[Elecraft] K3 to IC-7800 Comparison?

[Wes (N7WS)]

I was responding to the comment that you "thoughtfully" deleted so you could go 
on with your critique.

I know it's hard for some people to believe, but some of us in the unwashed 
masses are actually capable of deciding what is "useful" to us in our own 
situations.
.

On 9/15/2015 9:50 AM, Jim Brown wrote:
> On Tue,9/15/2015 7:10 AM, Wes (N7WS) wrote:
>> Seems to me that he's just trying to explain himself. 
>
> Yes, but in doing so, he's making it clear that his work does not contribute 
> useful information to a ham trying to evaluate the relative performance of 
> radios in a strong signal environment, AND that's what the measurement is 
> designed to show -- IF the same level of test signal is applied to all of the 
> radios.
>
> For me, primarily a contester, secondarily a DXer, the primary factors in 
> choosing a radio are performance in a strong signal environment, a clean TX 
> signal, and a very efficient user interface. After hearing Adam speak, I had 
> hoped that his work would contribute to that process, but because the level of 
> his excitation varies depending on the shortcomings of the radio, it fails to 
> provide useful information.
>
> To clarify -- the strong signal performance and dynamic range of SDRs is 
> limited by the total voltage at the input to the digital system. If there is 
> no input filtering (i.e., a preselector, bandpass filter, or hardware 
> attenuator), the digital system sees the broadband spectrum from whatever 
> antenna drives it. That's everything from DC to daylight -- AM broadcast, all 
> the other ham bands, shortwave broadcast, all other users of the spectrum. It 
> is the SUM of all of those signals that combine to overload the digital 
> system. When that combined signal level hits digital clip (all bits are 
> digital zero), the radio stops working.
>
> It is, of course, possible for the user to add bandpass filters outboard to 
> the radio, and many contesters with SO2R and multi-transmitter stations do so. 
> This would, indeed, significantly reduce the input to the digital system to 
> inband signals. BUT -- SO2R and multi-transmitter stations with closely spaced 
> antennas could still overload the digital system even with that filtering.
>
> And there's still in-band QRM to get you to digital clip -- a ham a block or 
> two away running power amp, or a mile away with his antenna pointed at you, 
> and the sum of all the in-band signals during a major contest. In EU and AS, 
> there are big broadcast signals in parts of the 40M band that are going to 
> sail right through the world's best preselector or bandpass filter without 
> attenuation.
>
> My neighbor W6DRX (0.3 miles from me and an active contester) and I both 
> bought K3s as soon as the radio was announced because we realized that it was 
> the only way we could coexist and remain friends. :)
>
> 73, Jim K9YC
> ______________________________________________________________