[Thursday] New aquisition

[Arzoo623 WebRight]

Chris, what was the name of the shop? I have the history of a few battery shops on my website? What was his name?

Len

Sent from my iPhone

> On Aug 12, 2019, at 1:36 PM, Chris Prata via Thursday <thursday at newsm.org> wrote:
> 
> That's interesting and as an aside I can share that my grandfather owned a battery shop in the 1920s in Providence. He went into a lot of detail telling me all about it. They had a Model T delivery truck with heavy duty rear springs and would bring the batteries around which were lead acid, to their customers and bring the depleted batteries back.
> 
> They had waffle iron type molds and a gas stove with pots of melted zinc and Lead to make new plates so they could rebuild these batteries.
> 
> If I recall correctly the batteries were built into a wooden box of some kind presumably with a liner of some kind that could tolerate the acid.
> 
> They had a jig and it would hold the plates in a row zinc then lead than zinc and the jumpers would be soldered on with a big giant soldering iron to connect them together depending on the voltage needed.
> 
> Then they would pour acid back in, put the cover on top, and pouring molten tar around the perimeter to seal it all up.
> 
> How he came to own the battery shop was that he worked there part-time to help and the owner "ran away with a girl", and he just kept the business going and eventually by default became the owner.
> 
> I wish I could find any kind of Records on this and I did look in the projo archives but wasn't able to find anything.
> 
> 
> 
>> On August 12, 2019 12:33:15 PM David Crowell <ka1edp at yahoo.com> wrote:
>> 
>> Hi Chris,
>> 
>> There were a couple of reasons for the rheostat. First it would be used to adjust the volume. The other reason had to do with the batteries. 1920's sets used a lead-acid storage battery to power the filaments. The battery would need to be hauled down to the local gas station to be recharged. When the battery was freshly charged, the rheostat was turned down low and as the battery got weak, the rheostat would be turned up. This way, the battery charge lasted longer.
>> 
>> The two tube unit you got may very well be a "two step" amplifier. The  photos I've attached are a two box set I picked up 30 years ago at a house sale. The left hand box is a tuner (no tubes). the right had box has 4 tubes. The first tube is a "grid-leak" detector and the other three are a "three step" amplifier. The 4 binding posts opposite each other would connect one box to the other.
>> 
>> If you look closely, you can see that each tube has it's own rheostat to adjust the filament. The 4 circles of holes above the knobs allowed the operator to see how bright the tubes were lit up. keeping the filament voltage  as low as possible extended the life of both the battery and the tubes which were expensive.
>> 
>> I haven't opened these boxes up in years. I should to see what is inside. I have a paper with base diagrams for antique tubes if you need it. I expect to be on hand this Saturday. 
>> 
>> 73, Dave
>> 
>> 
>> On Monday, August 12, 2019, 11:42:44 AM EDT, Chris Prata <chrisprata at live.com> wrote:
>> 
>> 
>> 
>> Hi Dave that is the same unit and I realize that you may have just taught me something which I did not know - that the filament voltage can be varied to adjust the gain between the Grid and plate, if I'm understanding what you said correctly.
>> 
>> I would like to see a curve on that, as there must be a beginning and an end and a curve in between to how far you can go with that.
>> 
>> Chris
>> 
>> 
>> 
>> 
> 
> 
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