Yes, I'm sure.

It's a 60 foot run to the house, which is relatively short in terms of
wavelength.

I am feeding it with a balanced line (actually both conductors
floating). So, the pickup by the line to the house should be quite
minimal. I've tried 300 ohm twinlead and cat5 twisted wire cable. Both
work well.

Would never use anything as crude as coax for something like this, it
is just asking for trouble.



On Mon, 24 Oct 2005 08:32:58 +0300, Paul Keinanen
wrote:

On Sun, 23 Oct 2005 20:34:17 -0400, TRABEM wrote:

I am going to feed this into a quadrature front end, which has a
problem with harmonics getting into the receiver. My hope is to use
the loop as the sole tuning for the front end of the receiver, so
maintaining the highest possible Q is imperative.

Before going to such extreme measures, are you absolutely sure that
the "harmonics" are entering the receiver from the actual loop due to
insufficient Q and _not_ sneaking in through the cable shield, power
supply lines etc. or other antenna effects ?

Even if you have a single strong unwanted signal at some harmonic
frequency, taking it out with a high-Q notch filter prior to the
mixer(s) would be easier. An isolation stage (emitter follower etc.)
might be needed between the receiver loop and the notch filter to
prevent too much interaction.


Paul, there are no mixers. It's not a superhet. No mixers, no diode
detector, no tuned circuit between the antenna and the detector. An
active component anywhere between the antenna and the detector defeats
the purpose of a quadrature detector...and, since we don't need an rf
stage at all, the receiver is much cleaner than conventional superhets
ever could hope to be.

Strong signals on adjacent frequencies that force their way into the
front end just end up being cancelled out by the quadrature detector
(witht he exception of harmonically related signals)...which is
another advantage.

The audio is remarkably clean and crisp.

One would NEVER use any sort of a preamp in a quadrature based
receiver.
Regards,

T