On 3/18/2012 12:06 PM, James Rodenkirch wrote:
> disallow QRP operations
The point was not to disallow QRP, but to observe that when noise levels
are high a QRP signal is not likely to be heard.
Three important facts of life that every QRPer must firmly understand
are that 1) when you're running QRP the other station's receiving
system is doing 99% of the work, and 2) your success is limited by the
other station's noise level, and 3) 5W gives away 13dB ( two S-units) of
noise as compared to 100W and 25dB (four S-units) as compared to 1.5kW.
When you give that much away, you're only going to work guys in quiet
locations with Beverages. During a recent 160M contest a QRP VY2 called
me when I was running. He has a big antenna farm and I've got a good
Beverage pointed at him, and he was just barely readable.
Another important consideration with QRP is that propagation between any
two points often varies by 30-40dB over the course of an evening. When
you're running QRO you can make Qs when propagation is well below peak,
while with QRP you've got to make your Q when conditions are just right,
and the other guy may have gone to bed by then. :) When I lived in
Chicago I ran WAE CW QRP. I couldn't work anyone when they were S5 -- I
had to wait until they were S9 or better.
I've run some contests QRP, including some 160M events, but I'm not
enough of a glutton for punishment to do QRP on 160M during my summer. :)
73, Jim K9YC
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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