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[TowerTalk] 2dB or not 2 be dB

To: <towertalk@contesting.com>
Subject: [TowerTalk] 2dB or not 2 be dB
From: K7GCO@aol.com (K7GCO@aol.com)
Date: Fri, 7 Sep 2001 12:14:08 EDT

 In a message dated 9/7/01 7:38:14 AM Pacific Daylight Time, 2@vc.net 
 writes:<< 
  > On HF/MF skywave, is a 58% increase in power out (2db) noticable at the 
Rx 
  end? 
    My guess is that for moonbounce, 2db would make the difference between 
  being heard or not.  However, in my double-blind test of 40m daytime 
  skywave with normal QSB,, no one could see the difference on their 
  S-meter. cheers
   R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.  
   >>
 I would certainly agree with this in particular with a pulsating SSB signal 
 on S meter swing and AVC action.  In AM days you could see 2 dB on the S 
 meter on an A/B test.  It just occurred to me that 2 dB less gain of an 
 antenna system used for moon bounce would be a 4 dB loss as it's also used 
 for receive of transmitted signal from the same antenna.
 
 I think that a -2 dB will be seen the most in a contest of a lower 
percentage 
 intelligence and more repeats etc. 
 
 There is another way to measure relative and small differences in antenna 
 gain on a A/B test on SSB I've used since SSB came into use.  Turn the RF 
 down and the audio gain up and do the A/B test.  You will be able to HEAR 
 very small differences in audio level with a SSB signals as the audio level 
 your ear hears can be controlled and the AVC is disabled.  Your ear has a 
AVC 
 level affect also I'm told.  Try it. You will be able to SEE very small 
 differences in comparative signal strength by connecting a scope to the 
 speaker output set for vertical deflection. 
 
 There is another affect on the ear from excessive volume.  Guns can be fired 
 so fast that it sounds like one shot.  Orvo Ajala could draw and double fire 
 a Colt SA 45 sweeping his thumb and little finger across the hammer spur so 
 fast "it sounded like one shot". He's the one who taught Jim Arness the fast 
 draw.  On Gunsmoke he was the one in the opening action that had a shoot out 
 with Matt Dillion. At the Worlds Fair in 65 Orvo had a stand here.  He would 
 let you hold a cocked 45 on him with blanks and he would draw and fire 
before 
 you could just react and pull the trigger.  I beat him one time. His draw 
and 
 fire time was faster than many others reaction time. Rule of thumb--always 
 draw first if you ever expect to draw again.
 
 At a fast draw contest in Vegas about then the winning time was .22 seconds 
 from a signal light to fire.
 
 Your eyes don't cut off immediately when light shuts off either.  That's why 
 moving pictures look like a continuous source of light.  k7gco


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