I'm running out of space, so I bought a Ferguson 204T!
I know, I really shouldn't be buying anything else, especially not another telly! But I went out doing the weekly shopping trip to Grantham on Saturday, we always take a wander into town for a coffee and some cake (a much needed requirement to be dragged round Sainsbury's!), and we walk past Notions antiques centre, and more often than not, end up wandering round it! This time, as I walked towards it, there staring at me across the street, was this Ferguson TV sat outside the shop on a table! Well, it's not every day you walk past a 405 line telly outside a shop, so I went straight to it. I half expected it to have a silly price on it, something daft like £75... No, it was worse! So much worse!! £29.... It just had to be affordable didn't it?! Never mind, I thought, maybe someone will buy it whilst I'm having coffee... Of course, they didn't, so I had to! I took it away for £25, not bad I thought. The only major snag about it is the woodworm damage, which could potentially still be active. Maybe that's why it was cheap?
On getting it home, the first job was to de-bug it, so out came the chassis, nice and easy on this, take out the 2 screws from the chassis, remove the controls from the front and sides and the whole thing including CRT comes out. Don't forget to disconnect the speaker though! I dusted it out with a large paint brush, then assessed the worm situation. The cabinet is quite well eaten, but still structurally sound, I had to go and buy some more worm killer at this point, as I'd used up my last can on the Bush record player. The cabinet was soaked thoroughly in the stuff, as well as having it injected into any holes with a syringe, just to maximise the coverage. Anything that does eat it's way out should come into contact with the stuff, and won't last long after that, hopefully!
Looking at the chassis, it looks in good order, no rust, a couple of valves have bent pins, and one in the tuner has got terrible wind! I'll have to check the correct valves are in the correct places before any attempt at power application, I'm not sure there should be a PC88 in the socket near the back of the chassis, especially not with 1 pin bent in such a way it doesn't go into the socket! Hopefully the CRT will be a good one, no way of knowing yet, I can't do my Megger test on it, as my Megger is currently knackered!
Despite the worm, the cabinet is in really nice condition! The original finish looks good, with only 1 nasty scratch down 1 side, which looks quite recent. I wonder where it's been languishing all these years?
Whilst it was apart, I gave the tube face a wipe to get rid of the sooty marks, and also gave the implosion glass a quick wipe with a mucky rag. Improved it's 'curb appeal' no end! So there's another winter project.
That Fergy doesn't look too bad and still looks to be largely in original unmolested condition save for the polo on the dropper. Once that worm killer has done it's job you could always fill the holes with melted dark scratch cover wax. Fingers crossed the CRT is OK, the rest of the chassis should be straight forward.
I have an older sibling of your set the 998T which has the same cabinet style but is BBC only with a 12" roundy CRT, it works really well and gives a smashing picture.
Good luck with your set.
Definitely no PC88 in that....it's a UHF RF amp so probably about 10 years after this set was made....!
Tuner valves V1=PCC84, V2=PCF80
I'll have a good nosey at it, I'm not entirely sure what that odd valve was now! I'll have to look again. It wasn't in the tuner, it was on the main chassis right near the back centre. It also had one of it's pins bent 90°, no idea what someone has been up to in the past! Whatever it was they were doing, I guess the set didn't work afterwards.
Till Eulenspiegel said
Two years ago I serviced the 21" version. Link to the UKVRR: https://www.vintage-radio.net/forum/showthread.php?t=119613&highlight=Ferguson+247T+21%26quot%3B+TV
I remember you getting that set! I'll be reading your thread to see what interesting faults I'm likely to come across, from a quick glance, looks like I'll be fighting hidden Hunts Mouldseals mostly!
Hopefully I'll get chance to pop the back off again later today, see what that valve actually is! I know it was a PC something..
Nice project for this winter, but get the worm sorted out. There appears to be a soft valve in the tuner, the getter looks white.
Congratulations on sorting out the Bush RP, they did sound good when new.
You're sure it's not a PCL84? That would make more sense, either as part frame osc./frame output, or audio amp./output.
But..... You have the 'map' there, shouldn't that tell you what's meant to be in that location?
Oh, and it's not unheard of to find valves with pins nipped off when no direct replacement was available, but one bent over would be very odd - either a careless job, or desperate bodge?
According to r-type.org PCL84 is a general purpose triode/video output pentode, so though I was probably a bit inaccurate above, it is still a likely contender.
The 204T was introduced in 1955 and the Mullard PCL84 came along in 1958. The first UK made set to employ the PCL84 was the Ferguson 406T.
204T chassis layout plan and valve voltages. V6 (PCF80) pentode is the video amplifier and the triode section serves as part of the frame oscillator. V14 (ECL80) is the line oscillator. Cross coupled multivibrator, feedback is between the screen grid of the pentode and grid of the triode section. Sawtooth drive from the pentode anode to the grid of the PL81 via a 0.001mfd capacitor. Sync separator is V16 (EF80), check the 0.1mfd grid coupling capacitor for leaks.
I don't know why I was thinking PC88 yesterday when I posted! Turns out though, I do have several NOS ones in stock... The actual valve in the telly is the PCF80 in V6's position, so it is correct after all! Just really badly fitted...
The EF80 behind it also had a bent pin just like this one, I've managed to straighten them both without cracking the glass, we'll see how long they last. The other PCF80 in the tuner was full of air, took me a while to find a replacement in my valve pile, but I have found one and swapped it. The duff one was cracked across the base, and you guessed it; because of a bent pin!! What the heck has someone been doing to this poor thing?! Luckily, they haven't played with the tube!
After all that, I decided to give it some mains, via the variac and isolating TX. All the valve heaters light, the mains filter cap went fizzzzzzz............. and smoked a bit, time to get the snippers involved! After that, nothing was happening, so I croc-clipped the meter straight onto the red wires on the smoother, fired up again, got a big fat nothing! There is no HT at all. Looking at the state of the mains dropper resistor, it's going to be something to do with that. There's a polo mint lashed onto it, and 2 other RS resistors tacked on behind the mains selector panel. The polo gets hot, but the other 2 stay stone cold. Looking at the circuit, it's going to be either R123, R124, R125 or R126 causing the lack of HT. I did try it on all 3 settings of the mains voltage selector, and still nowt, so that's more pointing to R123 and R124.
After a quick test earlier, it has been confirmed that R123, R124, and R125 are all OC! I think I might just remove the whole thing and replace it with a metal plate with some of those metal clad resistors fitted to it. I'll see what I've got kicking about.
The beast has been woken from it's slumber!
After working out the dropper has mostly expired, I had a good dig around in a pile of big resistors that I've recently been donated, found some that were near enough the right values, soldered them together and croc-clipped them into circuit.
I had the meter clipped onto the smoother and applied some mains via the variac. The heaters lit and I could see the voltage begin to rise on the meter! I'd done something right at least... With about 150v going in, I was getting 83.6v HT, and I could hear some humming coming from the speaker. I wound up the variac a bit and could hear a faint and slightly strangled sounding line whistle! Fiddling with the controls varied it, but nothing on the screen. I pressed the Hz button on the meter and discovered 50Hz on the HT, so the smoother isn't in good shape!
I croc-clipped in a replacement and fired it up again, this time the HT shot up over 150V, not much else was happening, not even the previous strangled line whistle. I thought it best to give it some more volts on the variac, I could only go up to 200V max, as that was what I'd set the voltage selector to on the TV, once wound up a bit the line whistle suddenly started loud and clear, and noise could be heard from the speaker. A quick twiddle of the brightness produced and almost frame collapse on the screen! First light at last.
I connected up the Aurora and tried tuning to channel 4, nothing... I turned up the voltage on the variac again, and that bought in some signals, I could hear vision on sound over the 1K tone. The frame collapse had begun to open out a bit too, revealing a garbled test card. I could also hear the line stage trying to lock to the signal, so the sync stage is doing something too.
All in all this set looks like it'll restore well, everything is working to an extent, the tube is nice and bright too, which is a bonus, you never know when buying a set if it'll be any good.
I'll add some photos later 🙂
It's certainly surprised me at how little of a fight it required to get this far!
Here's the pics I promised earlier!
Please excuse the bodgery, and also don't try it at home!
HT with dead smoothing cap
First light after replacing (well, bodging in..) the smoother
Bit more HT!
Something daft, using a mirror to see what the picture would be like, if there was frame scan! Hold the mirror so you can see the line in it, then rotate the mirror back and forth rapidly to 'scan' the picture, this is the reflection of the screen. It's best to use a small mirror for it.
The picture after the frame scan opened up all of it's own accord.