[Milsurplus] was T2X3; now auto-radio tubes

[Bob Camp]

Hi

A *very* long time ago my main portable radio was the Motorola 
commercial version of the VRC-19 stuff. The poor thing had a bunch of 
batteries in the bottom of it and little plug in modules with the plug 
in tubes in them. Pretty much the same construction as a VRC-19 only 
set up to be portable.

My recollection is that the filament batteries got down past 1.3 volts 
pretty darn fast.  They were all standard carbon zinc cells so there 
was nothing very mysterious about the process. I'm sure the tubes were 
designed with something like a D cell as the filament supply. They 
would not detonate when 1.5 volts was applied but they expected to live 
most of their life at a voltage a lot closer to 1.1 volts than 1.4 or 
1.5. I don't remember any significant degradation in performance until 
the batteries got fairly well below a volt.

	Take Care

		Bob Camp
		KB8TQ

On Jun 25, 2004, at 3:45 PM, WA5CAB at cs.com wrote:

> e & Group,
>
> I don't have it in writing but the 1.4V (and 2.8V) ratings for the 
> battery
> tubes was probably to give reasonably decent operation over the 
> discharge cycle
> of the carbon-zinc (LaClanche cell) which has an operating discharge 
> range of
> 1.5 to 0.75 volts.  Now why the rating isn't say 1.2V which would be 
> more
> nearly in the center of that range I haven't a clue.
>
> Four of the large Ignition cells were also used to run the filaments 
> of the
> BC-221.
>
> In a message dated 6/25/2004 2:36:31 PM Central Daylight Time,
> ejones at hiwaay.net writes:
>> BTW, there ARE a whole passel of tubes with 1.4v fils: the oldies 
>> used in
>> battery radios in the 30's-50's.  Their filaments were designed for 
>> the
>> "A" -sized LeClanche cell, the 1.5 volt monster also used to power
>> telegraph/telephone systems.  I recall finding old ones in the 
>> battery box
>> aside
>> the local L&N railroad; and I used one myself to heat the glow plug 
>> in a toy
>> aircraft engine.  Ironically, I never used one in a radio!
>
> Robert Downs - Houston
> <http://www.wa5cab.com> (Web Store)
> <wa5cab at cs.com> (Primary email)
> <wa5cab at houston.rr.com> (Backup email)
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