Re: 150 watt "boots" for 160m

Posted by Bill W4ZV on Dec 11, 2009; 9:58pm
URL: http://elecraft.85.s1.nabble.com/150-watt-boots-for-160m-tp4151943p4154008.html

>From 100 to 150, for 1.7 dB, when Bell Laboratories research (with
huge capital investment and telephone maintenance dollars on the line)
determined that 3 dB was the signal strength change discernment for
most people?

I'm not sure who said 3 dB was the minimum detectable by a listener but I believe it's incorrect.  1 dB "roughly matched the smallest attenuation detectable to an average listener".  (see below)

"The decibel originates from methods used to quantify reductions in audio levels in telephone circuits. These losses were originally measured in units of Miles of Standard Cable (MSC), where 1 MSC corresponded to the loss of power over a 1 mile (approximately 1.6 km) length of standard telephone cable at a frequency of 5000 radians per second (795.8 Hz) and roughly matched the smallest attenuation detectable to an average listener. Standard telephone cable was defined as "a cable having uniformly distributed resistances of 88 ohms per loop mile and uniformly distributed shunt capacitance of .054 microfarad per mile" (approximately 19 gauge)."

http://en.wikipedia.org/wiki/Decibel#History

73,  Bill