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Radio Another Bakelite disaster! GEC BC4941

 
Lloyd
(@lloyd)
Noble V-Ratter Registered
Posts: 1544

Yes, I know… Bakelite in the post is a dumb idea… some of us will never learn! But in my defence, these sets are built like a brick you know what, and it takes a hell of a lot of force to do this much damage! But never mind, it’s not cost me anything, other than a bit of time!

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So what to do with it? Well first things first, it’s not as terrible as it first looks! Good points are the chassis and valves are all perfectly OK, the speaker is good, it’s nice and clean with very little corrosion (unlike the other one I have!) and the rear cover survived completely undamaged. The bad bits, the front case is in 3 pieces…. And it’s green Bakelite, which I find the most difficult to repair! And the tuning dial glass is in a million pieces.

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To begin with I thought it’d be good to see how much work the chassis needs, so I borrowed the 6V to 90V inverter that I made from the Bush BP10, got a new battery for it and connected it up. Absolutely nothing happened when trying to power it up! So I connected it up to the bench power supplies instead, so I could see if either HT or LT were drawing current, neither were, so I immediately thought the valves had probably croaked due to being bashed, or someone plugging in a 9V to the filaments (I’ve done that before, when I was little!). Each valve was pulled and checked, and all found to be ok, so it must be something else, the battery wires checked out fine, so I pointed the finger at the switch, I gave it a good blast of Servisol, and then exercised it, which got it drawing current at last! There was a bit of crackling when switching, but not much of anything else. I got the circuit up, and had a look for the audio coupling cap, on this set it’s a wax covered mica thing, and they are normally good, and this one was, no leakage, but there is another audio coupling cap on the volume control, which is a wax covered paper cap, it didn’t seem leaky, but I’ve disconnected it and tacked in something new just to see if it made a difference, it didn’t! After a while the current draw on the HT started to rise, and the 4uf HT cap was heating up, so that too was disconnected and an ill fitting replacement tacked in. I tried using the MiniMod pantry transmitter to get a signal through it, and I could receive that, but it was still quiet. Careful fiddling with the tuning could bring in Absolute radio very quietly too. I had noticed the red sealing paint On the first IF adjuster had crumbled off, but so far I’d managed to resist the temptation to twiddle it! But I gave in and found the adjuster to be quite loose, possibly from being bashed, and giving it a little turn suddenly livened things up a bit, so much in fact that I had to turn the volume down! I set it so that Absolute radio was nice and loud, I will probably do a proper alignment on it later, but as it is, the set is now pulling in stations loud and clear on both bands with just the frame aerial. It is also now running on the 6V inverter, which can be placed neatly inside the set to keep it portable.

So now another dilemma! I have another of these sets, in a rather less than pleasant brown colour, cabinet is mint,  but the chassis is a mess in that one, and it’s speaker is completely rotten, it’s also been in bits in a box since 2017! I’m tempted to take the chassis from the green one and put it in the brown cabinet, but I’d really like to get the green cabinet back together, and keep the good chassis in that. And I still need a new dial, well 2 of them, as the one from the brown one is broken too!! I think I’ll just house the chassis in the brown cabinet for now while I work on repairing the green one.

I’ve tried test fitting the pieces back together, but found it almost impossible to get all the bits back, I think this is going to take some very delicate work with the dremmel to get the bits fitting nicely before I can glue them! I will be using my tried and tested method of good old cyanoacrylate to repair it, but I want to find the low viscosity type again, as it’s great at seeping into the cracks, sadly it’s also good at making a run for it out of the bottle, even with the lid on! I lost a bottle of it when we moved house, as it managed to escape and glue everything in the box it was in to the bottom of the box!

 Regards 

Lloyd 

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Topic starter Posted : 05/02/2022 3:49 pm
Lloyd
(@lloyd)
Noble V-Ratter Registered
Posts: 1544

Managed to dig out the other cabinet yesterday, so spent some time transferring the chassis into it. I couldn’t find the dial glass from the brown one! I’ve put it somewhere safe, and forgotten where that actually is… At least it looks like it will just slide into place with the 2 clamps removed, without having to take the chassis out again.

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Regards 

Lloyd 

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Topic starter Posted : 06/02/2022 1:59 pm
Lloyd
(@lloyd)
Noble V-Ratter Registered
Posts: 1544

Found the dial glass, it was right in front of me the whole damn time, under the workshop PC monitor! It was also damaged, but not as badly as the other one. I also came to the conclusion that Loctite’s ‘super glue for glass’ is a bit rubbish, as I’d stuck this back together with it back in 2017, but found today that it had come apart again, and it looks like the glue had dried out, as I remember it being slightly rubbery after it had set before, but now it’s dry and flaky. I stuck it back together with bog standard superglue this time, it’s not the best example of a dial, and I do intend to have a go at making replacements anyway.

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On the subject of replacement dials, I was looking at companies online that will print your own photos onto glass, they seem mostly to do it onto large pieces for use as splash backs in kitchens, but I wondered if they could do dials! I’ll have to see if it’s possible, and cost effective. Maybe I should get a large batch done and flog the remainders at RetroTechUK!

I’ve been using this radio in the workshop quite a bit and I must say it’s pretty good! Sound quality is as good as similar sized mains sets, maybe not as loud, but still well balanced, with enough bass to make it not sound tinny! Battery life is fairly good too, I’m using a single D cell for the LT, and I’ve not had to change it yet, and it’s quite an old one! Previously I’d said my Bush BP10 was the best sounding battery valve portable, but this one beats it.

 Regards 

Lloyd 

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Topic starter Posted : 18/02/2022 8:51 pm
Boater Sam
(@boater-sam)
Reputable V-Ratter Registered
Posts: 420

I have an artist neighbour who works in minute detail, like inside snuff bottles!

She would be capable of painting tuning dials in reverse if anyone is interested.

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Posted : 19/02/2022 10:47 am