[ARC5] Bias Battery

[Scott Robinson]

I actually suspect that the main appeal in 1936 was that, in a 
triode/diode such as a 6Q7  tube with a common cathode, you can't 
cathode bias the triode without messing up the detection process and 
AVC. The eventual solution to this was using self-bias via a 5 to 10 meg 
grid leak resistor.

Peace,
Scott

On 2/4/20 7:02 PM, Richard Knoppow wrote:
>    One can use any type of cell for bias but mercury cells had the 
> advantage of very long life under light load and very constant voltage. 
> They are 1.35 volts per cell. Alkaline or carbon/zinc cells are about 
> 1.5 volts per cell but do not last nearly as long as mercury cells. The 
> problem, of course, is that mercury cells are  no longer available 
> because they are an environmental hazard. Other kinds of cells will 
> replace them, with sometimes some juggling, but nothing else has quite 
> the same properties. Bias batteries have the advantage of not dropping 
> the B+ like a cathode resistor and constant voltage.
> 
> 
> On 2/4/2020 3:32 PM, Robert Eleazer wrote:
>> I took a look ath the receiver section of a GRC-9.  That set uses a 
>> 4.5 volt bias battery, with the positive side hooked to chassis 
>> ground.  It was comprised of three "button" cells in series, so I 
>> assume they were 1.5 VDC each.
>>
>> Wayne
>> WB5WSV
>>
>