On Dec 11, 9:18 am, cmor wrote:
I'm trying to create a largish ferrite receiver antenna tuned
exclusively to the 457khz range. I was going to get the ferrite rod
from he

http://www.stormwise.com/page26.htm

As I only need the single frequency I was wondering if it was more
effective to make a self-resonant antenna?, or does a capacitor not
decrease quality of the single?

Secondlly, I have very little experience in the radio world, and was
considering following am radio plans similar to this to attach my
antenna to:http://www.stormwise.com/page56.htm

Just swapping the variable capacitor for a fixed one tuned to my
frequency.

Is this the optimal way to get the strongest signal? Can anyone point
me in a direction to get more information on how to build such a
receiver? Most important is the range of the antenna in picking up
very weak signals.

Thanks,
Chris

What specific kind of signals are you trying to pick up, and what is
it that will prevent you from hearing them? That is, if the signals
are buried in atmospheric noise, a more "sensitive" antenna that also
picks up more noise as well as more signal isn't going to help the
signal-to-noise ratio. For that, you may need to use some additional
knowledge about the signal that you can use to differentiate it from
the noise. At 457kHz, atmospheric noise is very high amplitude, and
it doesn't take much of an antenna plus receiver to get all the signal
that will do you any good.

On the other hand, if the thing that keeps you from hearing the
desired signal is an interfering signal, the null of a loop (or
ferrite rod) antenna can be used to get rid of that signal that comes
from one direction (which lets you listen more easily to the desired
signal, provided your desired signal isn't coming from the same
direction).

Cheers,
Tom