[Elecraft] [K3] 150 watt "boots" for 160m

[Bill W4ZV]

>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
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