognized" is rather a function of your age and location. For those of us who grew up in the 1950s-1960s in North America, it was the "Indian Head Test Pattern" for NTSC (System-M) monochrome video. Produced in analog by an RCA monoscope. BUT, your reproduction of that circuit is truly one of the most epic projects here on KZbin. Mega-Kudos!

[@mattstvbarn]

But there is only 330mn people in the US. The Philips pattern would be recognised by around 1-2bn people today.

[@LastAwAken]

As a DIY eurorack solderer, i can say this is far beyond all the levels i can imagine. Designing 6 layer pcb, building your own inductors, altera (FPGA?) chips... It is just wow

[@KeritechElectronics]

A thing of beauty and a joy for ever. Extremely complex too! :)

[@wickie-vickesverige4995]

Wow,a lot of work and "manufacturing" them coils is quite a doing! Especially when i have only the original coils (reusing the wound wire again)and there is no margin for error! I`been doing the same when changing NTSC system M to a Pal G or to a Sécam L version of the Philips PM5534. Then repogramming the circle eprom from 525 lines to 625 lines. And because i wantd to know what would happen if i use an erased "circle" eprom.....I got a square PM5544 test pattern!!

[@zxborg9681]

As a guy who spent huge chunks of my professional career sitting in front of waveform analysers and vectorscopes, this is pretty cool. I did a few designs with those altera parts too. We used to design a lot of those tunable inductors into our products back in the 80s and 90s, tyically they set a resonant point in a tank circuit and the tuning procedure was to tune coils one at a time until notches appeared at a certain frequency when sweeping on a spectrum analyser. Ironically, the company I work for just shut down our lab and we surplussed a whole cabinet full of those coils.

[@MichaelKingsfordGray]

Yet you can't recall your real name?

[@johnrehwinkel7241]

Wow, that was an amazing build and quite engaging to watch. I love restoring old equipment, and have a lot of respect for the amount of patience and effort required to do an authentic re-creation, and the determination and drive to go through the whole process!

[@goggo-bp9oj]

Incredible engineering Matt, even though I have had years of experience in electronic servicing and TV and Radio Transmission, I wouldnt know where to start! That PCB work is amazing. Top work Matt and it works well too!

[@merlin1943]

I'm not really into analog TVs, but this build is incredible, a truly inspiring video! Thanks for sharing!!

[@SlartiMarvinbartfast]

This is true skill and dedication, I tip my hat to you.

[@ashleydawson5070]

That's awesome! If I attempted this there'd be more bodge wires than phenolic.

[@JoeMuc2008]

So satisfying to watch. You are an artist! And making it work right away with so many potential failure points is outright amazing. I could never do this.

[@mattstvbarn]

There's nothing happening here that requires magical powers! It's just a matter of going through the very long and boring process of anticipating and mitigating every possible point of failure. This is the fourth one of the modules I've built thus there has been quite a bit of practise and learning that wasn't filmed here :)

[@Jonathan.Boring]

This was honestly thoroughly entertaining- the whole trial and error process.

[@timstoffel4799]

Truly an amazing effort! I wish I had the resources to try something like this.

[@michaeloneill3380]

Unbelievably great job. Like others have commented - Amazing work!

[@emilalmberg1096]

The result surprised me!

[@shaunclarke94]

Gotta admire the dedication. Glad you had a happy ending :).

[@AnalogThinker]

Very clean and nice repro, good job Sir!

[@manatkhamya]

I think you're doing a really great job, and I think I should start building this Philips pattern generator from scratch, but I won't make you angry.👏👏

[@nikhilmulay]

This is art!

[@swp466]

Cool project! Even cooler is that we both have the same channel logo (well, very similar anyway)...

[@TheFleetz]

Bloody amazing job…..well done! 👍😀

[@igotes]

Impressive. A labour of love!

[@videolabguy]

Jaw dropping awesome! Bravo!

[@boatman323]

There’s open source projects, and then there’s….. well, off the scale open source projects!

[@davidbolha]

Amazing skills & patience & endurence to go through with it all. 😍😇😕😧😆👌

[@piledesign]

WOW....Respect!

[@Zacabeb]

Amazing work! My jaw dropped.

[@phil85813]

enjoyed this!

[@TiagoJoaoSilva]

Sorry, never heard of it. Now, the Telefunken FuBK... _(for those not in the know, public television channels in Europe would pick a single technical supplier - in Portugal's case it was Bosch, so the entire technical package, including the test signal generators, was German)_

[@mattstvbarn]

Many broadcast FuBK patterns were generated by Philips hardware including this.

[@TiagoJoaoSilva]

@@mattstvbarn oh, I don't doubt that years later they replaced the original hardware with multi-pattern generators. But for a decade after the upgrade to PAL, the in-studio cameras were Bosch Fernseh, the recorders were Bosch Type B, and thousands of TVs were checked after being repaired from the FuBK pattern transmitted while everyone waited for the daily programming to start... and since the second channel started with children programming, every kid knew the FuBK (and the 1kHz tone) very well

[@mattstvbarn]

@@TiagoJoaoSilva I wonder if you could tell us exactly what hardware originally generated the FuBK pattern in the early 1970s? As far as I know nobody has ever been able to figure that out.

[@godfreypoon5148]

Hmmm it seems to be stuck on the test pattern.

[@sdjhgfkshfswdfhskljh3360]

It is nice to have "original" equipment, of course, but I wonder if it would be easier to generate such pattern with SDR?

[@mattstvbarn]

HackTV can show an image of the Philips pattern (without the non-visible signals such as PLUGE/Anti-PAL etc). To get an output which exactly matches the original equipment, well that would be a wee bit of work and nobody has done it yet. Really it all depends on exactly what you are trying to achieve. I doubt the PT8631 will ever be fully recreated because it has a long list of niche features most wouldn't care about.

[@sdjhgfkshfswdfhskljh3360]

@@mattstvbarn so theoretically it can be done? Since you have almost original equipment now, you can try recording its output with SDR (with SDRangel maybe?) and then playing it back in a loop. If there will be no noticeable difference, then it makes sense to publish such recording, maybe someone will use it to make fully digital test signal source. _(I don't plan to do this yet, but I know that recording is huge help in such task)_

[@mattstvbarn]

@@sdjhgfkshfswdfhskljh3360 I reckon the best approach would be to take the original digital samples of the pattern (which are disclosed) and just do the same math of the PT8631's circuitry as an SDR implementation. The hard part would be all of the pattern "options", text generation, clock/date etc, then, of course, just the 4:3 pattern? the 16:9 too? NTSC? FuBK? The list goes on...

[@z1ph0n3]

astonishing

[@enojelly9452]

Do you know if there's some kind of specification for that test pattern somewhere? I found some images with which I could recreate most of the visual features (including the correct color phases, after making sure), and use that for now, but of course that does not include the anomalies and other "hidden" features that the actual test pattern generator outputs. Would be neat to have my FPGA PAL generator be able to generate a faithful one. I don't have any of the Philips equipment, and besides it would also be useful for testing the performance of own generators.

[@mattstvbarn]

The only true specification is Finn Hendil's original workings which have never been made public. The pattern is mostly the product of mathematics so there isn't true drawing of it, but of course there are descriptions of its elements as you have seen. I would recommend looking at my PM5644 emulator: github.com/inaxeon/PhilipsPatternRom It can read the EPROMs from most catalogue PM5644 models (except SECAM) and convert them into a bitmap image. It will give you a good idea of how they were originally formatted and of course all of the glorious details of the pattern are in them. Dumps of the EPROMs are in here: github.com/inaxeon/PTV_Preservation/tree/main/PM5644

[@davidholman2536]

Nice. I get test cards included with the BATC Portsdown system for digital amateur TV. So the effort made here is all the more remarkable and would make a great article in CQ-TV magazine. Do Spectrum Communications in Dorset still make their own Toko variable inductor coils? All the best David M0YDH

[@sw6188]

Is it possible to create this test pattern just as a static image with a much smaller component count, simpler board and standalone (not needing the sync generator unit)? I don't need multiple patterns - just this one, and I don't need NTSC - just PAL. Composite and HDMI outputs would be nice.

[@mattstvbarn]

Absolutely but it'd be quite a lot of work. Hopefully as a result of this open-sourcing someone will take on the challenge! I'll be the first to build one if they do!

[@jms019]

That’s Colourfield’s “Thinking of You” isn’t it ?

[@deepstonecrypt]

good work :D

[@ehsnils]

Just for the sake of it - there's another video containing the various test images used by Swedish Television throughout history: kzbin.info/www/bejne/p5qulK2chJucj5o

[@Anvilshock]

I guess "open source" means "open whether anything of this can still be sourced" …

[@miasinterestinglife]

Awesome Video!! You could try making a narrated video with some of the nerdy details (might be because I'm a nerd too and just really interested in this)

[@mattstvbarn]

Oh don't worry. I make them too. This was just me scratching the itch to make a clickbait style video for once in my life.

[@miasinterestinglife]

@@mattstvbarn oh, sounds great. I'm gonna have to look into your channel a bit more :)

[@JoshuaSzanto]

Very nice!

[@crumplezone1]

Lex Luther Level. Amazing

[@arrbam02]

Excellent work sir! How was sourcing of the big programmable chips, CPLDs possible?? These things seem to become obsolete very fast...

[@mattstvbarn]

Oh they are very obsolete indeed. MAX7K chips with old date codes are easy enough to buy. The MAX+PLUS II projects (from the 1990s) are included in that repo. From there there are a couple of options. 1) Just program some old MAX7K devices like I did. 2) convert them to Atmel ATF15xx format, all of which are still in production and can drop in place of the originals. I have tested this too.

[@arrbam02]

@@mattstvbarn nice! Hats off to the company, person who had the rights to release it like this all complete and little guesswork needed, "just" patience :)

[@queuerious]

holy cow!

[@Test-hw5fn]

Wow😮

[@RicoElectrico]

Why would they need so much programmable devices? Isn't it just a glorified (well, synced to the rest of broadcast equipment) RAMDAC?

[@mattstvbarn]

If you look at the demos you will understand...

[@Chiavaccio]

👏👏👏👏👏👏

[@namesurname4666]

music used?

[@mattstvbarn]

It is the beginning of this looped: kzbin.info/www/bejne/bIGVkKpum6aoasU

[@audiodiwhy2195]

makes me realize what bottom feeders we audio-frequency DIY folks are! Great work! What is your "test card" channel?

[@mattstvbarn]

Ah but you are forgetting something. In the RF world there is no emotion. It is all about measurable results and that makes it all a lot more straight forward ;-) there are links to the demos in the test card channel in the description.

[@razzda]

Hello. I just acquired a 5210 for the princely sum of USD 22. But no 8631 😢

[@mattstvbarn]

This is the only pt5xxx i have ever seen or heard of containing an original PT8631: vimeo.com/179068435 out of interest what options do you have?

[@razzda]

​funny thing when you look at the datasheet 8631 isn't even mentioned, only PT 8601 Analog Test Signal Generator, PT 8603 SDI Test Signal Generator (TSG), PT 8604 Multiple Parallel Black Burst Outputs, PT 8606 SDI Digital Genlock, PT 8607 Longitudinal Time Code module, PT 8608 Black Burst module, PT 8609 SDI Black/Color bar module, PT 8635 Dual AES/EBU Digital Audio Generator. Mine seems to be just the basic version, but I will open it up tomorrow.

[@razzda]

Yes I know that video regarding 5230. He is based in Denmark (like me) and used to work for Danish Broadcasting Corporation (DR). Would sure love to get hold of that one. I have PT 5643

[@mattstvbarn]

@@razzda oh you might want to watch my next video when it comes out. I will be covering the 8601 and what we can do with that :) correct it is not in the datasheet. PT5210 was the entry level SPG and officially it doesn't support most of the higher end PT863x modules. But unofficially of course they can work as I have demonstrated!

[@razzda]

@@mattstvbarn looking forward to that 👌🏻👌🏻

[@BenjaminMaggi]

Insane waw just waw !

[@vincei4252]

The most impressive thing, amongst all the other impressive things, was having a programmer that can program Alter MAX 7XXXXLC cpld's. I avoid those suckers like the plague! What's the make of the programmer if you don't mind me asking ?

[@OscarSommerbo]

Looks like a "Dataman 48UXP Universal Programmer". I just searched for "intelligent universal programmer", horrible, generic name but unique enough it turns out.

[@mattstvbarn]

Oh yes those are super annoying. Fortunately I had purchased that programmer (at significant expense) for a previous retro restoration project and luckily it supports them. In the predecessor of this they had it all JTAG programmable but in this design they used up all of the JTAG pins for signalling and as you have noticed we have the non-JTAG MAX7000E in use. It is a Labtool 48UXP as pointed out by @oscarsommerbo5043

[@vincei4252]

@@mattstvbarn and @oscarsommerbo5043 Awesome, thanks for the information. I think I'll also buy (not cheap but also not 3 or 5K) one to add to my crop of programmers. I have a stack of those LC parts and it would be nice to be able to use them despite how annoying I've found them to be. Cheers!

[@mattstvbarn]

@@vincei4252 Another one to watch out for is the old Labtool 48XP (non-USB). Exactly the same functionality (i.e. ridiculous list of supported devices) but no USB interface. I have seen them on eBay for as little as $200.

[@vincei4252]

@@mattstvbarn I tried to reply but of course KZbin deleted my comment. When you can't even discuss technical topics without a ban hammer coming out from nowhere this really shows how horrible and dystopian this site has become. Kudos to you guys that post and put up with all the nonsense.

[@SuniaKhamya]

Hi, you did a great job, you can make an original Philips circle pattern generator from scratch which you can design or reverse-engineer but I don't know where to start.

[@paulstubbs7678]

Keen deluxe

[@dv_vid]

You need to use a pick and place machine.

[@mutestingray]

Girl, what? You crazy.

[@pete3897]

Amazing achievement! But my gawd, the music :(I had to mute to watch...

[@KD2HJP]

Woah. I'm very impressed. I'm also available for adoption Have ham radio license Soldering station with heat gun Some NOS Kester solder

[@railgap]

wait, you couldn't find chokes "exactly like", or you couldn't find chokes _with the same inductance_?? You exhausted all of the usual suppliers? I find that hard to believe.

[@edgeeffect]

Oh please, do voice overs... I can't cope with "music and reading" videos.

[@mattstvbarn]

I mostly do. Its hard work and I just wanted a break this month.