[Amps] 10dB and propagation

K3BU at aol.com K3BU at aol.com
Sun Feb 6 18:08:32 EST 2005


In a message dated 2/6/2005 9:57:54 AM Eastern Standard Time, 
k7fm at teleport.com writes:
>>I used to wonder how come I could use a tri-band beam, advertised at 8 db
gain, and an amplifier advertised at 1500 watts and yet be 15 db down from
other local stations who were using 3 element mono-banders.  Since the power
limit is 1500 watts, they would naturally have been running the same power
as me.

This non-linear ionospheric amplification must therefore have been the
explanation.  I had been puzzled for years.  They obviously lived in such a
duct, while I did not.<<

You guys might try to poke fun at this. But there are many factors 
contributing to signal levels received at the other end. Antenna pattern, local ground 
conditions, terrain and propagation conditions.  VHFers know about ducting on 
VHF between W6 and KH6, you drive up the hill and you can find spot where your 
signal (few watts) will hit it and you QSO with KH6. You go few hundred feet 
up or down and you lose it. 

Skewed and varying (high) angle propagation with spotlight effect is now 
"normal" on 160m, where earlier when I mentioned it, I was "kockoo".

Yuri, K3BU.us


More information about the Amps mailing list