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 Post subject: Radiola Brunswick AR-813 / BR60 Combo Batteries
PostPosted: Nov Sat 08, 2014 7:06 am 
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Joined: Jul Mon 07, 2014 5:04 am
Posts: 17
This is my first battery set, second resoration. I have diagrams for the AR-812 set but my question has to do more with batteries. The back of the set has these 4 spaces, I am having trouble visualizing what batteries go where, I have seen a black and white photo of a stand alone AR-813 that showed the A batteries stacked up in pairs, but I do not see the same cubbybspace in this unit. The 812 appears to have two sets of batteries, one on each side that apear to balance them out. That being said, I cant' figure out how 4 B cells should stack in there, or should it be a 90V cell with a 45V tap?

To further complicate matters, my references for battery dimensions are all over the place. Round A cells seem to be relatively standard (built with mailing tubes), but everything else varies.

My current plan is to just build up a single 90V/45V battery with #10 9V batteries, but I also thought I may go the #60 count AA route, with the understanding that it is supposed to give better mah rating. Either way, I would scsle it to sit in the bottom of the big 8.5 x 13.75 space on the right.

The A battery I think would stack up as a pair of three 1.5V (each with three D or C cells in parallel) in the middle section on the left that measures about 5.5 square by 6.25 deep to make a 4.5V filament source.

The C battery will go in the left top at 4.5V, maybe some C or AA cells in series.

it looked like maybe on the left the middle and bottom sections would stack square cells two high as well. Not sure if they made something that fits like that.

Any opinions, advice or photos of what this originally looked like would be helpful and appreciated.


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 Post subject: Re: Radiola Brunswick AR-813 / BR60 Combo Batteries
PostPosted: Dec Fri 14, 2018 10:56 pm 
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Joined: Dec Tue 11, 2018 10:49 pm
Posts: 5
I am not able to upload the photo because it says the file is too big. But ours has a battery that says it was installed on January 5, 1931. It is song bird brand. Number 600, 4 1/2 V, C battery.


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 Post subject: Re: Radiola Brunswick AR-813 / BR60 Combo Batteries
PostPosted: Dec Sat 15, 2018 4:44 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 14272
Location: S. Dartmouth MA 02748-1225 USA
There were light, medium and heavy duty "B" batteries. The size varied between the "strengths" as well as how the cells were stacked.

IMHO build 45 volt packs. That is 30 cells in a 5 x 6 array, homemade cardboard egg crate, use corrugated cardboard for buffer/filler and dense "Bristol board for a container. Alternately, try a full service art store that has unfinished thin wall wooden boxes that will accept 30 cells with minimum loss to cardboard filler.

I have used child's metal lunch boxes with great success. These are now made China with no designs available from Amazon. Use fiber washers with binding posts to get electrical connections through the metal. Think through the jumpers and the -, 22-1/2 and 45 volt connections will be very short. Use a high wattage soldering iron with a LOT of copper in the bolt. A puny 40 watt electronic iron will overheat the seals in the cell and cause a dry-out failure. Soldering the jumper should take no more than 5-8 seconds.

Image

Image

These three batteries have "F" cells, then used in "Heavy-Duty" "B" batteries. They were recovered from a distributor that ended sale of Zenith T.O. battery packs. They are taller than "D" cells so a lunch box could have less depth for "D" cells or fill out with corrugated cardboard. Yes, these are dead after 40 years...

Plain Metal Snack Box

I have also used Rubbermaid food storage containers and also rebuilt OEM 20's batteries.

A word from a 40 year battery builder. Get the specs for the cells to be used, look at the normal MA draw and use a power resistor to create that draw. Place a voltmeter across this resistor and test the strength of each cell in terms of volts vs the current draw. This test will weed out any weak cells.

If at anytime a cell or a group of cells accidentally gets shorted even for a moment, do not build with these cells. A short causes a dramatically shortened life and almost guarantees perforation of a seal or zinc case leading to an electrolyte leak that will shat other cells... Save the shorted cells for a flashlight or other 'mundane" device...

I have not experiment with replacement of #6 cells, then, they were still available. I have done a bit of research and found thin wall plastic tubing and plastic end caps that will work only needing a filler for the top. Replication is not exact but tube will accept self stick laser printed color graphics and the plastic cap will allow a renewal of the cells, plastic will resist a leaker...

You will need to check the catacomb for failures, use the RCA continuity check with an analog meter, a digital meter may give strange readings because of coil inductance.

RCA Service Notes 1923 to 1928

May, be able to provide a catacomb service replacement with a dud trade...
I have a catacomb test frames for the 6-tube V-cat, 6-tube UX cat and the 8-tube cat.

You must also check the reproducer for an open coil or frozen threads. The internal rubber gaskets will be hard and will have to be replaced or the metal diaphragm will buzz on loud notes. If the pot metal bottom is frozen this can be a problem. It may require a search for an alternate driver with a threaded adapter. Suggestion is a Utah, Baldwin, Saal and others with a bi-polar driver motor and a mica diaphragm. That would give a significant improvement in fidelity. Weak driver magnets will cause a weak output. Failing that a high compliance modern ceramic magnet mini speaker with an output transformer will perform nicely.

I also have a BMP file for the logging charts that are placed behind the tuning dials. This is a single tuned radio with a low IF frequency and will have two-spot tuning, The paper dials enable logging the preferred spot usually with less interference.

There is an adapter UR-556 for the last audio to use a 120 output tube, same filament but and additional battery for a total of 13 volts and an additional "C" battery of 22-1/2 volts. Doubles the audio output to 3/4 watt.

That may explain the extra room in the battery compartment for an additional 45 volts and the additional "C"...

An outdoor antenna/earth ground can be coupled magnetically to the swing out loop. A direct connection to the loop will shift the tuning and may inhibit the total tuning range. A range from about 500 to 1350khz is normal for this radio...

Oh, and this: Tubes

YMMV

Chas

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Smith's Ale Gives Strength, Smith Bros. Brewers, New Bedford MA


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 Post subject: Re: Radiola Brunswick AR-813 / BR60 Combo Batteries
PostPosted: Apr Sat 20, 2019 4:44 pm 
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Joined: Apr Sat 20, 2019 4:41 pm
Posts: 1
I have AR-813 and I am considering building batteries as well. What did you finally decide to do? Can you share photos of what you made?


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 Post subject: Re: Radiola Brunswick AR-813 / BR60 Combo Batteries
PostPosted: Jun Fri 21, 2019 1:18 am 
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Joined: Jul Mon 07, 2014 5:04 am
Posts: 17
I have been away from the forum for a long time but I will see if I can get a photo or two of what I did. It was a while ago, but I recall I simply soldered a bunch of 9v battery connectors together and used some 1.5v battery holders wired up for the other voltages, then I just piled them all into the cabinet. Sort of a point-to-point wired battery system as I recall, ugly but hidden from view, not one person has asked to see them and I actually just turned it on a couple days ago, and it still works, I have not opened the back in a while but the batteries have been in there for nearly 5 years now.


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