On Fri, 19 Mar 2004 17:46:43 GMT, "Harold E. Johnson"
wrote:


I don't think you can get away
with short cuts at RF, especially if you're a non-expert.

3 MHz is practically DC. Why don't you ask one of your friends at the BBC to
build it for you.

I was told 40Mhz is "practically DC" too. I guess it depends on where
you're coming from.
Actually I've dumped the factory inductor as suggested by Tom and
wound-up a large, air core job on 15mm plastic water pipe. It's made
a big difference. I'm happy to report I've now got the 5th! Could be a
little cleaner but who cares? Tom made a big deal out of the
importance of high-Q so it was the obvious thing to try. Fortunately,
it's worked. God knows how I'm going to squeeze this monster coil onto
the board, though! :-|
Can I infer from this experience that SMD inductors of over a few uH
are a waste of time?
--

The BBC: Licensed at public expense to spread lies.