*****Oh no, Phil. Not at all. But I have no idea how to post it
online. Am I supposed to
scan it in first? Or....? I got the schematic from a old dairy kept
by my uncle. He passed
away years ago. He was an electrician and a radio hobbist. I guess he
kep the schematic
himself for a long time, or perhaps he once wanted to buid it himslef,
but did. Now my
kids are interested in building it. Best wishes to you! Dan
Hi, Dan. I like the idea of working from the diary to discover what
your uncle was thinking. But there are a couple of gotchas here.
First off, many ideas jotted down in notebooks aren't really
complete. I know many of mine aren't. He may have been just writing
in an idea to fill out later.
Also, an old AM radio design with less than 5 transistors is probably
taking a shortcut somewhere. Not necessarily a bad thing, but even if
it's a guaranteed working circuit he just copied down, it's probably
relying on a trick we'd have to see to evaluate choice of
transistors. I'd hate to see you and the kids go to the work of
trying to put something together from scratch and have it fail because
of some free newsgroup advice. ;-)
As a bonus, layout in RF circuits is pretty important, to prevent
unwanted oscillations in the amplifier stages. Working from a
schematic only, as a relative newbie you might end up going down a
rabbit trail there, too.
Old educational transistor radio kits are still being made which are
guaranteed to work and provide a good educational experience. You
could do worse than getting the Elenco AM-550TK (5 transistor, no ICs,
old-style transistor radio kit with good educational brochure
explaining the circuit), building it with the kids, and then raising a
glass to the memory of their dad's uncle when they turn it on and it
works. Similar in many ways, you get all the parts you need, almost
guaranteed success if you have any soldering and assembly skill, and
after you're done, you'll understand a lot more about his idea (and
possibly where the shortcut is).
http://www.elenco.com/
Good luck
Chris