K3 receiver noise questionable test results

[Don Wilhelm-4]

James,

In the situation you describe, only a low pass audio filter would help -
it should be available soon.
Perhaps some others are hearing the same thing, but have not described
it as well.

I have also heard from K3 owners who have changed their AGC parameters
closer to the SLP = 002 and TH = 002 that I normally use and have
reported a big change in the apparent noise of their K3.  There is not
one answer for everyone - it all depends on the noise source.

73,
Don W3FPR

James Sarte wrote:

> Greetings Al et all,
>
> In my case, I experience a significant amount of high-frequency white noise.
> I'm not sure if that's the best way to describe it.  Think of the
> high-pitched whine you'd hear if you're travelling inside an airplane.
> Adjusting AGC, gain, and even RX EQ settings don't have much of an effect.
> If anything, adjusting AGC and gain controls just seem to reduce volume but
> not actual audio characteristic.
>
> 73 de James K2QI
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Al Lorona
> Sent: Friday, December 18, 2009 9:07 PM
> To: [hidden email]
> Subject: Re: [Elecraft] K3 receiver noise questionable test results
>
> <snip>
>
> Help me out here: are we talking about the *amount* of noise, or the
> *character* of the noise? I don't even think we've established the answer to
> this.
>
> If it's the amount of noise that folks are hearing, wouldn't you just turn
> the gain down to match your Other receiver? No two receivers have the same
> amount of gain, and I think this point has been lost on some of us.
>
> If it's the character of the noise, and if you find it objectionable, and if
> no settings of gain, filtering or noise reduction change it, I'd say
> it's time to go back to the Other receiver, and I'm not being facetious
> about this.
>
> <snip>
>
> Al  W6LX
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.717 / Virus Database: 270.14.114/2575 - Release Date: 12/19/09 03:33:00
>
>  

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

[Julian, G4ILO]

Don Wilhelm-4 wrote

In the situation you describe, only a low pass audio filter would help -
it should be available soon.
Perhaps some others are hearing the same thing, but have not described
it as well.

I'm not convinced, Don.

I'm looking at the output from the K3 using Spectran now. I can see "spurious" signals on the trace in the 10KHz - 14KHz region *when other signals are present*. But the noise floor of the K3 outside the selected passband is actually much lower than other receivers. It's something like 60dB down on the level of noise within the passband going from 3KHz to 20KHz.