[Elecraft] Noisy K-3 Receiver

[Mike Harris]

G'day,

The simple fact is that the faithful will always suggest that the K3 
hears more, is more sensitive or is more transparent to band noise 
etc etc.  Also you have to fiddle with the AGC, PRE, ATT and RF gain 
whereas other radios just sound nicer out of the box.  I don't have 
a problem with fiddling with AGC and equaliser parameters to tailor 
the receive to my liking, but to have to do it to make it sound 
acceptable is another thing altogether.

There is an often referred to AF filter module which installs on the 
main DSP board and apparently cuts out a lot of unnecessary high 
frequency audio.  Sadly though often referred to it just isn't being 
made available despite very positive comment from some of those who 
have field tested it.

The KAF2 filter for the K2 made all the difference in the world to 
listening to SSB.

Regards,

Mike VP8NO

----- Original Message ----- 
From: "Bill W4ZV" <btippett at alum.mit.edu>
To: <elecraft at mailman.qth.net>
Sent: Wednesday, December 16, 2009 9:26 AM
Subject: Re: [Elecraft] Noisy K-3 Receiver


>
>
>>>>Thoughts: I realize that all s-meters read differently and the 
>>>>fact that
> the MP s-meter shows a 4 s-unit stronger signal above the noise 
> level
> doesn't
> mean alot.
>
> Correct, 4 S-units on an MP meter at that level is probably more 
> like 2 real
> S-units (10-12 dB).  See below:
>
> http://www.mail-archive.com/elecraft@mailman.qth.net/msg63910.html
>
>>>>But the fact is that the signal on the MP sounds MUCH louder
> with alot more headroom above the noise level.  The K-3 receiver 
> sounds so
> noisy even with the S-7 signal that it isn't enjoyable listening 
> to and
> that's
> why I ran the comparisons because I couldn't stand all the noise. 
> Switching
> on the K-3's NR, ATT, and/or adjusting the RF Gain does help some 
> but the
> signal still sounds noisy compared to the MP.
>
> CONFIG: AGC THR may be set too high.  Try a lower setting.
>
> Also, for a given band/antenna combination, set ATT ON>ATT OFF>PRE 
> ON in
> that order and stop when connecting the antenna gives you band 
> noise (i.e.
> don't use any more gain than necessary).  This ensures you are not 
> wasting
> dynamic range by setting the noise floor correctly.  After doing 
> this, I set
> my AF GAIN knob to about 9-10 o'clock (for headphones) and adjust 
> RF GAIN
> back for a comfortable volume.  If you run RF GAIN wide open the 
> receiver
> will sound noisy and you are limiting your dynamic range.
>
> 73,  Bill