On 20/04/2019 20:57, Bob Eager wrote:
On Sat, 20 Apr 2019 15:34:58 +0100, Steve Walker wrote:

For some reason I'd always thought that the PP3 9-volt battery was
called a PP9 (9 for 9 volts) rather than PP3. I also remember a 4.5V
rectangular battery with screw terminals - the screw part was a stepped
conical shape, IIRC; that's not listed on the Wikipedia page.

If that is the one I remember, my grandparents doorbell ran off one of
those and the battery sat on the wood of the doorframe.

I had a transistor radio that used TWO of them!

http://vintage-radios-london.co.uk/V...-TP85-LWMW-FM-
Portable-Transistor-Radio

Note that's two PP9s, not bell batteries.

--
Max Demian