From: "Gary - G4WGT" <g4wgt@tiscali.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <9051.82.161.81.65.1230483108.squirrel@webmail.xs4all.nl> <000501c96910$9d6f9aa0$4201a8c0@home>
Date: Sun, 28 Dec 2008 18:45:04 -0000
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Subject: RE: LF: 500KHz QSB
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Jim, LF,

I have the very handbook - Vol II "Wireless Telegraphy Theory"

I didn't even think of looking there, a very good section on propagation.
Probably many other things if I care to look. I only got it as a collectable
item relating to radio communications.

I must be careful though as it is very flimsy now with age.

73

Gary - G4WGT.

-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org
[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of James Moritz
Sent: 28 December 2008 17:21
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: 500KHz QSB

Dear Gary, LF Group,

Quoting from the Propagation chapter of the Admiralty Handbook of Wireless
Telegraphy 1938 edition:

"It is usually observed that the different frequency components of a
modulated wave fade in a manner which is independent of each other. This has
been termed "selective fading"...
...The use of ICW ["interrupted continuous wave" i.e. modulated CW as with
the NDBs] at H/F is therefore a means of combating fading in telegraphic
work."

So  the idea of increasing the signal bandwidth to combat selective fading
is not entirely new... MCW beacons anyone?

Cheers, Jim Moritz
73 de M0BMU