20 Mar
2007
20 Mar
'07
9:49 p.m.
On 20 Mar 2007 at 20:27, Brad Parker wrote:
[possibly off topic, but what isn't these days? :-)]
When I was a kid I had a book, I think it was called something like
"single transistor projects". As I recall it was full of lots of
simple circuits featuring a single transistor.
(or who knows, maybe it was 101 transistor project; I think I was
in 4th grade at the time - late '60s)
anyway, one was a single transistor FM radio. I just remember it had a
single FET, a coil, a cap, some discreets. I think it told how to
wind the coil "in the air".
Does anyone remember such a book?
I figure if anyone one would, it would be someone here...
seems like a fun thing to build now days with my son.
Good on ya, Brad! I built my first receiver with my dad--using a
1G4GT, back when one could still buy "B" batteries. Many many years
later, my father long gone--I still remember it fondly.
I recall that he told me how, when he was a boy, he built his first
non-crystal radio receiver using an 01A.
The first transistor that I ever bought (not scavenged) was an RCA
2N109. I used a subminiature tube socket (the type of wire-lead tube
used in hearing aids) scavenged from a Motorola Pixiie radio. You
had to use a socket with the 2N109--the leads were only about 1/4"
long.
I remember a book for boys with a bunch of transistor projects--all
using 2N107 (PNP) and 2N170 (NPN) transistors, or CK722/CK721
equivalents.
Much to my surprise, someone is still selling 2N107s:
http://semiconductormuseum.com/MuseumStore/MuseumStore_2N107_Index.htm
Other semiconductors are fun to fool with in simple circuits; tunnel
diodes, UJTs, etc. are worth checking into.
Right now, I'm trying to recall a circuit I once saw of a one-
transistor superhet. The same transistor was used for the self-
exciting mixer and a stage of AF amplification. Detection was done
with a diode. Does this ring any bells with anyone--or am I
hallucinating again?
At any rate, if you ever run into any of the 1950's Alfred P. Morgan
"Electronics book for boys" at a library sale, grab it and give it to
your son--he'll enjoy it. Morgan included projects for both tubes
and transistors.
Cheers,
Chuck