21 Mar
2007
21 Mar
'07
5:07 p.m.
Good on ya, Brad! I built my first receiver with my
dad--using a
I still haev the first radio I built -- 35 years ago, alas it wsa
transistorised . It was the well-known 'Ladybird book' design, using an
OC45 as a regenrative detector and a couple of OC71s as audio stages.
1G4GT, back when one could still buy "B"
batteries. Many many years
These days, you can get 9V (PP3, 006P, 6F22, whatever you call them)
batteries very cheaply in the 'Everything's a pound' shops (I assume you
have similar shops that sell all sorts of things for a dollar a time). 5
to 10 of those in series will work as B battery, of couse.
Personally, I'd use a mains supply. a 30V transformer (15-0-15, ignoring
the centre tape or a pair of 15V windings in series) feeding a voltage
doubler rectifier (2 diodes, 2 capacitors) will give about 85V, ideal for
most 'battery' valve circuits.
-tony