|
Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
|
Thread Tools |
25th Jul 2007, 4:33 pm | #1 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
|
Replica grid bias batteries
Hello fellow avocados
Continuing my request on https://www.vintage-radio.net/forum/...ad.php?t=18498 I have managed to complete one of these. Thanks to Michael Cummings for the pictures of his originals and Radio Dave for doing the graphics for me. The batteries have wander sockets and are tapped every 1.5 volts. The top is filled with pitch with the sockets showing flush. Here’s how I did it – usual procedure for using 250gsm white card and preferably a colour laser printer. Cut and score bends with the back of a knife, and use PVA adhesive to assemble. I dismantled the metal parts of the sockets so the plastic could be shortened; as made, the metal sockets are below the plastic bits, but need to be level with the “pitch”, so the metal needs to show. There was about 4mm to remove on top, so as just to leave a small "flange" showing. After shortening the plastic, I put the sockets back in, and flattened the tags and bent them over, as there is very little room in the finished battery box. The stripboard top needed to be drilled for the sockets, the end one being spaced closer. Because I was going to fill it with liquid resin, I put a strip of Sellotape across the top side to stop the resin leaking out into the holes. Three more bits of stripboard soldered to the top, and six AA cell holders and a bit of wiring and spotfacing completed the electrics. All that remained was to make a mould from card to fill the top with resin. I lined it with Sellotape to form a “release agent”. The resin was mixed with black poster colour to make the finished article look like pitch, and after removing the mould card, it all popped into the case. It was a few mm proud, but I can live with that; maybe AAAs would be better. As the finished article will be clamped on either side of the front, the slight bowing of the box will not matter. I’ll start a thread when I have made the alloy clamps and another battery; this will complete the Taylor 44 transistor tester. It only uses 2 cells on one battery, so a bit of cheating is in order. It's OK, Bill (batterymaker1) - we'll not give up the day job! Yet.
__________________
Mike. |
25th Jul 2007, 5:32 pm | #2 |
Heptode
Join Date: Apr 2006
Location: Indianapolis, Indiana, USA.
Posts: 674
|
Re: Replica grid bias batteries
Both of you oughta be doing them as a side business--very professional fit and finish in your final product.
__________________
Just playing with high voltage.... |
25th Jul 2007, 6:38 pm | #3 |
Heptode
Join Date: Aug 2006
Location: Sheffield, South Yorkshire, UK
Posts: 990
|
Re: Replica grid bias batteries
Hi Mike
I must agree with Bill, what a really professional job! Top marks for effort and attention to detail! |
25th Jul 2007, 9:43 pm | #4 |
Nonode
Join Date: Jun 2004
Location: Norwich, Norfolk, UK.
Posts: 2,543
|
Re: Replica grid bias batteries
Hi Mike,
They look absolutely brilliant, well done . One day I'll get around to making mine... Regards David |
28th Jul 2007, 11:57 am | #5 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
|
Re: Replica grid bias batteries
Thank you all for your encouragement.
Now, in true reverse Blue Peter fashion, here is one I did later - the "cheat 9 volt battery" that is actually only a 3 volt battery. I shall be posting a thread shortly in Equipment to show you what it is used for.
__________________
Mike. |
28th Jul 2007, 7:10 pm | #6 |
Octode
Join Date: Jun 2004
Location: Hampton Vale, Peterborough, UK.
Posts: 1,698
|
Re: Replica grid bias batteries
Great work, Mike - as always. Seriously, is there anything you can't turn your hand to? I guess that praise from Bill (batterymaker) is praise indeed.
Avocados, you say. Peers, not pears, is what we are! -Tony |
28th Jul 2007, 7:49 pm | #7 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
|
Re: Replica grid bias batteries
The list would be too long for the bandwidth, Tony!
Wallpapering and gardening are probably quite high on the list. Oh yes, trying to understand rules about ball-y things as well. The rest of the stuff I view as necessity; I needed a couple of GB batteries, and thought it would be good to make them look original, so I went for it.
__________________
Mike. |
28th Jul 2007, 7:55 pm | #8 |
Octode
Join Date: Jun 2004
Location: Hampton Vale, Peterborough, UK.
Posts: 1,698
|
Re: Replica grid bias batteries
Ball-y things football, for example? Its all b... well, you know what I mean. I have a friend who constantly introduces me to others as 'his mate who can't stand sport'. I have tried, many many times without success, to tell him that football is not the only sport and that, on occasion, I can and do enjoy watching motor sport (bikes and cars), athletics, marathons, even tennis, but he has a mental block. At least, that's what I think it is!
Gardening you can keep. Worms, mud, flies and boredom. We paint our walls these days. Keep making the batteries! -Tony |
29th Jul 2007, 11:47 pm | #9 |
Heptode
Join Date: Feb 2006
Location: Roscommon, Ireland
Posts: 732
|
Re: Replica grid bias batteries
Excellent job Mike. They look exactly like the originals.
The pitch like resin really finishes them off. Regards Frank |