[Amps] 10 DB increase

[Michael Tope]

----- Original Message ----- 
From: "R.Measures" <r at somis.org>
 
> On Feb 4, 2005, at 4:03 PM, Radioal wrote:
> 
> > A 10 dB increase in power will be propagated as a 10 dB increase - 
> > regardless of the state of the ionosphere, antennas, locations, etc.
> 
> I used to think that this was the case until I sold the original 
> Plywood Box/8170 amplifier.  Even though I had measured the amplifier's 
> voltage-gain as x10 with an oscilloscope (20db power-gain), but on the 
> air,  I measured 20 - 23db with my calibrated S-meter.  Other people 
> with calibrated S-meters reported the same crazy thing.  Others who saw 
> the 23db change said that Stanford (University) Research Institute had 
> observed something similar during their ionospheric heating research 
> project

Think about the power density in the ionosphere when you 
spread 20 KW over a half sphere 80 or 90 KM in diameter. 
You are talking a sphere of surface area on the order of 
8*10^9 meters^2, so power density in that case is 
approximately 20E3/8e9 = 1.3e-6 Watts/meter^2 (e.g. 
about 1 microwatt/meter-squared). An 8171 amp going to 
a dipole would be roughly equivalent to 1 HAARP element 
without any of the antenna gain. I would suspect S-meter 
inaccuracy and the effects of ionoshperic fading before 
I would suspect some kind of plasma heating. A good test 
would be to chop the 8171output at 10 or 20 Hz rate between 
100 watts and full ouput and then look at the audio output 
of the receiver with the AGC off on a good scope. At that 
rate, the changes in power would be faster than the fading. 
Of course, if the time constant of the ionospheric effect were 
slower than 50 or 100ms, you wouldn't see it with this 
method (you would have to lower the chop rate at the risk
of confounding the data with fading effects).  

73 de Mike, W4EF............