Topband: Back Scatter ?

[K1FZ-Bruce]

 Nick.  The overall timing was irregular, but the slope of QSB took a couple of seconds. 
This was at local noon time, so had not considered other  stations. 
 
We do not have high power BCB stations here in Maine. Only a little over 1 million residents that widely  placed. 
Some  1 KW, 5 KW BCB stations.  It is however possible in mid-coast Maine to hear WBZ 1030 KHZ in Boston, at mid-day... 
 
Thanks for the heads up. Appreciate your input. Will do more testing
 
 
73
Bruce-K1FZ
 

On Thu, 16 Jun 2016 05:41:41 +0000, Nick Hall-Patch  wrote:

      Hi Bruce,

Does the QSB vary regularly at say a 0.5Hz or 1Hz rate? Could it be 
another station on the channel that is not exactly the same 
frequency, not strong enough to deliver audio, but strong enough to 
create a sub-audible beat note?

If it is irregular, shouldn't the traditional explanation of a 
touch of high angle skywave interfering with the small amount of 
ground wave remaining after nulling the station be sufficient to 
explain the QSB?

73,

Nick

VE7DXR

At 15:20 15-06-16, K1FZ-Bruce wrote:

Been working to optimize the F/B on some antennas, using ground 
wave stations in the upper BCB band. Noticed that some weaker ~20 
mile distant 5 KW stations that the back (reverse) signal
has QSB on them. Think we used to call it back scatter years ago. 
Some are down in the noise and QSB up to about 1 S unit. 

We used to think back scatter was reflective variations in the 
ionosphere. Is there any more recent information ? Maybe carbon in 
varying cloud layers ?

73
Bruce-k1fz

http://www.qsl.net/k1fz/beverage_antenna.html

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