B&W TV Rainy Sunday entertainment, Bush TV22 corpse
Gave the speaker a little tarting up today, removed the cone, cleaned the gap out as best I could firstly with some P400 wet and dry paper, then half a roll of insulation tape to get all the muck out. Then scrubbed all the loose rust on the frame, wiped it over with IPA, then gave it a coat of paint. It’s ended up satin black, just because it was close to hand! Tomorrow I’ll put the cone back and see if it sounds any better.
A lot of the fixings have cleaned up well in the vinegar too. The lopty has been removed for safe keeping, apart from the cracked pitch, it looks ok, the laminations are fairly rust free, the most of it is where it fixes to the chassis, it has the ‘T’ shaped laminations, which have rubber sleeving over the ends, this has gone rock hard, so I’ll replace it with a few layers of heat shrink.
Speaker is done! I gave it a run directly from the headphone output of the iPad before sticking anything down, it sounded good, No voice coil rubbing!
I then stuck the spider down first, with 3 shims cut from bog standard A4 paper put into the gap with the voice coil.
That was left overnight, and tonight the shims were removed, and the speaker tested again, all sounding good, so then I glued the edge of the cone back to the frame.
Tip: don’t pull on the dried bit of glue in your wood glue bottle… yes, it went everywhere…
after much cleaning up the glue had dried enough to give the speaker a run with a bit more power, from a little 7w solid state amplifier, the results are excellent! Speaker sounds nice and clear with no voice coil rubbing or rattling. Just need to dig out some felt to replace the dust cover now.
I have got quite good at rebuilding speakers too. I wish I could find a way of reliably removing the cone edge from the frame though. I have tried soaking the glue with white spirit, petrol etc but it makes the paper very delicate.
Yes, it would be nice to be able to remove it without damage, most of the speakers I’ve worked on have been so rusty that the cone had already detached from the frame, or just rotted through at that point. This one was still in fair condition with just a little rust, I ended up just cutting it with a scalpel as close as possible to the edge. That left it with a very close fit that took the glue well. Other speakers in the past I have had to make a new edge to stick down to the frame, normally just a ring of plain paper will do, so long as the rolled edge isn’t missing or damaged. If the worst comes to the worst, it might be possible to buy a foam surround and glue that on! That’s something I need to do to one of my old Ekco’s, as when I repaired that speaker I stiffened up the rolled edge and now it sounds awful!
Lopty drying antics…
With the speaker looking and sounding good, I thought I’d better do something else! Turned my attention to the lopty, as it seems the norm to at least try and drive off any moisture that may be buried deep in the windings. I have never really tried this before, except on the GEC, and it didn’t want to know! I started by measuring the windings to see what was connected where, then used my croc clip leads to connect the whole lot in series. The bench supply was slowly wound up, I ended up with both outputs in series, which gave me 50mA with it maxed out (2x 18V 5A). That got the temperature up to just over 32 degrees, which I left for a couple of hours. I got another power supply involved after that and got it up to 65mA, which got the temperature up to just over 60 degrees, I left it on like that all day Thursday, and you could see the pitch had changed from a dull greyish black to a more shiny black, and had become soft, but not to the point of dripping off, I also placed some silica gel packets around it, and a bit of kitchen paper over the top to keep some of the heat in!
that’s going to be it for a week, as I’m on holiday at the lovely Anderby Creek now!
Back from holiday 🙁
I did another shot of lopty warming, hopefully it should be enough! I also managed to break the heater winding, because the EHT wire had gone rock hard, it split the cardboard bit with the 2 connectors in half and ripped the wire off, so I removed it completely, cleaned off the pitch, very easy when heated, stuck the cardboard bit back together, reattached the wire, glued the cardboard tag board to the former of the overwind, then rewound the heater winding, I lost a turn because the wire ended up a tiny bit too short, hopefully it won’t matter too much! If it does I can always pull it all off and do it again with new wire. I stuck heatshrink over the top of it to cover it and minimise corona discharge. I also knocked off some of the pitch from the overwind (I know, clumsy or what!) so I melted some of the bits over the naked bits. The EY51 has been refitted, it nearly didn’t fit! I think I put the tags back too close to the output from the overwind. I also added some heatshrink to the ends of the laminations where there was originally some rubber sleeving that had gone hard. It’s all ready to go back on the chassis now, including the brackets that have been de rusted.
I have also started cleaning up the main chassis, so far it’s coming up ok! I need to find some EHT wire to replace the rock hard old stuff.
amazingly, the old rubber wire to the CRT base is in great condition! It cleaned up nicely, and is still soft! It’s normally crispy and falls to bits!
I haven’t forgotten this!! It’s just taking forever to clean it up, the corrosion on the aluminium parts is nasty, so I’ve taken to wet sanding it! I give it a blast of foam cleaner, then a quick scrub with P400 wet or dry, it takes off the lumpy bits of the corrosion and stops it shredding my kitchen paper when I use it to wipe up the dirty foam cleaner after it’s done it’s thing. The worst part for corrosion so far has to be behind the serial number plate, which took some work to get it off, the screws were stuck, but brute force and ignorance paid off, and the screws finally came undone. There was a thick white crust behind it, which had to be scraped off with a screwdriver! The plate, which is brass, was ok, just tarnished, silver polish sorted that out.
The mains wiring from the dropper to the switch has begun to crack a little right at the switch end, so I’m probably going to have to replace it just to be safe. Shame really as the rest of the rubber wiring is in great shape!
I may have got a little distracted from the Bush over the last week, a Sony FH-215R Hi-Fi from 1987 arrived, so that took some of my attention getting it clean and running, I might do a write up, but I doubt anyone would find it interesting!
last week, a Sony FH-215R Hi-Fi from 1987 arrived, so that took some of my attention getting it clean and running, I might do a write up, but I doubt anyone would find it interesting!
Lloyd, if you can spare the time, please do consider writing up your 80s Sony Hi-Fi repair.
I only said to a member last week via a pm, in that message they stated they had a project, but were uneasy about writing it up on VRAT in case purists gave them a load of grief.
My response to that being, members should seek reasons to post at VRAT , rather than find reasons not to! The former does not help VRAT, the latter harms it, activity breeds activity, and we surely need it.
In the past, we/I, have been accused of being a TV only site, my response has always been, that's because the TV brigade often post more of their work, than the audio boys. So I'd encourage you, or anyone, to post. 👍
I'll do a write up for it 🙂 I should have done a write up for the FH-7 of similar vintage, that had a lot of faults on it and would have been more interesting to read! Sadly I fixed that one ages ago (2014 I think!) and I've forgotten most of what I did to it..
Things are starting to take shape now! I have finally got to the point where things can start going back onto the chassis, although it still looks a mess! Especially since I took the front plate off so I could get the muck out from behind it, and make it easier to get to some of the fixings that are hidden behind transformers and the main smoother. Shouldn’t be long now before I can plug it in again!
Well, today is the day I get to plug it in again!!! I got off work early today, after working a load of overtime last weekend (Sunday working should be banned!) I now have this weekend free, and I sure need it!
so back to the TV22, I have replaced most of the waxies, just the mains filter and the big hum filter are missing, electrolytics mostly seem fine, but the 2uF ones are going to be replaced with film caps when they arrive. The resistors all seem to be within tolerance, so none have been changed. With all that done, and a bit of cleaning under the chassis, I was then able to reassemble almost everything, currently the 2 wooden side panels are having their worm holes filled, so I’m waiting for that to dry, then I’ll give them a quick blast of satin black paint to freshen them up.
First power up was nerve wracking! It all seemed to come to life, but with nothing on the screen, and a check with the EHT meter showed the EHT hadn’t come up. I turned it off and checked the EY51 and it’s winding to make sure it wasn’t playing up, but all was well there, what could it be?! Then the penny dropped, some numpty forgot to plug the scan coils in!
Round 2 was much better, it came up, EHT present, and a dim fuzzy small raster! After a bit of tweaking I had a fair picture up, I was only running on 200V at that point, so up to full mains, and I had to tweak it all again! EHT settles just under 8KV with the brightness turned down, and about 7.5KV with the brightness set about right. The tube is nice and bright, despite the partial heater short, the heater is mostly sat at 4.8V, some gentle tapping sometimes clears it, and the voltage shoots up to 6.25V, but equally it can get worse dropping down to 3.9V. The pictures fine so I’ll leave well alone! I did try rotating the tube a bit, but it’s made no difference.
The only wiring to be replaced has been the EHT lead, and the lead to the top cap on the PL38, I butchered a knackered Redifusion MK4 tripler for the wire, and I also re-used the EHT cap too, it looks quite smart I think! The wire is a bit stiff, but at least it’s not crumbling.
I’m currently running the set and it’s looking good, it’s been on for about an hour now, picture and sound are good! The lopty core is quite warm, which does bother me a little, but it’s holding stable.
I did video the first and second power up, so it may end up on YouTube.
Well, would you look at that, amazing to think it's the same chassis we all saw looking all forlorn at RetroTech 2022. Nice work Lloyd.
The tube is nice and bright, despite the partial heater short, the heater is mostly sat at 4.8V, some gentle tapping sometimes clears it, and the voltage shoots up to 6.25V, but equally it can get worse dropping down to 3.9V. The pictures fine so I’ll leave well alone! I did try rotating the tube a bit, but it’s made no difference.
I had the same fault on my TV22, (which I still have, one of only two 405 sets I kept, the other being another Bush, a TV125CU ) and likewise, no amount of tapping would result in a permanent fix. My solution was to remove the CRT from the heater chain, replacing it with a 22R 7W resistor. I then added a dedicated RS heater transformer, resulted in a nice bright raster.
Cheers Chris 🙂
it’s like a weight has lifted now it’s all back together, Even better that it still works! It sometimes gets a bit daunting when you get so far into a project, bits strewn everywhere, and wondering if it’ll ever be finished, but now the end is in sight, and I can start thinking about the cabinet, so long as the chassis keeps working!
Frankly Lloyd, you are a genius.
The true spirit of restoration dwells within you. 👍
Few more bits done, the wooden bits have been refurbished, and look acceptable, just a few more fixings to go in, they have just come out of their vinegar bath, and after a scrub have been sprayed with WD40 to keep them from rusting again. I also received the replacement 2.2uF caps, and have fitted one of them, they are very colourful! It says ‘Audiophiler kondensator’ on it, strangely it didn’t come with an ‘audiophile’ price tag! So far so good, on the meter it measured bang on 2.2uF, and the set seems happy with it. I’ll swap the one under the chassis later on today. I might take a trip to the lock up to find the other RF chassis that’s hiding in there, it has a band 3 converter bolted to it, so it’ll be interesting to see if it can be revived, maybe I’ll set up another RF source in the workshop and put it on band 3 for a change! I’ve only ever really used channel 4 on band 1, as most of my 405 sets are channel 4. Might also have a look at a tube for the GEC whilst I’m there…
It’s all coming together nicely! I have the other RF chassis, complete with band 3 converter, it’s not in bad condition, some light rusting in places, the string has snapped on the tuning, and there’s no valves. I had a dig through stores and found the 2 valves for the band 3 tuner, and the others can come off the original chassis.
Now for the really interesting bit, the cabinet! I dug out the unsuspecting victim, the very first ‘TV22’ I ever purchased,
or so I thought until it arrived, and I found this inside it!
as you can imagine, I was not best pleased at all, so the poor thing has spent most of its life stuffed in the back of a wardrobe. At least it worked I suppose, although it doesn’t work now, just a blank raster with faint hiss on the sound.
The cabinet isn’t the best, it’s cracked just below the screen, there’s a hole drilled above the screen for a magnifier, and it’s a bit dull. Someone’s painted the rubber mask gold in the past too, but I kind of like it! I will get round to doing a proper repair to the cabinet eventually.
with the imposter extracted, I fitted the cabinet onto the newly revived chassis, I had to make some adjustments to get things to line up, the hold controls still don’t quite line up, despite a couple of attempts to tweak them. The volume knob put up one hell of a fight! I couldn’t fit it with the screw in place, so spent ages trying to get the screw in down the slot, but kept dropping it, then when it did go in, it stripped the threads on the screw, so I ended up having to file it down. It would have helped if the volume pot was original, as the one fitted doesn’t have a flat on the shaft.
with that out of the way, I could then turn my attention to setting up the picture. I spent a fair bit of time squaring it up, messing with the ion trap and focus magnets until I was happy with it. I left it to run for a few hours to see how it went, and so far it seems to be ok! I’d forgotten just how much heat comes from them, but it still seemed happy enough.
there are 2 things I’d like to address, one being the lack of fly back blanking, and the other being the rubbish interlacing. It doesn’t seem to matter where the hold control is, it either has what looks like line pairing, or just no interlace. I did try something I saw on another thread, where R11 (Bush manual), 100K can be reduced in value to 10K, but that didn’t make any difference to it.
A couple of other bits I forgot to mention, I have found some felt, which I have used to make a new dust cover for the speaker, and also stuck some in the wooden feet. And also fitted the other bright red capacitor under chassis!
Forgot to say the tube has decided to play nice, the heater now sits at about 6.5V, so a little over run, and I do have the voltage tappings set to 250V. Not sure what did it, I have rotated the tube a little, but I wonder if it was when I knocked a couple of small pins in place for the RF deck mounts, the bit that goes through a bit of copper foil.. either way, it looks brighter now, even though it was pretty good before!
I knew it was going too well, turned it on this evening to be greeted by no picture… turns out my attempt at repairing the EY51 wasn’t as rock solid as it seemed, well, the glue was, but my soldering wasn’t! I set about clearing the glue out to have another go at sticking new wires on, but the evacuation pip didn’t like the heat from the iron and promptly fell off. So that valves a dud now! Never mind, new ones on order, at least it wasn’t anything more serious!
I had some fun with the ‘Thorny-Bush’ chassis earlier in the day, when I last tried it, all I got was a blank raster and faint hiss on sound, so I decided to have a go at fixing it, after a bit of digging it turned out to be a Thorn 1691 chassis, and after reading another thread about the same chassis, with the same fault no less, I decided to start poking around in the same place! I’d got the board on end ready to check voltages when all of a sudden it decided to work! Totally ruined my fun… I was about to check around C34, as it had been mentioned in the other thread, I checked anyway, it had about 4.5V across it. I then set about straightening up the picture on it, as when it had been put into the TV22 cabinet whoever did it decided to pull back the scan coils, which left an almost circular picture in the middle of the screen. After fiddling with the linearity sleeve and the magnets, a decent picture came out, to be honest, it actually looks a damn good set in its own right! Maybe I’ll build it up into something nice one day.
I managed a little more work on the old shrubbery yesterday, I went EY51 hunting, and found one! It was hiding in another Bush in a corner of the workshop, it was in the other TV22 with the dead lopty, very easy to liberate as it’s got the ceramic former for the heater winding, which just slides off, and the other end wasn’t soldered down!
So out came the chassis again so I could fit that, and now we are back in business! It’s clear now that I stuck the tags for the heater too close to the output of the overwind, it’s rather tight in there, but it seems to fit ok. Picture is back as good as it was before.
Whilst in there I fitted some new caps for the hum cancellation circuit, a .47uf and a .22uf. I don’t think it’s made much of any difference, the interlace still looks a bit iffy to me, and it still has that ‘TV22 kink’ at the top of the picture. Does anyone know what causes that kink? Also, there is a little fold over at the very top of the picture.
does anyone know what causes that kink? Also, there is a little fold over at the very top of the picture.
I could be way off the mark here, there was a debate about this type of 'kink' quite a few years ago, I cannot remember where or exactly when. I do recall it was to do with the Aurora, and its switchable equalisation pulses. As it looks like you're using a HedgHog, I've no idea if it's relevant. Does it have switchable pulses? If so, maybe try it on/off, if not, then it was just a wild, random guess in the absence of anything else to add.