Hi John

Of course, there's a lot to be gained by narrowing the BW, so I ran ARGO

at

60 sec/dot, and had to crank in another 13 dB to kill HBG. There's a
considerable time lag in making such measurements, so fading sets some
limits on accuracy. But I did end up barely being able to see the signal
at -77 dB. Interesting, eh?

Very interesting indeed. Your method is quite a standard method of making
level measurements if the meter on the receiver is not accurate and I can
see no fault in it.

One possible objection to the method is that the absolute value of the
attenuation is probably in error due to the output impedance of the preamp
and the input impedance of the receiver not being 50 ohms. While that's
true, at least the changes in attenuation needed to kill the signal under
various band conditions would still be valid. This will enable me to track
things on a day-to-day basis.

You need some S/W that can record signal level ( I think some has already
been suggested) so that it can be left unattended once the attenuation level
had been established.
I have heard that CFH may also be on, or near, 73.3kHz. Are you able to
confirm that it is really Rugby that you are hearing? I guess that with your
directional loop antenna you will have that question already resolved.
Once you have some data it can be compared with Alan's propagation info to
see if anything of interest emerges.

Regards,
Peter, G3LDO

e-mail <[email protected]>

Web <http://web.ukonline.co.uk/g3ldo>