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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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8th Oct 2016, 8:05 pm | #1 |
Octode
Join Date: Jul 2006
Location: Solihull, West Midlands and Beaford, Devon
Posts: 1,626
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Fun and Frolics with a Friendly Philips
Hi everyone.
As I haven’t posted much here of late I thought I’d put a very quick write-up of a monster Philips set with a tiny tube that my pal Tone and I sorted out over the course of a weekend. The set, a Philips 6027A, came from our own Brian C. who kindly parted with the set for a very reasonable sum of money some months back – along with an accompanying Philips 6028T screen onto which the set would soon project a picture. I am a bit of a fan of projection sets so the prospect of getting this great lump working was rather alluring and it didn’t take Tone’s normal threats of menaces to get me to make a start on the old girl. On rumbling the set through to the workshop it was immediately obvious that this wasn’t going to fit on the bench – as I initially (and possibly rather ridiculously) thought. Turning the set on its side revealed a metal grille and a foil-covered hardboard bottom cover - making the chassis underside totally inaccessible from the bottom – so the chassis had to come out. And so did the enormous wooden control panel. And the tube. And the plethora of interconnecting cables. Once all this lot had been dumped on the workbench, the chassis was given a cursory inspection. All present and correct – at first glance anyway – so the work began in earnest. First of all were the usual HT smoothing caps, which were duly disconnected from the set and reformed using my death-trap reformer. They all reformed remarkably quickly with no signs of any problems at all and so they were re-soldered into the circuit. Next the tube, scanning coils, focus coil, control panel and everything else were connected up and power was applied. Valves flared into life and two minutes later there were signs of life; a nice healthy sounding line whistle and the characteristic 1KHz buzz from the EHT module. A short while after that there was a loud bang and some savage sounding crackles coming from the EHT box. The set was quickly turned off and the screen around the EHT was removed to see what was amiss. When the set was turned back on, the same nasty arcing noises were heard but this time sparks could be seen inside the Mullard EHT can (through the glass insulators on the top) as well as sparks coming from the ECL80 EHT oscillator valve. A second later and the EHT went off. The chassis was then up-ended – not an easy task with the dozens of cables going everywhere – and the trusty Hameg scope was brought into service. On examination, there was no oscillation happening as there was no voltage on the ECL80’s pentode-section anode connection. There was HT at the top end of the oscillator transformer primary but nothing on the bottom end. When measured, the transformer showed itself to have an open-circuit primary. A quick rummage in the loft found another suitable transformer, which was soldered in. The oscillator valve was then removed from the set and checked on the Mullard valve tester for damage; the tester then well and truly condemned the valve. A new valve was slotted in but further examination was required to find out what had killed it, and presumably the transformer, before the set was switched on again. To test the Mullard EHT unit, it was removed from the Philips and connected up to a handy White Ibbotson projection set lurking downstairs, which showed it to be perfectly good – so it was resoldered into the Philips set again. After a small amount of further examination to find out what might be causing all the merriment in the EHT section, it was discovered that the earth-return from the tube aquadag to the chassis had not been connected – which turned out to be what was causing all the fireworks and distress to the oscillator valve and transformer. On connecting up the earth cable and switching on again, a very dull blurry fuzz was discernible on the screen. The line looked good but the frame wasn’t giving much output so a small frame-cap-changing spree commenced. When the set was switched on again, the frame was looking much better but the picture was terrible and there was virtually no line sync. This was traced back to an open-circuit resistor in the anode of the video output valve. Replacing this and connecting the trusty Aurora brought up a much nicer high-contrast picture with good line sync. After another small selection of nasty black pitch caps were replaced with an equal selection of those nice bright-yellow Vishay custards, the set was almost ready to be put back together. There were still a few odds-and-ends to sort out though – The first of which was the aerial socket which had been previously snapped off and a coaxial wire soldered in its place leading to a Belling-and-Lee socket on the bottom of the set. The broken socket-remnant was drilled out and a new one was screwed in and connected in its place. The last job was to fix the tape-measure on the front of the set. The tape-measure is a retractable flexible plastic line which is used so that the screen can be located the correct distance from the set, but the one on this Philips set wouldn’t retract. The small unit was removed from the front and given a good blow-out (filling the room with white dust) and a very light dab of oil was applied to the retractor mechanism, which sorted out the problem completely. Lastly the chassis had to be reinstalled into the cabinet – again, not an easy job – and one which takes about 20 minutes if nothing goes too badly wrong. The problems are that the cables and plugs all have to be plugged in and routed correctly – something which takes a good three hands to do, especially as the cables are really only just long enough. Also, added to this is the 13-channel VHF tuner which has to be removed from its mount and rested on the chassis until the rest of the unit is correctly installed into the cabinet and then the tuner can be screwed back onto its rails again. Once the set was all back together, the set was tested at normal brightness (projection tubes produce X-rays when run at high brightness and so the brightness must be kept to a minimum when running the tube outside its normal enclosure). The set now produces a lovely picture, although the EHT regulation isn’t as good as the White Ibbotson downstairs so the picture size and focus changes if the brightness or contrast are turned up too high – but this is pretty normal for most projection sets. Anyway, not a terribly exciting restoration to be honest – but an interesting set – so I thought I ought to write something about it. Thanks everyone. Kind regards. From Mike. PS. Excuse the projected picture in the photo - The proper screen is downstairs and far too heavy to lumber up in to the workshop so my noticeboard had to do as a rather poor substitute.
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G7TRF Last edited by Mikey405; 8th Oct 2016 at 8:24 pm. Reason: Spelling... |
8th Oct 2016, 8:27 pm | #2 |
Hexode
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
Posts: 279
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Re: Fun and Frolics with a Friendly Philips
Wonderful story and a great write up, thanks Mikey
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Classic TV Show Theme Tunes |
8th Oct 2016, 8:59 pm | #3 |
Nonode
Join Date: May 2006
Location: St Albans, Herts, UK.
Posts: 2,193
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Re: Fun and Frolics with a Friendly Philips
A nice weekend's work. Well done both!
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All the very best, Tas |
9th Oct 2016, 12:48 am | #4 |
Pentode
Join Date: Jan 2015
Location: Wakefield, West Yorkshire, UK.
Posts: 151
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Re: Fun and Frolics with a Friendly Philips
What a nice result and as ever a good write up Mikey
Marc. |
9th Oct 2016, 6:54 am | #5 |
Rest in Peace
Join Date: Jun 2004
Location: Burghfield, Reading, Berkshire, UK,
Posts: 1,055
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Re: Fun and Frolics with a Friendly Philips
That is excellent, Mikey. I knew that it was going to a good home but I didn't think that it would be up and running in such a short time - I had it for years!
I assume that the wooden slats have been glued back into position on the cabinets as they were the only furniture-type problems! |
10th Oct 2016, 7:56 am | #6 |
Octode
Join Date: Jul 2006
Location: Solihull, West Midlands and Beaford, Devon
Posts: 1,626
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Re: Fun and Frolics with a Friendly Philips
Hi NTSC, Marc, Tas and Brian.
Thank you for the kind comments. I realise it was a bit of a dull restoration (in fact it was scarcely more than a "repair") but it's a really fun (and completely impractical) set and I enjoyed getting it going immensely. Brian - It was a set I'd lusted after for many years after having seen one at the NEC so I was very grateful to you for selling it to me at a very reasonable price. As for the slats, I have glued the loose ones back on the projector itself but the screen is behind the sofa in my lounge and not terribly easy to get at just at the moment. I will get them sorted out once I've extricated the screen though. Thanks all. Kind regards. From Mike.
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G7TRF |
10th Oct 2016, 1:47 pm | #7 |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
Posts: 2,965
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Re: Fun and Frolics with a Friendly Philips
An excellent repair and restoration and a good read as well.
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Simon BVWS member |
11th Oct 2016, 11:28 am | #8 |
Octode
Join Date: Oct 2005
Location: Wimborne, Dorset, UK.
Posts: 1,407
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Re: Fun and Frolics with a Friendly Philips
Hi Mike,
Great story, well done to you and Tone! I Always like to read a telly write up! By the way, what was the loud bang? was it just the arc? Cheers
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Lee |
16th Oct 2016, 10:40 am | #9 |
Octode
Join Date: Jul 2006
Location: Solihull, West Midlands and Beaford, Devon
Posts: 1,626
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Re: Fun and Frolics with a Friendly Philips
Hi Lee.
Thank you for the kind comments. The bang was really more of a "crack" and it was something arcing over in the EHT box. It made me jump - to say the least. Thanks Lee. Kind regards. From Mike.
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G7TRF |
16th Oct 2016, 10:45 am | #10 |
Octode
Join Date: Jul 2006
Location: Solihull, West Midlands and Beaford, Devon
Posts: 1,626
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Re: Fun and Frolics with a Friendly Philips
Hi all.
Just a last quick word on the Philips. Below are some pictures of the set boxed up and working with Brian's original Philips 6028T screen. Apologies for the focus in the photos - My camera doesn't focus too well in the pitch black with the flash off - and you need to be perfectly still because of the relatively long exposure. The picture is actually a lot better in real life. (Enough of the excuses...) If anyone would like the original large versions of the photos then they can be downloaded from the link below. Included in the ZIP file is the service manual if anyone is interested. http://www.oldtechnology.net/misc/Philips_6027A.zip Thanks all. Kind regards. From Mike.
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G7TRF |
16th Oct 2016, 12:42 pm | #11 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
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Re: Fun and Frolics with a Friendly Philips
Hi Mike,
flat screen TV fifties style. I have the Philips 600A in the workshop. While the projection set which is the subject of this discussion provides a really big picture the 600A has screen which is smaller than a 17" CRT. DFWB. |