Crystal Radios (was Re: List spammer ID'd)

From: Dwight Elvey <elvey_at_hal.com>
Date: Wed Mar 28 13:27:49 2001

Hi
 One other thing that one can do to improve the sensitivity
of a crystal set is to slightly forward bias the diode.
I used a 100K pot across a 1.5 volt battery. I used a
10K isolation resistor and used a blocking capacitor
when using a dynamic head phone.
 I also made traps for the strong stations ( I had two
that were real close ) so that I could get some of the weaker
ones. I also found an old scrap radio that used a
TRF front stages. I used this to make a two stage tuner
that improved the selectivity quite a bit. I wish
I'd save some of this stuff but it always seemed like
the next project needed the parts used in the first.
 My favorite was a short wave regenerative set made
with a dual triode. I got the schematic from the "Boys
Life" magazine ( Boy Scout magazine ).
Dwight
Received on Wed Mar 28 2001 - 13:27:49 BST