[Elecraft] K3 Buffer Mod

[Larry Phipps]

The gain can easily be made up, and is, but NF can not be made up in later stages once it is set in an earlier one. Anything connected to the IF port can only increase NF, no matter how quiet it is or how much gain it has. The easiest way to improve composite NF would be to add a strong, low noise preamp with adequate gain AHEAD of the K3, but that would compromise IMD.

There would be no reason to un-modify a K3 to work with any kind of panadapter connected to the IF port. 

73,
Larry N8LP



Message: 37
Date: Fri, 22 Aug 2008 16:50:46 -0400
From: Don Wilhelm <w3fpr at embarqmail.com>
Subject: Re: [Elecraft] K3 Buffer Mod
To: Jerry Flanders <jeflanders at comcast.net>
Cc: elecraft at mailman.qth.net
Message-ID: <48AF26A6.4070907 at embarqmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Jerry,

I do agree with you.  There is a requirement for an isolation amplifier 
anyhow, so I do not understand why the -17.7 dB cannot be made up in the 
isolation amplifier if the device to be driven needs  input at the same 
level as the antenna signal.

Should Elecraft ever come out with a device (Panadapter?) that is 
designed to connect to the IF out at the level it currently is designed 
for, any K3 that has been modified will require that the modification be 
  removed.

73,
Don W3FPR

>