Topband: Moon and the Ionosphere : YO3FFF

[Nick Hall-Patch]

At 19:21 17/03/2007, Tom Rauch wrote:
>How could we record the signal level, anyone know?
>
>73 Tom

I'm not sure how badly I want to display the gaps in my knowledge 
about this problem to those on the list, Tom!

My feeling is that the least of the worries is automated recording of 
signal strength; it's making sure that the signal strengths recorded 
are unaffected by any factors other than the propagation mechanism 
you're trying to observe, as you've already pointed out.

Unless I misunderstand your question, and am belaboring the obvious, 
here's how I've recorded signal strengths for the better part of 10 
years (a more detailed explanation is 
at  http://www3.telus.net/7dxr/333/333descr.html and in the 
July-August 2001 QEX)   I'll not claim great technical depth for the 
article, and it dates back to the late 90s, but basically, somebody 
writes a little program that tunes a computer controlled receiver  or 
transceiver through a serial port and reads the signal strength back 
from the receiver, recording it in a file with a time stamp.   I'm 
sure it could be done in a more sophisticated fashion now (FFTs from 
the output of a software defined radio for example), but this method 
has recorded me the best part of a sunspot cycle's worth of data.

I've been surprised at how well Sprectrum Lab 
(http://www.qsl.net/dl4yhf/spectra1.html) can give you relative 
signal levels on a discrete frequency by using the strength of a 
heterodyne on that received carrier,  fed from your receiver's audio 
output into a sound card (AGC off on the receiver of 
course).  Recording capability is included,  you can "see" signals 
you can't hear, and it's free.

best wishes,

Nick
VE7DXR





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Nick Hall-Patch
Victoria, B.C.
Canada

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