25 Apr
2005
25 Apr
'05
9:57 a.m.
From: "Stan Barr" <stanb at
dial.pipex.com>
Hi,
Tony Duell said:
Hi Stan
I've done similar. I've taken one of those small 100W
inverters and rewound the transformer on it to provide
all the voltages for my older battery powered Atwater
set. It just runs from a 12 volt gel cell. I tapped
of the primary to provide the filament voltage and
used the secondary with tape to provide the rest.
As I recall, there was one -C and two +B voltages.
I used no regulation, just used the right rinding
ratios. One has to remember, these old radios
were made to run form carbon-zinc cell in most cases.
I did put a pot on my C cell. The original was -4.5v
but I found that it works better, with less distortion,
when set at about -3.5v.
Dwight
I must try the circuit that was in Elektor a couple of months back to get
90V from low-voltage batteries.
See http://hometown.aol.co.uk/kitradioco/uk.htm for a commercial one,
it even looks like a battery. But IIRC you're like me - you don't like
_buying_ things you can make!