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  #1  
Old 03-31-2012, 03:12 AM
Glenz75's Avatar
Glenz75 Glenz75 is offline
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Philips 23 inch 1962 b&w TV set

Hi guys, here is something a little different, this is another New Zealand 1960's made Philips vintage black and white TV.

This has been pretty much cloned from a European design, I've seen very similar versions of this on Marcels TV Museum website. Here is the link to them - http://www.marcelstvmuseum.com/photoalbum55.html

The NZ collaborated chassis was known as the 'S8' and was used in various models. This one here is an early example and in typical Philips style live chassis with series heater chain and two printed circuit boards.

These sets were highly regarded by serviceman, were pretty reliable, used good quality resistors/capacitors and performed extremely well. They did have their run of the usual faults but on the whole a lot better than some other brands of the time.

I have three very tidy examples and this is the fourth one so decided to get it going to use in the workshop, as the cabinet is a bit marked and have plenty of spare parts for these so don't really mind using it as a 'hack' and its always nice to have something to throw things at to relieve frustration fixing other things! (Probably won't, but the thought is nice...)

Unlike all the other S8's I've seen or worked on this one still has its original line output transformer and virtually no dry joints on any of the valve sockets and hardly any damaged or lifted print on the boards which leads me to think this hasn't not had much use but it did take some work to get it working properly.

After replacing a busted EF183 and boost cap that had split open I applied power via the variac and raised it to 200 volts and waited....nothing much was happening so increased the mains some more...got humming from the speaker and that was it, did a quick measure of the B+ rails, which were all present but it no other real signs of life...hmm a bit odd as these usually were a bit more lively than this!

Started with the horizontal drive and found not much happening there so replaced the PCF80 and things started happening we now had EHT and a line across the screen! Done some more poking only find the vertical oscillator wasn't working either, another PCF80 later and now had a full raster.

But it was rather dead in the tuner/if stages with a signal fed in just a blank raster...Found the 2nd IF EF184 had no emission and a short, so replaced it, still nothing....I then checked the PCF86 mixer and PCC198 RF amp in the tuner and found the PCF86 to be gassy, it lit up pretty colours on the the AVO and got pulled out pretty quick.

So in went another PCF86, now we had something but still no picture just flashes of snow/lines and I just happened to knock the board around the 1st IF valve and that made the picture go nuts, so some prodding indicated something was loose here. A look at the board revealed broken tracks around the IF can and a shoddy past repair to the print.

I fixed all that up and tried again, there now was steady snow, so I rotated the tuner to the desired channel for the RF modulator output...still nothing... then the picture started flashing/pulsating every few seconds...What on earth was going on! I could now smell something getting hot and happened to glance down to tag strip on the tuner where the B+ supply resistors are and saw the 560 ohm glowing red so lunged at the kill switch on the variac!

Ok so buy this time I was starting to think nasty thoughts about this set (Mental images of pulling it off the bench by the power cord and laughing madly as it hit the floor!)... This was meant to be a quick fix and now turning into a rather drawn out affair.

I checked for shorts to that stressed 560 ohm resistor to ground and found nothing so removed the tuner and pulled the covers off to investigate inside and a rather burnt looking resistor to one of the valve pins was staring me right in the face, ah-ha! The circuit called for 3.3k and this little charcoaled delight was reading 220 ohms. I wasted no time in replacing it, reconnected everything and applied mains while monitoring that supply resistor and to my disgust the 3.3k started belching smoke within about a minute along with the poor 560 ohm lit up like a tiny bar heater again

This thing was really starting to test my patience so I walked away and left the thing alone and just as well as that evening my wife went in labour with our second child so that put a stop to TV tinkering for the time being.

Once back on the job I went over my work done on the tuner and could not see or find any shorts within the tuner. I did have some spare tuners but my gut told me not to replacing the tuner only as a last resort. Then I had a thought about the tuner valves again wondering if the replaced PCF86 or the original PCC189 was faulty? So for a laugh I put in another PCC189 and tried it to no avail so I put in another PCF86 and tried it again...This time the voltage wasn't dropping and it was stable...so I waited expecting smoke, then sound burst forth from the speaker and then my test pattern DVD appeared on the screen! HORRAY!

So what the hell was up with that so called 'good' PCF86? A quick test of it again revealed several shorts, so why did it decide to die? Probably to irritate me which it did but then maybe that 3.3K resistor was already faulty and maybe have damaged the valve? Who knows? Talk about a double edged sword with the tuner fault!

The set was now giving a pretty good picture apart from flashing white lines intermittently and varying brightness accompanied with a slight hum bar going through the picture. A check of the filter capacitors indicated they were all low so I replaced them along with some other electros around the vertical and audio output stage. With all that done, the hum bar was gone and so was the excessive hum in the audio too, but the flashing was still there, which turned out to be one of the PCL85's in which the triode section does the clamping for G1 of the CRT which was faulty. The pentode section does one half of the push-pull for the audio.

Since this thing seemed to be suffering from 'dud valve disease' I went through and checked them all and found the PCL85 vertical and the other PCL86 audio both to be very weak and a couple of other PCF80's that were a low but the rest checked out ok.

All that was left now was to clean all the controls and check and adjusted the boost voltage down to where the picture is still acceptable width wise but this also extends the life of the flyback in these and adjusted and picture geometry/horizontal/vertical oscillator presets in which both were pretty close and replace the mains filter cap.

So now after the so called 'quick fix' the final result is a very nice working Philips S8 and it does have a stunning picture. Lets hope it keeps behaving itself from now on.

Thanks for reading, if you've gotten this far Enjoy the pictures.

Cheers
Glen.
Attached Images
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File Type: jpg IMG_4857.jpg (100.7 KB, 45 views)
File Type: jpg IMG_4864.jpg (130.0 KB, 38 views)
File Type: jpg IMG_4865.jpg (100.4 KB, 50 views)
File Type: jpg IMG_4868.jpg (82.0 KB, 45 views)
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Last edited by Glenz75; 03-31-2012 at 03:17 AM.
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  #2  
Old 03-31-2012, 08:50 AM
dieseljeep dieseljeep is offline
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I enjoyed reading your entry. I never worked on a single set that had that many problems. The set really turned out great. At least the CRT was good.
P.S. Congradulations on your new family member!
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  #3  
Old 03-31-2012, 09:39 AM
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Phil Nelson Phil Nelson is offline
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Thanks for the interesting story. It's fun to get a peek inside a set like this and note differences from the typical US TV.

I think you should save this TV for your second child. "Dad was fixing this one on the day you were born."

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html
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  #4  
Old 03-31-2012, 10:03 AM
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Kevin Kuehn Kevin Kuehn is offline
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Nice work! I find that cabinet style very attractive. Also that test pattern indicates the sweep is about as perfect as one could hope for.
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  #5  
Old 03-31-2012, 05:20 PM
Glenz75's Avatar
Glenz75 Glenz75 is offline
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Quote:
Originally Posted by dieseljeep View Post
I enjoyed reading your entry. I never worked on a single set that had that many problems. The set really turned out great. At least the CRT was good.
P.S. Congradulations on your new family member!
Thanks, yeah this one sure did have some problems... I don't recall any other sets I've worked on being as bad as this to get going. What was surpirsing is how all the those tubes were bad, considering the set had been laying dormant for years, but going by how untouched everything was, maybe the original owner just used it until it failed completely then stored it away?
We had a baby girl who is very cute!

Quote:
Originally Posted by Phil Nelson View Post
Thanks for the interesting story. It's fun to get a peek inside a set like this and note differences from the typical US TV.

I think you should save this TV for your second child. "Dad was fixing this one on the day you were born."

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html
Hi Phil, yes very true about Bethany being born the same day this set was being fixed, should definitely keep this one then! Same can be said about US TV's, find your sets always fascinating, especially the vintage mono sets and colour roundies!

Quote:
Originally Posted by Kevin Kuehn View Post
Nice work! I find that cabinet style very attractive. Also that test pattern indicates the sweep is about as perfect as one could hope for.
Thanks! These give a good picture and geometry is pretty much spot on with this model. Philips were always pretty advanced in their designs hence why this chassis goes so well.
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Old 03-31-2012, 09:36 PM
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bgadow bgadow is offline
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Nice to know that we suffer the same trials when fixing up these sets, worldwide! Good write-up, and that looks like a well built TV. A keeper!
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Old 04-01-2012, 10:32 PM
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Electronic M Electronic M is offline
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I tend to work on older sets so take this advice with a grain of salt, but I think it is a good SOP to test tubes before first power up to prevent future headaches.
I always try to keep tubes in mind during trouble shooting as they can conk out at the most confounding times. To illustrate this I have a Silvertone roundy that I tested the tubes and got a poor raster on before repair. I had to change some parts in the horizontal oscillator and messed up it's frequency. Well that set likes to eat damper tubes (by way of shorting) when ever the horizontal frequency is too far off. It took me months after the original work to figure out that it had killed the original damper. After all of that I decided to go through the horizontal adjustment procedure and discovered that when I had momentarily ran the set with the horizontal frequency off it had eaten another damper! This set also conked out again a while back due to the damper loosing emissions to the point of testing marginally after prolonged warmup (it would test at the lower end of good as soon at it warmed up, but slump soon after).
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