[Elecraft] [K3] The Way We Rank Receivers (long)

[brian]

There is another frontier.  That is noise/RFI reduction.
The Pandora's box of RFI has been opened and can't be shut at this point.

We need to address the issue of noise reduction and noise blanketing in 
some quantitative way to compare various RX's.  Right now the 
"comparisons" are all innuendo, e.g. "my old xyz rig did a much better 
job at noise blanketing power line noise than my new widget."  The 
recent QST article on the K3S singing the praises (without giving any 
data) of its NR and NB capability is another example.

This would be tough since the world of RFI sources is huge.  It would 
take some real effort to quantify the world of noise sources and their 
signatures and then find some algorithms to deal with them.  Impossible? 
The world of big data isn't so big any more. Such an catalog might be 
doable.  Algorithms are another issue.  My hope is that NR/NB could be 
made adaptive to recognize the signature(s) and generate appropriate 
algorithms on the fly.

There are a lot of smart people out there who could perhaps address 
these issues.  Unfortunately commercial interests have to see some 
payoff.  They haven't as of yet.  The fact that AM broadcasters are 
being burned by RFI and becoming proactive is a plus.

73 de Brian/K3KO

On 10/25/2016 14:32 PM, Bill Frantz wrote:
> Before I bought my K3, I discussed the radio with someone in the booth
> at Radiofest, a small hamfest held near Monterey, CA. After I had
> learned a very little bit about the radio, I had my wife (KI6SLX), a
> retired QA engineer for Apple, discuss UI issues. When she said it
> seemed OK, I wrote a check.
>
> I like Brian's idea of simulating contest conditions to test receivers.
> Such a simulation would need to be reproducible and good enough that it
> can't be gamed. For testing CW reception, perhaps a fixed set of signals
> modulated through a very linear SSB modulator would work. That could
> give at least 2KHz of signals for the receiver to handle.
>
> The West Valley Amateur Radio Association field day operation sometimes
> has 3 signals active on one band (CW, digital, and SSB). We manage to
> get by running QRP with K3(S)s, KX3s, K2s and carefully placed antennas.
> For CQP, we managed to run two stations on a band at 100 watts with
> similar equipment and techniques.
>
> 73 Bill AE6JV
>
> On 10/25/16 at 5:45 AM, alsopb at comcast.net (brian) wrote:
>
>> I want to know how well a receiver is able to separate a weak signal
>> from strong signals 50-100 Hz away. It would be interesting to
>> speculate how such a measurement would be done. Let the RX use
>> whatever analog or digital tricks it can to achieve the above.
>>
>> Your idea of simulating a contest with a hundreds of signal injected
>> at various random frequencies to gauge RX performance has merit.
>>
>> Have you overlooked the MM, FD and DXpedition RX uses which in fact
>> push the dynamic range and mixing limits today?  There are MM stations
>> which operate two transmitters on the same band.
>
> ---------------------------------------------------------------------------
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