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I must be insane! Ekco A22...

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Lloyd
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Posts: 1957
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Cheers guys 🙂

Yes the rivet situation is causing trouble, it's very difficult to even find any useful info on bog standard rivets, as it seems the expectation is everyone wants to use/buy pop rivets and the tooling, or rivets for sticking on leather things, none of which are what I'm after! I guess when Ekco made these chassis, they had a big press with a jig in it and the whole operation would have been done in seconds. For the moment, so I can get on with re-building the radio I have cheated and used some 4BA cheese head screws and nuts to attach the valve holders, with the hope that at some point I'll be able to find some nice rivets to replace them. I actually still have the rivets that I removed, and did consider putting them back in and holding them in place with a blob of solder on the back, when I removed them I only drilled a little bit to weaken the bit where its squished and then knocked them out with a centre punch. I'll keep that idea as a last resort.

There has been steady progress with re-assembly, valve holders are in place, IF transformers have new wiring and the cans have been polished, the screened lead has been refurbished with new silicone rubber wiring, the dial lamp has new wiring also. I discovered the original volume pot was knackered, the track has been too damp and has got bits of missing carbon, so it would be crackly and horrible, luckily the one on the spare chassis is absolutely fine so has been pinched for this one, I was going to pinch the mains transformer too, since its an original one, and the one the set came with is an ill-fitting replacement, unfortunately the primary is open circuit, so that's not going to happen now. I also tested the resistors in the set, a few are still nearly spot on value, but most are well out, and will need replacing, I haven't decided what resistors to replace them with yet, would be nice if I could find some that look the same as the originals, I might also have to replace a couple of the mica caps too, one of the 100pf ones was reading low Mohms on my DMM, so that cant be good!

I noticed whilst replacing the wiring that some of the old rubber stuff was actually two-tone, the wires to the choke were red/white and red/yellow, as well as some other wires were red/black, shame I can't find any new silicone rubber wiring in two-tone colours! I have gone for single colour throughout, so the wiring for the choke is now simply white and yellow, I might try a red permanent marker pen on the wire to see if I can make my own two-tone replacement!

Regards,

Lloyd

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Posted : 17/08/2019 2:08 pm
Cathovisor
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Posted by: @lloyd

Yes the rivet situation is causing trouble, it's very difficult to even find any useful info on bog standard rivets, as it seems the expectation is everyone wants to use/buy pop rivets and the tooling, or rivets for sticking on leather things, none of which are what I'm after!

Sounds like you're looking for semi-tubular rivets and rivet 'sets' - this is the tool that forms the end of the rivet.

Try http://doidge.com/original/english/semitub.html - I bought stuff from them when they were still in North London. Heaven knows where it all is though!

 
Posted : 17/08/2019 6:32 pm
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Lloyd
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Cheers for that, I’ll have a look round their site! 

Regards 

Lloyd 

 
Posted : 19/08/2019 9:38 am
Lloyd
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Time for the latest on this rather long winded project!

IMG 6854

I'm afraid it's not a very interesting update, mostly just a lot of wiring has been done, but I did clean up the mains transformer and tested it on full mains! Last time I mentioned the transformer on the other chassis was O/C, well, it turns out it isn't! It also turns out that it's not from an A22 either... I could have used it, but decided against it as it doesn't have the winding for the AZ31 rectifier, which is a directly heated type, it also doesn't have the extra tapping for the dial bulb, so all the valve heaters are wired together on a single 6.3V winding, not sure that would work without changing the rectifier to an indirectly heated 6.3V type, which I don't want to do. Strangely it does look sort of 'Ekco', it even has the mains voltage selector panel that Ekco used, but it's upside-down when on the A22 chassis! Shame, because it fits the hole perfectly!

So I've kept the ill-fitting replacement that came with the rusty chassis in the black cabinet, just because it has the separate winding for the rectifier, which measured about 6V unloaded, but did drop to about 4V with the rectifier's heater connected up, the winding for the other valve heaters gives out about 7V unloaded, and 6.4V with the rest of the valves connected up, I had a right royal lash up of croc-clip leads to do that test!

Now to the reason I call it ill-fitting, the mounting holes don't line up with those in the chassis, the previous 'restorer' had simply filed out the holes at the back of the chassis, and the holes in the voltage selector bracket, and used 2 much thinner bolts to mount it, I thought they were 6BA, but they don't fit in 6BA nuts, so they might be M3, the original bolts were 4BA. The 2 mounting holes at the other end of the transformer are about 1/4" away from those in the chassis, and so the previous 'restorer' just left it hanging, I didn't like that at all, mainly because rust had crept in between the laminations and made one side of the transformer thicker than the other that was clamped down, and also because with full mains on the transformer it buzzed like an angry hornet...

In the end I marked out the chassis and drilled 2 new holes in the right place, and used 2 of the 4BA fixings from the other chassis, which turned out not to fit through the holes in the transformer, so I drilled those out too! Surprisingly after all this torture, the transformer still works! Oh, I also had all the laminations out of the transformer and scraped the rust off with a knackered Stanley blade, then once the transformer was back together I gave it a good bit of Briwax, melted into the laminations, just makes the remaining rust look nicer.

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The last remaining problem with the transformer is the lack of correct voltage tappings! It looks to me like it's a 2X 110V windings, each centre tapped, so I've got the whole lot in series, which still only comes to 220V, probably explains the slightly too high voltage for the valve heaters. This leaves the voltage selector panel redundant, I will re-fit it to the chassis, but leave it disconnected, maybe one day an original transformer will show up! and then also pigs will evolve to have wings and fly...

I dug out my near perfect brown A22 so I could have a good look at the chassis to see what I was missing, turns out that there should be a little clamp or bush, not sure what you'd call it, that stops the dial cursor from slipping forward, and also stops you from pushing the dial and speaker grille assembly too far back and fouling on the cursor, it also has a brass domed washer under it, photo attached. I'll have to make one out of a bit of ally.

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I also had a good look at the speaker fitted, neither of the ones I have look like it, one looks like it's from a DAC90, and the other I really don't know, and neither of them work properly! So I'm keeping an eye on eBay for a replacement speaker, I have a few DAC90A's that can lend a speaker for testing.

IMG 6834

The audio output transformer is also a replacement, and it looks much smaller than the original Ekco one, sadly the one on the other chassis has been eaten by a mouse... it ate right through the edge of the primary winding, rendering it useless! So I'm on the lookout for an output transformer too.

Till mentioned poor performance of his set, so I fired the brown one up and had a good tune around with a load of test leads daisy-chained as an aerial, I was able to receive all the usual stations, but some of the weaker ones that I can receive on other sets were either too weak or just not audible, I left it playing Absolute radio for a short while, until the adverts came on! Short wave performance was good, not sure where in the world a lot of the stations were transmitting from, but there were plenty of them! Long wave was no good, I got nothing but noise. We'll see how the rust-bucket compares when it's finally up and running.

Whilst I had the brown one out I thought it'd be nice to see it alongside the black one, so quickly cobbled the dial and speaker grille together, shoved it on the chassis and bunged it in the cabinet, even connected up the dial bulb to the bench PSU for effect 🙂

IMG 6838

Regards,

Lloyd.

 

 
Posted : 29/08/2019 3:00 pm
PYE625, Cathovisor, Nuvistor and 6 people reacted
crustytv
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Posted by: @lloyd

Time for the latest on this rather long winded project!

Not at all Lloyd.

The long projects such as this, are always most informative and at the same time entertaining. They show the reality of a sets journey back to health, all the highs N lows along the way often including difficult hurdles to be overcome. Personally I much prefer threads like this than the "Ta-Daaaa", here it is all finished threads.

This set is really coming along very nicely, hardly recognisable from the rusty old wreck you introduced us to back in May. 

p.s.

How about when its finished, a video to upload to the Vrat youtube channel? A tour of the set working and tuning in some stations. It would be the first Radio on the channel. ? 

CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
Crustys Youtube Channel: My stuff
Crusty's 70s Lounge: Take a peek

 
Posted : 29/08/2019 3:20 pm
Lloyd
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Cheers for the encouragement Chris 🙂

I sometimes wonder why on earth I’m even attempting this project, but then looking back at that photo of the set before I’d even removed the chassis for the first time, and seeing what a mess it was makes it all then seem worthwhile! 

As to a video, back before I went to collect it I was going to film it all from the beginning, I changed my mind when I saw just how bad it really was! Now it’s getting somewhere I might make a start on a little film 🙂 

Regards,

 Lloyd 

 
Posted : 29/08/2019 6:55 pm
Cathovisor
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Posted by: @lloyd

Last time I mentioned the transformer on the other chassis was O/C, well, it turns out it isn't! It also turns out that it's not from an A22 either... I could have used it, but decided against it as it doesn't have the winding for the AZ31 rectifier, which is a directly heated type, it also doesn't have the extra tapping for the dial bulb, so all the valve heaters are wired together on a single 6.3V winding, not sure that would work without changing the rectifier to an indirectly heated 6.3V type, which I don't want to do. Strangely it does look sort of 'Ekco', it even has the mains voltage selector panel that Ekco used, but it's upside-down when on the A22 chassis! Shame, because it fits the hole perfectly!

One (almost) contemporary Ekco I know of that uses that arrangement - of everything on a single 6.3V winding - is the A33 Radiotime. 3-valve short superhet (ECH35, EF39, EBL21) and an EZ35 rectifier.

 
Posted : 29/08/2019 8:30 pm
Lloyd
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Ah, I was wondering what other sets used similar parts, well if I ever get hold of an A33 with a duff transformer, I know I have a good one in stock! I will probably restore the 'parts chassis at some point, so will keep the transformer on it, and rework the rectifier circuit to match the A33. I was actually eyeing up my A23 up on the shelf the other day, wondering if it used the same output transformer as the A22, gave myself a slap on the wrist and said 'No! your not pillaging a perfectly good set for parts!! Leave it alone!' There's also a bashed up AC97 hiding in a corner, which does have an output transformer which is at least the same size as the one from the A22, but I'd like to restore that set someday, it's probably an easier restore than this too, since it's mostly complete, and not got any rust to worry about, but it is missing the dial escutcheon, dial, knobs and back. So many sets to restore! I even bought a Ferranti 'jelly mould' a couple of weeks ago!

Yesterday I finally completed the wiring of the main chassis, now just got the coil pack to re-wire, and the aerial/speaker socket panel. The output transformer is also still in bits pending rebuilding after rust removal and possibly a splash of paint, not too bothered about that transformer, as I'll hopefully replace it with the correct Ekco part someday.

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Might actually be getting some power into this thing soon!

Regards,

Lloyd.

 
Posted : 01/09/2019 11:14 am
Cathovisor
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Posted by: @lloyd

So many sets to restore! I even bought a Ferranti 'jelly mould' a couple of weeks ago!

I have long passed SABLE on sets. Getting rid of duplicates is easy - it's finding the buyers that is difficult - but it's choosing what has to go after that which will be the difficult part for me. Some sets are absolutely sacrosanct - my Murphy TA160, my family's radios/radiograms, my Murphy A40C - but then it gets increasingly grey.

 
Posted : 01/09/2019 11:31 am
Lloyd
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IT’S ALIVE ? more to to follow soon!

 
Posted : 01/09/2019 7:06 pm
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Lloyd
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Sorry it's taken so long to get back to this! I was having way too much fun..

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So last Sunday I'd finally finished all the wiring, there were still components missing, so these were tacked in, and the output transformer was knocked back together after a quick de-rusting, I pinched a speaker from a poor unsuspecting Bush DAC90A and fitted it to the chassis. A full set of valves were fitted, the EBL31 is the one that came with the set originally, I've got a new top cap from a dead valve and glued it on with some Devcon 5 minute epoxy, couldn't find any Araldite in the shops! The first power up was done with the Variac, and I also filmed it too, that will come later! I wound it up and nothing exploded, dial lamp was glowing, at 100V input there was 140V HT, no sound of any signals at this point, but there was a loud scratchy crackle when the tuning was adjusted, back to the problem of the vanes shorting on the tuning cap, touching the top cap of the EBL31 produced a very nice healthy amplifier buzz, so the output stage was definitely working!

I sorted the shorting vanes, there is a tiny bit of adjustment on the tuning gang, wound up the voltage and gave it a  quick alignment, I was then receiving lots of squealing and wailing noises! Not what I'd hoped for, but better than nowt! After much head scratching, and twiddling the alignment, I did what I should have done in the first place, check connections to components for mistakes, sure enough, there was one! C4 had been connected to the wrong tag at the bottom end of the tag strip, once that was corrected, there were proper signals coming through! I managed to receive Absolute radio very quietly, and this was with the alignment still off!

IMG 6872

I spent most of last week tweaking the alignment as best I could, I had 3 different signal generators and the RS frequency counter, and was really struggling with the SW alignment, I just couldn't get the 18.74Mhz in the middle of the 16M band, it was miles off, it just felt like it needed the trimmer to tighten just a little bit more, at which point the screw snapped on the trimmer! Kind of lucky it did in a way, as it revealed 2 faults I hadn't seen earlier, which may have contributed to the difficulty in aligning it, C9 and C13 (on Trader sheet) were detached at one end, looked like the leads had just snapped right close to their bodies.

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With the caps re-connected, and a new bit of 6BA threaded rod and a nut on the trimmer, we were back in business! I managed to get the alignment done, and I can now receive a good number of stations across all 3 bands, although SW seems not to get much, maybe about 2 stations, I could probably check it against the other A22. I'm sure I heard RTE 1 on LW, which I've never really heard before, most of the stations on MW are very loud and clear. I must say I'm impressed that this old heap of rust and mould is working at all! I've sealed the trimmers with a blob of red paint on the ends of the screws.

There are still a good few things to finish off the chassis, the smoothing cap needs something doing with it, it's heavily corroded, and the writing has long since faded, the one on the spare chassis isn't as bad, so I might see if it's serviceable and fit that, if that's no good, I'll have a go at tarting up the original and re-stuffing it, since it's electrically knackered too, it gets very hot very quickly! The new yellow caps could do with something to make them look like waxy caps, I'll have a go at printing off some  labels to wrap round them, then cover them in wax. The resistors could do with changing too, a lot of them have lost their colours, and most of them have changed value too, some are still spot on value, so will be kept. My new resistors look a bit small compared to the old ones! I did try re-stuffing a resistor, didn't work very well, although the new ones will fit inside the old ones, drilling out the contents of the old ones mostly results in them breaking apart. I also need to clean up the bracket for the output transformer, give it a coat of paint. I have a replacement speaker, which looks similar to the one that would have been fitted originally, just need to strip the paint off it's frame, as it's peeling anyway. It's an 'Elac' speaker, looks like mid to late 30's construction, sounds ok, but not as loud as the Celestion from the DAC90A. Need to get a nice mains lead for the set too, since I'm using a short bit of crappy 2 core white PVC for testing.

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That's quite a long post! I'll cut it there, next up a bit of cabinet work...

Regards,

Lloyd.

 
Posted : 08/09/2019 8:58 am
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Lloyd
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On to the cabinet,

Yesterday, I had the chassis playing merrily on the bench, flicking between Absolute radio, and my signal generator with Spotify playing into it's external AF input, and whilst that was going on I had a look at the cabinet. I'd already tried to repair the crack with super-glue, but when the strap I'd lashed round it to keep pressure on the crack was released, the crack popped again! too much stress on the cabinet, as it's warped a bit from bad storage. 

So I put the strap back on, and re-glued it again, this time I left the strap in place, and on the inside of the cabinet I used the Dremel with a cutting disc to make some deep slots in the Bakelite, then I cut some steel pins (actually a bent nail, and a big paperclip!) to fit the slots, glued those into the slots, then stuck some fibreglass matting over the lot and soaked it in glue. The result is a nice solid repair, that should stay put this time, it's survived me giving the rest of the cabinet a polish!

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There was a deep scratch right on the top of the cabinet, which was rather ugly, polish was never going to hide it, so I filled it. For this I first prepared the scratch by scrubbing it out with IPA, just to get as much crud out as possible, especially anything white! Once dry, I dribbled some superglue into the scratch, slightly more than is needed to fill it. When it's hardened completely, I masked off around it with a bit of insulating tape, then sanded it back with P400, just until it's nearly flush with the Bakelite (I actually got a bit carried away and went too far) then remove the masking and sand it with P1200. Once the surface is nice and uniform, I polished it with Paste polishing No.5, this brought back a shiny surface.

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Because the Bakelite is rough from poor storage, it's taken on a lumpy dull surface, so the scratch is still visible, it's actually blacker than the Bakelite now! If this was good condition Bakelite this repair would be practically invisible.

I've reduced the lumpy texture of the Bakelite by giving it a quick sanding with P1200, and polishing with No.5, then to really give it a shine, and darken it a bit, I've given it a coat of Briwax, Antique pine colour, just because it was the darkest colour wax I have. I did try black shoe polish, but to be honest, although it was shiny, all the black pigment stayed on the cloth, and the cabinet didn't look any darker! The Briwax actually made it look darker than the black shoe polish, which was disappointing.

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Now I've just got to do the front, and fill that damned hole!

Regards,

Lloyd.

Just a quick note regarding Bakelite and sanding, There are rumours that many things were used as filler for making Bakelite, one filler that has been mentioned before is Asbestos, there is no way of knowing if it was used in a particular piece of Bakelite, not without getting it tested. Whilst working on this cabinet I have a dust-mask on, and any dust created is being removed with a vacuum cleaner if there is lots of it, such as when using the Dremel to cut the slots, and a damp cloth to wipe down after sanding. Best option is to not attempt it at all, unless your a complete nutter like me...

 
Posted : 08/09/2019 9:33 am
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Lloyd
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Found another boo-boo... Brought the other A22 down to see how the alignment was compared to the rust-bucket, turns out it's not so bad! If my equipment is correct, then the brown A22 is a little off tune. Things got interesting when I checked LW, RTE1 was in a totally different location on the dial! On the brown one it was just past the Oslo marker, on the black one it was nearer Motala! I'd had trouble getting LW aligned, but thought I'd nailed it, clearly I hadn't, must have been tuned to an image of the signal generator? I'm no expert at aligning radio's, actually complete novice is more like it, other sets I've done in the past were a bit rubbish after I'd tried aligning them! So I had another go at alignment, just LW, as SW and MW were pretty much spot on, no matter what I did I couldn't get the 300kHz anywhere near the 1000 metre mark, closest was probably near 1200 with the trimmer fully tightened, then I spotted it, possibly the most ridiculous cock-up I've made in a while! When I found the 2 caps disconnected at one end, I'd assumed that they had both come adrift from the same point, which happened to be a chassis connection point, why I didn't notice that the other end of C13 was also connected to chassis is beyond me! So basically, C13 wasn't in circuit at all, being earthed at both ends.. So after calling myself a prat, amongst other things, I re-jigged the connections to where they should be, C13 should connect to C34! Now there's enough play in C34 to tune the LW band correctly! Now I'm off to put my pointy hat with a big D on it on, and go sit in the corner and face the wall...

Regards,

Lloyd

 
Posted : 08/09/2019 6:44 pm
Nuvistor
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Welcome to the club Lloyd, most of us are members, at least you found the problem and fixed it. ? 

Frank

 
Posted : 08/09/2019 7:12 pm
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PYE625
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Well Lloyd.... You have simply got to pat yourself on the back because this work you are doing is a true restoration through and through. It is a pleasure to follow and it clearly demonstrates the passion you have for the hobby. ? ? 

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 08/09/2019 7:32 pm
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Lloyd
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I'm taking way too long to update this recently! Probably because nothing much has changed...

So what has happened? Well, I've replaced the smoother, and the cathode bypass cap, when it's written like that it really doesn't sound like much! So a few details, the cathode bypass cap, C33 25uF, is mounted right next to the output valve, and quite visible when the back is off the radio, it's in it's own little mounting clamp like the smoother, the clamp luckily cleaned up nicely in rust remover, but the original cap was pretty manky and had to be replaced. Unfortunately, the one on the spare chassis, like most things on it, had been mouse chewed, so re-stuffing it was a no go. I opted for a new 22uF cap, a 450V rated one (probably overkill, since the old one was only 25V!) mainly just because it was similar in size to the old one, to make it look similar to the original part I wrapped it in a bit of plastic to slightly increase it's diameter, then covered it in black heatshrink tubing, and filled the end with a bit of black Milliput, which looks just like the black wax filling on the original! I left the under chassis side with just the heatshrink folding over it, just to leave the vent clear, should it ever decide to pop, and it's hidden under wiring anyway.

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The main smoother was a bit of a dilemma, the original one not only looked manky, it also didn't work, just gets hot when anything above 150V got near it, I tried reforming it, but it was having none of it. Spare chassis to the rescue again! The smoother on the spare chassis was in better condition, only a little corrosion, and it still had it's printing on it. It was slightly different in that it was a 3 terminal can, whereas the original was only 2 terminal, using the can as negative, not a problem, as the A22 chassis has a convenient connection point right next to the smoother hole. Before fitting I wanted to be sure it was electrically OK, sticking it on the cap meter showed it to be miles off value, which was worrying. I built up a little reformer, well actually a monstrosity of a lash up on a bread board, heatsink, and a mains transformer, all wired up as an inverter which could be powered from either the bench PSU, or my solar panels! It was quite capable of generating 500V DC with a good capacitor connected, and as I also proved, it could power the radio very well too! Sadly, I didn't get a photo of it, but if I get the video finished at the end of this project, it'll be in that. I had the smoother connected up over the last couple of weeks, giving it some juice whenever I was in the workshop, there was no way I was leaving that lash up powered whilst I wasn't there! Very slowly I got the cap up to over 400V and around 3.5mA on the 16uF section, and around 1.2mA on the 8uF, the can stayed cold too. The radio only gets up to just over 200V HT, so I decided the cap would be OK, and fitted it. The radio powered up without any trouble, cap stayed cold and the radio played nice and loud without any hum.

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Another thing I'd like to do is to make the new yellow capacitors look a little more 'vintage', since they do stand out a fair bit! This radio arrived with no original waxies to re-stuff, I could use some that I've taken from other sets, but I've decided I want to make new ones, some I can just call up on the PC, print them onto coloured card, wrap them round the new caps and dip them in wax. On the spare chassis there are some waxies, they are a bit battered and some have teeth-marks, but they look like they could yield some useful artwork! I have removed a couple and gutted them, by far the best one was a Hunts 0.1uF, it's a nice little tube with metal end caps, excellent for re-stuffing! But I sacrificed it instead for the scanner, cutting the tube and trying to flatten it so I could get a good scan. Unfortunately whilst flattening it, the card wrinkled and made it look a bit naff, but I got a scan, which hopefully would print off the correct size. The most difficult part is trying to clean up the scan so I have just a plain white background with just the black lettering on it, I only have Paint and Photoshop, and so far have come up with nothing good from either! The old waxy wasn't sacrificed completely, I have since rolled it back into a tube, put some tape round it and fitted a new 0.1uF 630V cap in it and re-covered it in wax, it looks OK! I might use it on the spare chassis when I rebuild it.

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As for cabinet work, nothing else has changed with that, I was going to make a mould of the knobs on the brown one, but discovered that my silicone moulding stuff has passed it's use by date! The catalyst part has separated to clear liquid with all the red bit sunk to the bottom, and the actual white silicone stuff has also gone very gloopy making it extremely difficult to get it out of the bottle, I did get some out and mixed it up just to see if it still worked, and it did! Took it 4 days to set though, so I think I'll have to buy some more. It did last me 10 years! I couldn't believe it was that old, but looking through my emails of stuff I bought off eBay, it was dated 2009! And the same company is still making it, Polycraft, and they do all kinds of different stuff now too. All the moulds I've ever made with it are still in good order, so I could cast new knobs any time.

Regard,

Lloyd

 
Posted : 22/09/2019 5:40 pm
Red_to_Black, PYE625, Red_to_Black and 3 people reacted
Lloyd
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Time for the weekly progress report!

the replacement smoother is holding up well, I've had the radio playing quite a bit this week, probably the most I've ever listened to the radio in a long time, starting to see why I don't bother now, I hate adverts with a passion! Plus the generally rubbish music selection makes listening an unpleasant experience, I think it's time to build a pantry transmitter...

In the last update I was pulling apart a waxy cap to try and make some reproduction ones by scanning the old cases, well that didn't work out so well from the first try, as the card wrinkled when flattened, and of course the wrinkles came out in the scans. Then I came up with the crazy idea of trying to roll a complete capacitor down the scanner as the scanning bit (not sure what you call it, the bit that lights up?!?) wizzed along, as you can imagine, trying to keep up with it wasn't going so well! Got some rather entertaining scans out of it though, might be able to sell them as modern art if nothing else! What it needed was something to keep the capacitor rolling in time with the light up thing in the scanner, I could see that there was metalwork on the scanning thing, so I put a strong magnet on the glass and set it scanning, the magnet followed nice and smoothly, so I ended up with 2 large magnets and a steel ruler, with the capacitor resting on the ruler, the scanner tilted at an angle so the capacitor would roll nicely, then set it to scan and after some adjustments I finally got a good scan of the capacitor! And the scanner didn't break either, although it did make some unpleasant noises. I didn't photograph any of these antics, unfortunately! I could do later though.

After a bit of faffing around with Photoshop, and Paint, I had a cleaned up image of a Hunts capacitor, which I then duplicated many times to fill an A4 sheet of paper, then saved it as a PDF. It's almost black text on an almost white background, which can be printed on coloured card. I printed it out on yellow card, light brown card would be better, like the colour of brown envelopes, as this would be closer to the original.

IMG 6919

To make it more brown, I gave it a rub with 'antique pine' Briwax. I cut out one of the new labels, rolled it into a tube the same diameter as the original capacitor, put in a new capacitor with some paper rolled round it to fill the tube, then used 5 minute epoxy to fill the ends.

IMG 6921
IMG 6920

Once set, I melted some wax, (salvaged from a PP9 battery!) and covered it, trying to get an even coat is rather difficult! I also re-stuffed the original cap, so both can be seen together. I've not fitted any to the radio yet though!

IMG 6922

Another job that needed doing was making the spacer that goes between the dial/ speaker cloth carrier metalwork, and the dial cursor, as this was missing from this set. I had taken measurements from the one in my other A22, and made a very comprehensive technical drawing;

IMG 6923

Ok, a scribble on a bit of dirty paper! I ordered a small length of 1/2" aluminium bar from eBay, which comes in at 12.7mm, perfect size! and yesterday I cleared the bench and gave it a clean, it needed it, it was disgusting!

IMG 6929

I dug the lathe out of the cupboard and set it up on the bench and made up 4 new spacers, 2 of which I made too small, they were just under the 6.45mm width that was needed, but they could still be used, the other 2 were spot on, so that's one for the A22 that is the subject of this thread, and one for the spare chassis, when I get round to restoring it. All that's left to do to them now is drill and tap the 6BA hole for the screw.

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IMG 6931

 

Quite pleased with the result, but I'm sure a proper engineer could have made them up a lot quicker than me, and got all of them the correct size! I must invest in a proper parting-off tool for the lathe, rather than using a hacksaw... One thing I haven't worked out how to replicate yet is the domed brass washer that was between the dial cursor and the spacer, unless I get some flat washers and just bat them one with the ball end of the hammer! 

That's it for this week, hopefully I've been paid so I can order up the new dial that I've been wanting, as well as some silicone moulding gunk, and resin to make the new knobs and fill that hole. Back on shifts at work next week again (yuck...) so progress will probably grind to a halt 🙁

Regards,

Lloyd

 
Posted : 29/09/2019 12:20 pm
PYE625, PYE625 and PYE625 reacted
PYE625
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Posted by: @lloyd

probably the most I've ever listened to the radio in a long time, starting to see why I don't bother now, I hate adverts with a passion! Plus the generally rubbish music selection makes listening an unpleasant experience, I think it's time to build a pantry transmitter...

I like Gardner's Question Time and the shipping forcast on The Light Program (R4 LW in modern jargon), but that's about it. Oh what happened to "Melody Hour" ?

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 29/09/2019 3:25 pm
Cathovisor
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No Andrew, Radio 4 is the old Home Service.

And we have 'programmes' here in the UK 😉

 
Posted : 29/09/2019 5:36 pm
PYE625
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Now, I was going to say "Home", but looked at a couple of dials and they said "Light" so I was confused. It was enough to make me forget the correct spelling of programme. ? 

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 29/09/2019 6:04 pm
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