On 4 Sep 2003 08:50:24 -0700, (Qas) wrote:

Hi,
I am new to ham radio. Well I found lots of QRP receiver circuit on
web, I tried to build some. Everything going to be OK, except making
coil inductors. I don't know how to calculate them, with type I need
(air core or slug tuned), what a difference between coil and RF choke.
Let's assume I need a 100uH coil. How to star making it. I looked for
factory made coil at my radio shack store, but I only found bobbin for
coil.

If you know any interesting link on this topic, please let me know.
I'll appreciate any comment or help.

Thanks in advice,
Edgar
73


Check out this website, its quite useful and has many different java
calculators for finding the inductance values of both toroid and air
form coils. I used the calculator to create a 3uh coil and it came out
pretty darn close to what I intended. (never bridge measured it
though)

http://eweb.chemeng.ed.ac.uk/jack/radio/projsoft.html

mike