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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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2nd Dec 2016, 1:22 am | #1 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
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BLR121 battery for AVO (Quick solution)
This is a rapid solution to the long running problem of 15 volt batteries for AVOs.
Once you get good it becomes a 10 minute job I have discovered that a 15mm water pipe stop end is the correct length to make up 5 CR2032s to the length of the original BLR121. It was a very rapid job with a bit of insulation tape and even the label off of an old one. I did fiddle about with slices of pipe before coming up with the idea of the stop end without the nut or olive. As the cells are sold as calculator batteries this had to be a calculated solution. If anyone has an end feed stop end it would be useful to see if those also fit. The Maxell branded cells have a textured negative terminal that grips the battery terminal. The stop end may need to be center punched for the terminal to make good mechanical contact. Mine has a brand name stamped on it so it did not need to by center punched. |
2nd Dec 2016, 12:42 pm | #2 |
Nonode
Join Date: Mar 2013
Location: Leicester, UK
Posts: 2,505
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Re: BLR121 battery for AVO (Quick solution)
I was able to do something similar with a MkIII I had a while back, except I used CR2032's from a pound shop and a thick nut in my bits and bobs tin for the spacer. More recently I had a MkII with a dead BLR151 clone in it. The two halves of the battery casing came apart easily by cutting the labels on either side. It was then a matter of discarding the old array of button cells, cleaning up and replacing the 10 button cells - again obtained from the pound shop - putting the two halves of the case together and wrapping some tape around them.
I actually purchased a BLR154 for the MkVI, although perhaps even this could have been constructed in a similar manner from a series of button cells. |
2nd Dec 2016, 1:00 pm | #3 |
Banned
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
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Re: BLR121 battery for AVO (Quick solution)
I have found BLR154 and BLR 121 are available from many sources.
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2nd Dec 2016, 4:18 pm | #4 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
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Re: BLR121 battery for AVO (Quick solution)
The BLR121 has a habit of being expensive enough that it is worth the effort making up replacements.
The BLR154 is a little bit less expensive but may not last as long due to it being only 12 volts. |
2nd Dec 2016, 4:37 pm | #5 |
Octode
Join Date: Nov 2005
Location: Surrey, UK.
Posts: 1,869
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Re: BLR121 battery for AVO (Quick solution)
Unless the stack of button cells is insulated, putting them in a metal sleeve can short out some cells. Plastic water pipe is a better bet.
Leon. |
2nd Dec 2016, 4:54 pm | #6 |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
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Re: BLR121 battery for AVO (Quick solution)
Or a piece of rubber hose. https://www.vintage-radio.net/forum/...1&postcount=10
__________________
Regds, Russell W. B. G4YLI. |
2nd Dec 2016, 5:09 pm | #7 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
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Re: BLR121 battery for AVO (Quick solution)
A metal tube will short all the positive terminals together killing all but the end cell. They would have to be sleeved with an insulated material such as heat shrink if they are to be fitted in a metal sleeve.
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2nd Dec 2016, 8:21 pm | #8 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,316
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Re: BLR121 battery for AVO (Quick solution)
A few years ago I made up a 6V battery for my pocket Rollei camera from 4 button cells, wrapping round a couple of turns of non-oozing Sellotape magic mending tape to provide insulation. 4 cells were the same length as the original battery, so no packing was needed.
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3rd Dec 2016, 4:56 pm | #9 |
Nonode
Join Date: Mar 2013
Location: Leicester, UK
Posts: 2,505
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Re: BLR121 battery for AVO (Quick solution)
Agreed, but I believe that the op was using the 15mm of pipe as a spacer rather than a sleeve. The clone BLR151 casing that I was able to split apart was plastic so there was no risk of any cells shorting.
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3rd Dec 2016, 5:53 pm | #10 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
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Re: BLR121 battery for AVO (Quick solution)
The original battery I made was indeed made with a 15mm stop end as a spacer.
I did it so that the brand name stamped on the face of the stopper allowed the spike style terminal to locate in the lettering. The five cells were just simply stacked and taped and then taped to the stop end so making the length up. The cells are large enough that they will not slip into the stop end but large enough to make good contact with the end of the threaded part of the stop end. |