Topband: FW: The WD8DSB mini-flag antenna (LONG!)

[Jim Brown]

On 2/25/2021 5:16 PM, John Kaufmann via Topband wrote:
> The P3 averages power, not amplitude, so using longer averaging times just
> smooths the display and doesn't reduce random noise.

It has nothing to do with power. Last I looked, the P3 is reading and 
displaying the instantaneous voltage in the IF, and can be calibrated to 
voltage at the input.

I've been doing swept measurements of complex quantities for nearly 40 
years, first at audio frequencies and now at RF. Averaging DOES cause 
random contents of a bin to approach zero (or the noise floor), making 
correlated signals stand out. This has long been well understood.

I the principle to measure the dynamic response of broadcast signal 
processing in a peer-reviewed paper to the Audio Engineering Society in 
1986.  The test signal was a swept sine embedded deep in musical program 
material to the point that it was barely audible to a trained listener, 
and detected by a synchronized swept narrowband detector. Because the 
swept excitation and swept detector are synchronized, the measurement 
produces the complex response of the system, and program material, being 
non-coherent, averages out.

http://k9yc.com/AESPaper-TDS.pdf

73, Jim K9YC