First TV- Ferguson 988T

[Oliver35]

Picked up my first TV today, a Ferguson 988T. I've been prowling the internet auction sites for a while looking for a suitable set to work on, bearing in mind that I wanted a round tube set, close enough to collect (Suffolk seems curiously short on old TVs) and cheap enough for me to afford. The sets that really excite me are pre- and immediately post-war sets, but those, barring miracles, are considerably out of my price range. Fortunately I found this set only 25 miles away for £25, and it ticked enough boxes to make it worth having. It's a slightly malevolent looking thing, with that purple filter on it..
It's not in bad nick, from what I was told it sounds like it was used up to the shutdown of 405, and doesn't appear to have been mucked about with too much, nice and dusty inside.
Obviously I had to have a play when I got it home, so having checked the overall circuit resistance and given everything a look-over, I wound it up slowly on the variac, checking voltage and current as I went along. After some fiddling with noisy pots and some light tweaking, I got a nice bright scan of sorts and a crackle or two from the speaker, although there's a partial frame collapse. Since then I've tacked in a couple of replacement caps, one to replace a wax cap in the IFs that let go rather messily, and another in the frame t/b that collapsed the scan even further, so I must have upset something. I've now put it aside, as the HT smoothing can under the tube is looking less than happy, and I need to order some electrolytics to stuff it, as I don't have any suitable at the moment. I'm quite pleased to have coaxed a response out of it with relatively little tinkering, and as my Radio and TV Servicing manuals don't go back as far as 1951, I'm feeling my way in the dark a bit. I've attached some rather pale photos. Where should I look to find a schematic of this set?

[1955APREN]

Hi
thats a nice find the set uses the same chassis as the 983 but does not have the push pull sound output stage. The circuit diagram is in the Radio tv servicing book Pre 1953 vol 2. If you send me a Pm i will try to scan for you.
regards Derrick

[Heatercathodeshort]

Looks great! A nice easy restoration. Tube looks nice and bright. They perform very well. It looks like it is tuned for Wenvoe channel 5 so check this if used with an Aurora. The chassis is easily retuned. John.

[TV_Madness]

What a great looking little set. Looks nice and complete too (from where I'm sitting anyway!). I reckon that will be a cracker when it's all sorted out.

Matt

[Oliver35]

That's a kind offer Derrick, I have now managed to find a copy of the trader sheet, so no need for you to trouble yourself, I'm now well under way. Thanks John, Matt, I was chuffed when the tube came up, there's no burn and no shortage of brightness, I think it's had an easy life, as not much evidence of service work either. It seems quite a workmanlike piece of kit. It is pretty much complete, one knob missing, but the back is present and undamaged. The bottom panel is AWOL, but that's no trouble to make up.

Oliver

[Oliver35]

Thought I should pop back with a more detailed update- having got in from work, the lure of a new toy proved unsurprisingly greater than the lure of more mundane tasks, like making dinner, so I've ended up rushing the fundamentals of my evening.
Not without issue, though; now I have the Trader Sheet, I can blunder around slightly more knowledgeably. I've been working my way through the resistors and caps around the frame t/b since yesterday, having achieved nothing more than turning the partial frame collapse into an almost complete frame collapse. This evening was spent checking and replacing various out-of-tolerance resistors and still achieving precisely nothing beyond a soldering-iron burn on one knuckle and exercising my vocabulary a little. I was about to shove it all away again in disgust and make dinner, when I spotted that C56 on the trader sheet had been returned to earth, rather than its proper tag, by some dunderheaded idiot. Presumably me, as I removed it to test yesterday and then put it back in, hence the increased frame collapse.
Fortunately, that rectified, the other checks and replacements paid off, and now matters are much improved. I'm quite enjoying this TV lark..

Photos show yesterday's efforts, and subsequently today's

Oliver

[beery]

Hi Oliver,

Looks great so far.
Until you gain experience and confidence then changing one or two components at a time is the way to go.
Note that circuits from Newnes books use the same references as the original manufacturer's manuals, however the circuits were redrawn for the trader sheets and hence different component references were used.

BTW It is a great choice for a first set. Ferguson were very good at designing simple circuits to work reliably. They were certainly not high end, however it seemed that the cost of a set back then did not reflect the elegance of the circuit design. You will definitely get better results from this than you would from a GEC or HMV/Marconi set of the same age and it was probably sold at a lower price than either of those...

I look forward to the next instalment.

Cheers
Andy

[Heatercathodeshort]

Good tube. It will be a Mullard MW31-16 with ion trap. The first Ferguson receiver to employ the 1950 released series of B9A Mullard 'World Series' television valves. Absolute genius by Thorn/Ferguson.
Ferguson produced some of the very best television receivers with fringe models that surpassed practically every maker. The 988T was incredibly reliable and being a superhet could be easily tuned to any of the BBC channels. It also converted well to ITA with one of the Ferguson Band 3 tuners.

Great to see you are working slowly replacing one cap at a time. Make a note of the fault and the function of the faulty component. This will be a great help with any future restorations.

Just for encouragement I have added a picture I took this evening of a 998T in my junk collection. [Don't get too serious with it. It's great fun and after all it is only an old telly..]

The mask and the provisional service manual are FOC if you let me have your address for posting. It covers most items but not the alignment but I would very much doubt if this has been tampered with.
The mask is in good condition but will require a fresh coat of aerosol gold car spray to brighten it up, after you have masked off the screen area of course.
Ferguson also produced the 'Super Twelve.' Same chassis and model number but it had a more rounded mask giving a slightly larger picture area.
The Super Twelve can be seen on the right together with an earlier model the TRF 968T with cream mask and some octal valves on the left. The cabinet is the only thing in common with the 998T. The very best of luck with it!
PS. Excuse the hearth rug. My parents made it together in 1936 soon after their wedding. Regards, John.

[Oliver35]

Thanks for the encouraging replies! I'm slowly picking my way through, or at least through the frame t/b anyway. I've been reading my way around the subject for a long time, so have some (theoretical, mostly) grounding in timebases, although I also have an as yet incomplete set that I started building to one of W.T. Cocking's designs. One day I will finish it. The multivibrator is new territory to me, however. Notwithstanding, progress is slow but incrementally positive, not least because I'm doing little bits each evening as I get the time. Frame amplitude now seems OK, although I can still collapse the frame to about 1/3 of the screen height using the occasional controls, should that be possible? Linearity is still a little off, but good enough until I start feeding video into it. The lines are still quite discernible, so I wonder if the line t/b is running slow- I haven't touched it yet, that section is still as it came. I'll attach a couple of photos of progress below.
John, I'm afraid I can't hope for too many more restorations! TVs are large, and I live in an extremely tiny house. Unless something special were to turn up, I'll probably have to stop at this one for the time being. The plan is to do a pukka job on it, refinishing the cabinet, and keeping it in the sitting room as my only 'TV', although probably only used for DVDs, as I don't actually watch television. Your offer of the mask is a very kind one- I was going to try and repair the one on it, but I probably have enough to do as it is. I will drop you a PM with my details, if that's OK.
One thing that occurs to me as I work my way through- some components I'm tacking in as I go round, to be substituted later. I've done this with a couple of small electrolytics, replacing them with poly film caps as a proof of concept, as I didn't have any electrolytics of the correct value. Obviously the manufacturers made a specific choice here, how critical is it? Will I see any significant difference between an electrolytic and a poly cap in a given location?

Also, I should say, I love the hearthrug! I think it's a splendid thing for a couple to do after their wedding. A great reminder for them, and you. Sooner that than the wedding-list mentality of today, but that's a whole other topic.

[McMurdo]

you're nearly there. I'm watching this closely. I think you'll be looking for the next project soon!

[Oliver35]

Thanks very much! It had better be a small one.. I have a Phillips 470A wireless upstairs in need of a complete rewire and goodness knows what else that I ought to do, but I'm less excited by radio than by TV, for some reason.

I've hauled the chassis out of the TV this evening and removed the tube, so that I can clean everything up, restuff the smoothing can and sort out a couple of the preset pots. The 68K resistor between the frame linearity pot and earth was very high, which can't have helped matters, it's the only frame t/b component I'd not checked, due to its position above deck. Will post more piccies in time. I've also found some old (excuse me, vintage) NOS 470K resistors in my small stock of bits, which I can use instead of the new ones I put in. I don't really like seeing modern components under the chassis, although I know it's a thorny topic for some. Not that I'm a purist as such, I just love looking at old electronics and their soothing colour palette!

[Oliver35]

Here's another update, as I've been beavering away over the last few evenings. It's quite a satisfying project, when incremental progress is assured. I've been fortunate that I haven't (so far) encountered anything overly challenging, given the limits of my knowledge.
I've now given the chassis a perfunctory clean down and replaced the iffy 100k line hold pot with an old one I had in my ad-hoc collection of bits, which fortunately presents the same outward appearance. I also took the opportunity to check and replace the only (!) cap in the line timebase- an extremely economic bit of design. All that done I put the tube back in and tested it again, and at the moment, I'm pretty happy with where it is, although I thought there was a slight picture shift to the left, although that may just be me. Focus is hard up against the end of the fine adjustment, so I've possibly not quite relocated the tube support in the same position, although I did mark it as I took it out.

All that done, I've now put the entire chassis in a large cardboard box and tucked it safely out of the way while I turn to the cabinet. This has been knocked about a bit, with chunks taken out of the veneer on the top and front, the whole veneer edge being less than securely stuck on one side. I've so far stripped all the finish off the top and front (the top especially didn't need much persuasion) and started patching the veneer. The match isn't perfect, but I can tone the patches in to the rest of the veneer before finishing, and it was some salvaged bits that I conveniently had lying around. The sides, perhaps unsurprisingly, are simply plywood with an extra heavy coat of tinted laquer that is more or less opaque, and I have to say I don't find it an attractive solution, although I'm sure it was an expeditious measure for an affordable set. I'll see what the grain of the ply looks like and if I can tone it down to match the veneer- if not, I suppose I'll just have to paint it brown again, but I'd rather see a grain. I did think briefly about veneering the sides, but that would be a bit silly in this context.

One thing I haven't done yet is to strip back the bit of lacquer with the 'FERGUSON' script on it. At first I thought this would be easy- I've used dry fix lettering under lacquer before, and I felt sure that a set of transfers in a 'Western' style font would be OK, but I can't at present find any. Any ideas? I've found and downloaded a modern font that's a gnat's whisker away from being correct, so there may be a way of creating a transfer from this, but doing it in gold might be tricky. Does anyone know of any way of doing this?

Oliver

[Tazman1966]

Well done Oliver. You're making some good progress with this set.

[Oliver35]

Thanks! I've been lucky with it, I suspect- but I do get a bit fixated on a project once I get my teeth into it. It's cathartic.

Not much more progress today, a couple more veneer patches, and I've stripped one of the plywood sides, which will probably look OK if they're toned down to match the veneered faces. At least the plywood doesn't chip off like the veneer does..

Oliver

[Freya]

coming along nicely, it may be advisable to give the wood a treatment of woodworm preventer/killer inside before you apply the outer finish.

[Heatercathodeshort]

That is going to be a great restoration and well worth the effort. [I will be posting the bits today] The original Perspex screen filter was quite a dark almost sinister Purple. Over the years the pigment has diluted considerably especially if exposed to sunlight. John.

[mark_in_manc]

That sinister purple screen reminded me of something...or should I say...someone...


http://www.toonhound.com/edna-8.jpg

I'm not someone who gives my car, guitar, fridge, or parts of my anatomy nicknames; but in this case if your set belonged to me it would now have one!

[Oliver35]

Oh yes! I'd forgotten about her. Thanks John, that's very kind, will be a great help, especially as mine is fracturing further, having gone very brittle. Oddly enough, the implosion screen I have still retains an even and rather malevolent shade of purple, so I may swap them over- assuming the screws still move. The current one has a scratch on it though, so I'd have to see if it will polish out first.

Hoping to get some more work done is evening, but domesticity may get in the way. I've ordered some dry transfer paper for standard inkjet printers to try and manufacture a replacement logo- no idea how that will turn out, or if it will survive being cellulose lacquered, but it's worth a go.

Oliver

[Heatercathodeshort]

Metal polish wadding or T cut do the job nicely. J.

[Oliver35]

I have used that technique before, on the celluloid mudguards that used to be de rigeur for touring bicycles in the '50s. I used to start with the slightly coarser T-cut, then on to Brasso, then finally Silvo if I was being pedantic. I use the last two for finishing cellulose as well, gives a really cracking finish.

Have been trying to finish off the cabinet preparation tonight, thwarted somewhat by the innumerable loose edges on the veneer, mostly on the left hand side of the cabinet. Trying to rub down the sides without chipping the paper-thin veneer is a nightmare, I've now doused the corners with diluted glue to try and cure the problem. Hopefully the lacquer will protect them, but I've got to get that far first..

Oliver