[NLRS] noise figure

[Ronald Bergantzel]

Well , Hello Kirk and all ! I have not seen ANY need for AGC on 144 EME ....... I turn off the AGC on either the TS20000X or the FT991 ( both transceivers have the receive line separated internally ) when on 144 EME - I am running a single  modified cc 17B2  with full azimuth and elevation ability , thru 51 ft of LDF4-50 , then thru a pair of relays to my homebrew cavity input preamp @ 0.24db NF and 26 db gain . I am also using a PA3CSG designed GS35 Cavity amplifier running full legal limit ( I have designed and built this particular system including the power supply , biasing , T/R relays , etc to run at 3kw so I  have ample 'headroom' running digital modes at 1500 watts with the  full duty cycles that are required by digital modes , contesting , etc  ) and have worked over 250 + QSOs off the moon on 144 mhz  . Over 80% of the time, I can work anyone I hear or copy with this setup - its all in optimizing your system ........ 

   

 On Tuesday, September 6, 2016 11:05 AM, "ky0o at kc.rr.com" <ky0o at kc.rr.com> wrote:
 

 

Hello, there, kirk.  The other thing I do is adjust the RF gain with the
af gain maxed out.  That allows the preamp to lower the noise figure
because you're adjusting for best heard signal.  This also allows you to
point better, because your AGC isn't being plastered to the wall.  I
also have put an MFJ 784B in line between the speaker and the radio. 
That cuts down on bothersome noise, and I use high-quality headphones to
improve hearing ability.  My rig is a Kenwood 2000X  And, my preamp is
in the shack between an 18 triple x at fifty feet and whatever feedline
is between the preamp and the antenna.  I hear stations consistently at
three hundred miles.

Thank you,

Craig, KY0O

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