Any info on 10.5V grid bias battery?
 

I can't seem to find any pictures of grid bias batteries of the 30's and 40's that at least offer up to 10.5V, with tappings.

I know what size the battery box is for one of them: 6" x 1" x 2.5" roughly.

Was there a 10.5V battery or would it have been bigger, just not using all of it?

Re: Any info on 10.5V grid biad battery?
 

I thought the max was 9.5Volts?

Re: Any info on 10.5V grid bias battery?
 

?? There is no maximum.
These are batteries made from 1.5V cells in series, as many as needed.

I know of grid bias up to 21V !

I was hoping to find out whether the 10.5V ones were actually bigger or exactly that size and ideally see a photo of one.

Re: Any info on 10.5V grid bias battery?
 

Looking in a 1930-31 'Northern Radio and Cycle Supplies' catalogue, there are listings for a few giving higher voltages than 9.5V, Grosvenor has a range up to 24V in 3V steps, Siemens up to 16.5V in 1.5V steps and Ever Ready and Pertrix 15V in 1.5V steps, unfortunately no pictures of the grid bias ones only the HT batteries.

John

Re: Any info on 10.5V grid bias battery?
 

I don't know of a 10.5 volt (max) GB battery that was made, that said it would probably fit into a 6" slot:

http://www.royalsignals.org.uk/kd4hs...-front-ref.jpg

Lawrence.

Re: Any info on 10.5V grid bias battery?
 

Yes, I saw that picture and deduced the same.

Grid bias batteries that provided at least 10.5V and were less than 6" long were most certainly made. I just don't know if they were 10.5V exactly (plus lower tappings) or bigger.

Re: Any info on 10.5V grid bias battery?
 

I can tell you the sizes of the ones I mentioned in my post but I cant find any 10.5V ones.,

Grosvenor 24V = 13-3/8" x 7/8" x 3"
Siemens 16.5V = 9-1/8" x 1" x 3-1/8"
Ever Ready 16V = 9-1/8" x 7/8" x 3-1/4"
Pertrix 15V = 8-1/4" x 15/16" x 2-15/16"

The Ever Ready is actually listed as 16V not 15V as I posted.

John

Re: Any info on 10.5V grid bias battery?
 

Ten new 1.5V cells could easily add up to 16V.......

Re: Any info on 10.5V grid bias battery?
 

I certainly stand corrected again this week,I really thought they never went above 9.5V and of course that is all I have ever seen till today's pictures.

Re: Any info on 10.5V grid bias battery?
 

I remembered this thread when I met this fellow today, still clipped inside an Osram 4 New Music Magnet.

Paul

Re: Any info on 10.5V grid bias battery?
 

Possibly still got a bit of voltage too left.

Re: Any info on 10.5V grid bias battery?
 

10 volts end to end, slowly dropping, when measured by my trusty Fluke 8000A (10M input impedance).

Re: Any info on 10.5V grid bias battery?
 

Well, that one must be old enough to be zinc cased and pitch topped off. So, stick it in the bottom oven by the fire (upright of course) and watch the voltage come up. Always did that with the mandatory Christmas torch off one of the aunties. Going back 70 years though.
Les.