1974 Philips N1500: Finally!

Hi Chris.

A good working N1500 is a pleasure to watch. They give very good results indeed. The heads are delicate so be careful, I do know that you are anyway. I've not seen a 1500 for years and I'll be watching this with interest.

Good luck.

The Philips N1500 has this evening arrived in the "crustytv" workshop, delivered personally by Luke (Lukeg83), many thanks Luke and it was a pleasure to meet you. I'm absolutely over the moon to have finally obtained one of these 1st gen domestic home video recorders and one which on the surface, seems to be in excellent condition. For me this now makes my collection of VCR's complete. Failure to stop now would only result in never ending collecting and I would be swamped (see here, towards bottom of page for VCR's) much as I already am with televisions.

The history of this VCR? Its sat in Luke's wardrobe for the past 20 years, prior to that owned by Luke's place of work, the media lab at Lancaster university. 

As mentioned above the VCR is in overall very good condition but is suffering from the usual Philips belt rot. This manifests itself in the rubber belts turning to black gooey tar. Some of the goo is on the pulleys and a lot of it has ended up on the PCB where the belts came to rest then disintegrated, a bit of careful cleaning to remove the residue will be called for. I've sourced an N1500 belt kit from Austria and its currently on its way, should hopefully be here before Christmas.

Those that know the N1500 will be aware of the spring tensioned "dial-cordesque" head/drum lacing, its typical Philips crazyness and by all accounts the most troublesome element of this VCR .  A very vulnerable failure point being the plastic cog on the motor often breaks up due to forces repeatedly exerted upon it. On this machine I believe this has been fixed in the past as I appear to have the old one in a bag of bits and the one fitted looks quite fresh (not discoloured). The tensioned cord is my main worry, it would appear on initial sight to be intact and in place, however its not something I'm either familiar with or know at a glance, if truly OK so some reading of the manual (its in the library) and studying of that mechanism and how it should be laced will be required (diagram below).

The final photos below show the underside of the deck. This to me is very reminiscent of the G6, the main chassis hinges down giving good access not only to the print side but also to the component side. On the print side like the G6 there are many many point to point wires, all single core and prone like the G6 to popping off, great!.

With the chassis hinged down you can see the eddy current braking system, the large head drum servo and smaller capstan servo ( shiny discs) with the associated coils which generate the alternating magnetic field.

I'll set about cleaning up the belt residue( you can see the shiny black poop stripes in the last photo), fit the new ones when they arrive and lubricate the areas of the mechanism that need it. As a parallel task perform some cold checks and tests in the power supply section of the circuit before introducing it to any voltage.

And so the journey begins......... I've no idea if this is going to be a success story or not, whether there are any fundamental faults that cannot be resolved that will prevent it from working once again, spare parts are non existent so I can only hope fate smiles on me, wish me luck!

It’s very clean inside, lots of Lockfit transistors, have to see if they have survived. Lockfit seem a mixed bag for reliability after 40 odd years.

Brings back a lot of memories Chris. Also the death of a good friend and engineer who worked with us apprentices, he was ex Philips and trained on the N1500, lovely guy and unbelievably helpful, he passed away when I was just time served in 1975, still sadly missed.

I never worked on these early machines or the subsequent 1700 so I shall be following with interest. Now I did know someone who was fully conversant with these. He retired from Philips around 1994 during the first round of redundancies and was still around a few years ago although he's well into his 80's by now if he's still with us. I'll try and find out if he's still around.

The N1500 was my first VCR, it was a few years old at the time and had a broken head chip. A new drum and a full setup the machine worked faultlessly. Picture quality was amazing, downside was the short playing time. Next was a N1700 which I had for a few months, both went to my brother Paul in Leicester. Knowing Paul he most likely still has them, sadly we don't keep in touch due to a rift caused by our late mother. I then bought a new NEC PVC740 beta machine.

I've read some incorrect online sources that state the N1500 is purely TTL. However despite the device appearing to be packed to the brim with lockfits, I have found a couple of I.C's, just not in the usual DIL package but contained within a 10 pin TO-5 package.

The first time I came across the use of these early I.C's was in the 1968 1st gen Baird M718 CTV for signals processing,  I wondered at the time if it was perhaps the first use of an I.C in a British manufactured television.  If you've not already seen it, I covered this type of package in an I.C. blog article you can read here.

It was a common package for some linear IC’s Mullard TAA350 and TAA 570, RCA used the style with CA numbers. 

The RBM A823 chassis used the TAA350 for sound demodulation, this IC requires a detector of some form RBM used slope detection if I remember correctly. Pye used the TAA570 in the BW 169 chassis also as sound detector but the detector was built in quadrature type.

The Baird in 1967 was probably the first but others were not far behind. Baird took a lot of circuit ideas from RCA, RCA were also using this style of IC around that time.

It was probably used for digital IC’s, no reason not to.

Hi.

Of course there were dual and quad transistor TO5 packages as well. I well remember Bi-Pak or was it Bi-pre-pak selling IC's in the late 60's via Practical Wireless, I actually bought some way back when I was a kid but never got them to work!!

I have just been looking through the Data library and CES Link 49 as a photo of a N1500 on a test jig to give easier access. Its made from Steel but a wooden one could probably be made quite quickly.

I'd forgotten about the wealth of CES Link service advice in the library, I'll have to seek out all the tips pertaining to the N1500 series.

For the benefit of guests reading this thread and members not yet having gained library access, here is the jig Frank is referencing.

figures show Philips N1502 fitted to the jig.

The belt kit has today arrived from Germany, only took five days which considering its during the Xmas post period is very good. Now the preparatory work and clean up can begin prior to fitting and testing.

I send quite a few small parcels to Switzerland, about one a month for the two grandchildren there, 5 days is about normal.

I have never worked on Philips VCR’s , not that much experience on any for that matter, I will be watching the thread.

Posted by: crustytv

here is the jig Frank is referencing.

Pity I didn't rescue any of those. Back in 1987 when the workshop closed, no-one ever thought that 1500's and 1700's would be collectable..... Some of those were made up in our plant department.

You're a brave man Chris, BTW do you have any prerecorded material for both the 1500 and 1700? 

If you do have problems with the lacing cord and gearbox some ingenious person has come up with a fix here, a bit crude but it seems to work.

I did hear of the clock controls becoming live in early 1500s, I'm presuming the affected machine would have all been recalled?

Posted by: Jayceebee

[...]  BTW do you have any prerecorded material for both the 1500 and 1700? 

Hi John,

Yes I've sourced 3 x LVC60, 1 x LVC90, 1 x LVC120 and 1 x LVC 150 tapes also a couple of cleaning tapes which appear unused or at least very little used. Some tapes have labels stating Star Trek (kirk) TV series, Starsky & Hutch etc but most have nothing written so its a mystery and intriguing to ponder what might be on them.

I've no idea if they are recorded on VCR or VCR-LP, I have this N1500 and two N1700 machines so the plan is to attempt to get all working then find out what's what with the tapes, a not insignificant task but it should be fun and educational.

Posted by: Jayceebee

You're a brave man Chris

Not at all, some might say ignorant of the task ahead and they're most likely correct, however that's never stopped me before and in some respects its an advantage to not know the full extent of the pain ahead.  ? 

Posted by: Jayceebee

If you do have problems with the lacing cord and gearbox some ingenious person has come up with a fix here, a bit crude but it seems to work.

Yes indeed I found that and was very impressed with the ingenuity, really hope I don't have to go to that extent though.

You'll be looking forward to the eddy current servos, nice old technology actually.

And that's where having known good test recordings are a huge advantage. You would be chasing your tale if you had both record and play faults and no test tapes. 

Are replacement pinch rollers available?

Posted by: Jayceebee

Are replacement pinch rollers available?

Short answer is no, spare parts other than belt kits seem non-existent, a thorough scoring of European sources might yield something but unlikely. If a problem then refurbishment or ingenuity with a substitute rubber will be required.