[Elecraft] Analog vs. Digital Front Ends

[Wes (N7WS)]

You're talking about matching, not any frequency selectivity of the wire.  
Thousands of guys swear by a so-called G5RV and 43' verticals (I'm not one of 
them), antennas that aren't resonant on any ham band where they're used.  There 
is absolutely no requirement that a wire be resonant to operate efficiently; 
especially on receive, which is the case at hand. Any frequency selectivity is 
due to the matching network, not anything inherent in the piece of wire.


On 9/16/2015 12:19 PM, Rick Stealey wrote:
> If I'm using my 40 m dipole and go to 80 meters the signals will jump up SIGNIFICANTLY if I switch to my 80 meter antenna.  Several S units.
> Same on 20.
> So, if instead of a single band 40 m dipole I had a 80/40 fan dipole, wouldn't an SDR have to deal with stronger signals in total?
> Same as if we were talking about a Steppir vs a trapped tribander on 10-20 meters.
>
> Rick  K2XT
>
>> To:elecraft at mailman.qth.net
>> From:wes at triconet.org
>> Date: Wed, 16 Sep 2015 08:21:03 -0700
>> Subject: Re: [Elecraft] Analog vs. Digital Front Ends
>>
>> I'm having a hard time understanding where the frequency selectivity of a piece
>> of wire comes from.
>>
>> On 9/16/2015 6:13 AM, Rick Stealey wrote:
>>> And Joe presented a very useful tabulation showing how signals combine.
>>> One thing that we should keep in mind is that single band antennas like Steppirs, single band dipoles, etc. greatly attenuate out of band signals.  And from Joe's data look what a difference 10-20 db can make.  This might be a good case against 80/40  fan dipoles and trap tribanders.
>>> Rick  K2XT 		 	   		
>>>