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Battery Shock!!

Posted: Sun Feb 26, 2012 10:32 am
by Lenp
I had a friend stop over recently with an old portable tube radio. You old timers will remember, the IU4, IT4, 3V4...
He was interested in getting it operating again just for grins. That quickly got shelved when we looked for the batteries.
The 'B' battery, 67.5V is $60+ and the 7.5V 'A' battery we could not find. No interest in making an AC power supply.
I't a dust-it-off shelf piece again!

This reminded me of time I talked to a tech at a local hospital. They has a bunch of cardiac patient telemetry units that used a very 'special' battery. It looked like and was the same size as a standard 9v battery, but, it was 10.5V. The cost, because it was proprietary, was astronomical. If you used a standard 9 volt, it screamed low battery. He said the hospital bought them because the were the low bid!!

Gee, that's kinda like the printer and ink deals of today.

Len

Re: Battery Shock!!

Posted: Mon Feb 27, 2012 3:44 am
by dacflyer
proprietary items really do suck, and usually for no real good reason.
electronic connector items to name one...

Re: Battery Shock!!

Posted: Tue Feb 28, 2012 4:39 am
by Gorgon
Lenp wrote:I had a friend stop over recently with an old portable tube radio. You old timers will remember, the IU4, IT4, 3V4...
He was interested in getting it operating again just for grins. That quickly got shelved when we looked for the batteries.
The 'B' battery, 67.5V is $60+ and the 7.5V 'A' battery we could not find. No interest in making an AC power supply.
I't a dust-it-off shelf piece again!

Len
Why not try to make a DC-DC converter, or two, from a standard chargable battery. I'm not sure if you could make it for the same space as the old batteries, but the new Litium alternatives take little room.

Just a brainfart :D

TOK ;)

Re: Battery Shock!!

Posted: Tue Feb 28, 2012 6:21 am
by Lenp
Guess I forgot to add that the friend wanted to 'restore' it, not just make it play!
Thanks

Re: Battery Shock!!

Posted: Tue Feb 28, 2012 9:24 am
by dacflyer
anyone remember the battery packs that were used in the old military handy talkies ? i remember them being a multi voltage block battery. wonder if they are still available.. i cannot remember the voltages they had, i think 67V - 6v , and one other..
might have been sort of like a A,B,C battery pack.

Re: Battery Shock!!

Posted: Tue Feb 28, 2012 12:55 pm
by Janitor Tzap
Here is the wikipedia page with most known batteries.
http://en.wikipedia.org/wiki/List_of_battery_sizes

Since the batteries physical size is the problem.
Make up your own 67V battery and 7.5V battery.
Check your local Dollar Store for AG13 1.5V Button Batteries,
Or CR2032 3V Lithium Coin Batteries, and make up the packs yourself.

AG13 1.5V Button Batteries.
American Science & Surplus has cards of 10 Cells for $1.95.
http://www.sciplus.com/category.cfm/sub ... /srch.fp/1
48 X 1.5V = 68V
CR2032 3V LITHIUM Coin BATTERIES.
American Science & Surplus has cards of 20 Cells for $5.95.
http://www.sciplus.com/category.cfm/subsection/13
25 x 3V = 67V

As for restoring the radio.......
See if you can't find the make and model.
Sam's Photofacts has schematic's that go back as far as 1946.
It may be out of print though.
So, you may need to check if you can get a copy from them.
If it is earlier then that.....
Sometimes, but not always the schematic was pasted to the inside the cabinet.

Replacing some of the old capacitors can be a challenge.
I found I could use polyester film type capacitors as replacements.
But to get the capacitance value at, or close too the original capacitor.
I had to wire two or more of them in series, or parallel.
The same for resistors.

Note: Tolerance's weren't as tight as they are now.
Thus, if a resistor's labeled value is 10 ohm, but has a 10% tolerance rating.
The resistor is still considered good if it reads between 9 to 11 ohms.
The same for capacitors.


Signed: Janitor Tzap

Re: Battery Shock!!

Posted: Wed Feb 29, 2012 8:17 am
by VernGraner
Lenp wrote:The 'B' battery, 67.5V is $60+ and the 7.5V 'A' battery we could not find.
Possible solution (depending on the available space) the "B" battery could be made from a relatively inexpensive "Stack" of regular off-the-shelf 9v batteries. seven of them in series would deliver about 63 volts? Connect the batteries in series and tape them into a package. The 7.5v pack could be made from five AA batteries in series. Again, this depends on how much space is available inside the radio. :smile:

Vern

EDIT: five batteries, not seven as first posted. :razz:

Re: Battery Shock!!

Posted: Wed Feb 29, 2012 9:50 am
by Janitor Tzap
VernGraner wrote:
Lenp wrote:The 'B' battery, 67.5V is $60+ and the 7.5V 'A' battery we could not find.
Possible solution (depending on the available space) the "B" battery could be made from a relatively inexpensive "Stack" of regular off-the-shelf 9v batteries. seven of them in series would deliver about 63 volts? Connect the batteries in series and tape them into a package. The 7.5v pack could be made from 7 AA batteries in series. Again, this depends on how much space is available inside the radio. :smile:

Vern
I haven't seen any inexpensive 9V Batteries lately.
But I have been seeing lots of cheap AA & AAA Alkaline Batteries.
I paid $6.00 for a 60 Pack of AAA's.
{That's .10 a cell.}
You just need to figure out how to wire them up in series. :wink:
dacflyer wrote:anyone remember the battery packs that were used in the old military handy talkies ? i remember them being a multi voltage block battery. wonder if they are still available.. i cannot remember the voltages they had, i think 67V - 6v , and one other..
might have been sort of like a A,B,C battery pack.
Here, I found these on Wikipedia.
AN/PRC-6 Walky-Talky
http://en.wikipedia.org/wiki/AN/PRC-6

Plus, the SCR-536 "handy-talkie".
http://en.wikipedia.org/wiki/SCR-536


Signed: Janitor Tzap

Re: Battery Shock!!

Posted: Wed Feb 29, 2012 1:21 pm
by VernGraner
Janitor Tzap wrote:I haven't seen any inexpensive 9V Batteries.
I guess it depends on the definition of inexpensive. :) Many of the home improvement / hardware stores sell house branded "contractor packs" of batteries. (A bit of googling later) found a battery wholesaler:

http://www.batterywholesale.com

That link above is qty 12 of 9v alkalines for about $20.00 :smile:

Vern

Re: Battery Shock!!

Posted: Wed Feb 29, 2012 4:34 pm
by Janitor Tzap
VernGraner wrote:
Janitor Tzap wrote:I haven't seen any inexpensive 9V Batteries.
Janitor Tzap wrote:I really should of added; "Lately". :lol:

I guess it depends on the definition of inexpensive. :) Many of the home improvement / hardware stores sell house branded "contractor packs" of batteries. (A bit of googling later) found a battery wholesaler:

http://www.batterywholesale.com

That link above is qty 12 of 9v alkalines for about $20.00 :smile:

Vern
Not bad, that's $1.67 each.
I've been buying 9V Alkalines from the Thrift, or Dollar Stores for $1.00 each.
This one thrift store that was closing it's location,
was discounting stuff some 75%.
Thus, I got a real good deal on a 12 pack of 9V Alkalines.
Paid only $3.00 for the pack, that's $0.25 each. :grin:


Signed: Janitor Tzap

Re: Battery Shock!!

Posted: Thu Mar 01, 2012 5:20 am
by MrAl
Hi,

That was my first thought too, to make the larger battery out of several small 9v batteries and put them inside a box that is shaped like the old big battery and paint it to look like the real thing. It might not be super cheap but at least it is doable.

I think what Vern meant for the smaller 7.5v battery was "5" batteries in series not "7". I dont know what the current requirement is for that radio however so im not sure what smaller batteries you could get away with like button cells.

Re: Battery Shock!!

Posted: Thu Mar 01, 2012 3:45 pm
by Janitor Tzap
MrAl wrote:Hi,

That was my first thought too, to make the larger battery out of several small 9v batteries and put them inside a box that is shaped like the old big battery and paint it to look like the real thing. It might not be super cheap but at least it is doable.

I think what Vern meant for the smaller 7.5v battery was "5" batteries in series not "7". I don't know what the current requirement is for that radio however so I'm not sure what smaller batteries you could get away with like button cells.
You make a good point MrAl.
Though, I went back and checked the stat's on the AAA, AG13, and the CR2032 batteries.
The AG13 1.5V Button Cell has a 150 - 200 Mah Capacity.
The CR2032 3V Coin Cell has a 190 - 225 Mah Capacity.
The AAA 1.5V Cell is rated 540 - 1200 Mah Capacity.

So, if space isn't that much of an issue.
I'd use the AAA Cells to make up the Battery Packs.
Being that they have more Mah Capacity, and will last longer.


Signed: Janitor Tzap

Re: Battery Shock!!

Posted: Thu Mar 01, 2012 6:53 pm
by Dean Huster
The "B" battery won't draw that much current, so the stack of 9v batteries will last nearly their shelf life. The "A" battery on the other hand powers the tube filaments/heaters and won't last nearly as long. "C" or "AA" would be the cells to put in series there. The normal thing for antique radio restorers is to make an AC mains operated supply for the radio with the proper output connectors so that you don't have to modify the original radio in any way. Also, if you build the line-powered supply to fit the original battery space, it's so much the better. Restorers don't like adding anything modern to restore the radios, finding cotton-covered wire and original-looking line cords or emptying out the innards of the original electrolytic capacitors and inserting modern caps inside them so you can't tell anything was changed.

Re: Battery Shock!!

Posted: Fri Mar 02, 2012 4:07 am
by reloadron
dacflyer wrote:anyone remember the battery packs that were used in the old military handy talkies ? i remember them being a multi voltage block battery. wonder if they are still available.. i cannot remember the voltages they had, i think 67V - 6v , and one other..
might have been sort of like a A,B,C battery pack.
When I was a kid I got my hands on a set of BC 611 handy talkies. They used two batteries, one a 1.5 volt for the filaments and the other was a 103.5 volt battery that internally ran the entire height of the unit and provided the plate voltage. Those batteries were expensive back then when you could find them. :)

I would go with a stack of 9 volt batteries as mentioned.

Ron

Re: Battery Shock!!

Posted: Sun Mar 04, 2012 4:49 am
by jwax
I recently picked up a "battery brick" of 25 9-volt alkaline "Premium" cells made by "Utilitech" of China. $19.95 from Lowe's.
I've not done a lab test on their capacity, but in general use, as expected, they suck.
Maybe run for half the normal alkaline lifetime.
Shoulda known.
:mad: