[Elecraft] K3 question

[David Gilbert]

There is a very simple answer for that.  All you care about for receive 
is signal-to-noise ratio on YOUR end of the path... efficiency is 
irrelevant because there is usually plenty of gain in any modern 
receiver, and if there isn't enough gain a simple low noise preamp fills 
in nicely.  That means any antenna with a good enough pattern (or the 
right polarity) to discriminate against noise will usually make a good 
receive antenna.   Beverages and various loop configurations (K9AY, 
pennants, etc) work well for that but they are very lossy and don't make 
good transmit antennas.

For transmit, you care about signal-to-noise ratio on the FAR end of the 
path, and since you have no control over the noise over there you can 
only try to optimize your signal strength.  The efficiency of your 
transmit antenna/feedline/etc is the first priority, with directional 
gain from pattern also being desirable.  For some bands, you can get 
both transmit efficiency and receive noise discrimination from the same 
antenna, but for the low bands that is pretty difficult to do without 
devoting the space and money to some sort of monster array.

For good antenna efficiency you almost always need size or height that 
is an appreciable percent of a wavelength ... for good pattern you often 
don't.

Dave   AB7E




On 2/29/2012 4:51 AM, Monty Shultes wrote:
> Of course I don't understand why you would receive better on one antenna and transmit better on another.
>
>