[ARC5] Battery Report

[Bill Cromwell]

Hi Rich,

I started using the batteries for B+ to avoid power line crud conducted 
into the radio from that source. Digital (switched mode) power supplies 
are usually pretty noisy too. It worked and the noise pollution into the 
radios was reduced. As a side benefit my radios didn't turn off when the 
electric grid went down:) I use 7.5 A-H sealed lead-acid batteries For 
the heater strings. So throw away batteries for B+ that lasts weeks or 
months and bigger ones for the heaters that can be recharged over and 
over - is that redundant?

I settled on 90 volts and the radios draw about 15 mA at 90 volts B+. I 
also tried 45 volts. The radios worked and the radios only drew about 7 
or 8 mA but performance was down enough to notice. I could change those 
screen bias resistors and use just 45 volts but I am reluctant to 
further modify those radios. They haven't been hacked to bits but do 
have some reversible mods that were installed long before I acquired them.

73,

Bill  KU8H

On 2/2/20 4:23 PM, Rich Post wrote:
> I have also found that the cheap old fashioned carbon zinc cells seem to 
> be less prone to leakage than alkaline cells.  Like Wayne, I use the 
> cheap Sunbeam cells from Dollar Tree.  If I am concerned about leakage, 
> I place several soldered together inside a pill bottle and run leads to 
> the outside with wire nuts.  That is especially useful in VOMs where the 
> original "D" cell holder is broken or  damaged by leakage products.  The 
> pill bottle size is chosen to fit the "D" cell space and the wire nuts 
> make it easy to replace the package later.
> 
> For powering a Command set receiver, I have yet to try a simple tripler 
> or quadrupler off the 24 volt transformer used for filaments. Have 
> successfully used such a tripler for 90 volts of B+ to a farm set.  
> Given the relatively limited current draw, a quadrupler might work for a 
> Command receiver.
> 
> Rich KB8TAD
> 
> On Sun, Feb 2, 2020 at 3:39 PM Robert Eleazer <releazer at earthlink.net 
> <mailto:releazer at earthlink.net>> wrote:
> 
>     __
>     It seems to me that the old carbon zinc cells (which I believe the
>     Sunbeam cells from Dollar Tree represent) were less likely to leak
>     than the modern alkalines.  I think they did less damage, tooi. 
>     Remember when Everyready advertised leak proof cells and that they
>     would replace the flashlight if required?  I think they stopped that
>     when the alkalines came out.
>     As for as rechargable cells, the LI-Ion types seem to be far
>     superior to nicads and NIMH when it comes to holding a charge.  I do
>     have a couple of 18657 Li-Ion cells that arrived brand new and dead
>     with no re-charging and a couple more that died after a short
>     service life.
> 
>     Wayne
>     WB5WSV
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-- 
bark less - wag more