[Elecraft] Noisy K-3 Receiver

[Julian, G4ILO]

RLVZ wrote:
> 
> Hi Guys,
> 
> I'd appreciate your thoughts as to why my K-3 receiver is so noisy.  I'd 
> really like to make this radio perform.  The radio is Serial #603F
> (factory 
> model) running 1.2.10.27.  I purchased the unit from the original owner a 
> couple of months ago so I don't know if it's always been this noisy but I
> do 
> know it was the same before I  recently updated software to 1.2.10.27.  
> The 
> radio is in immaculate condition and was never used mobile or bounced
> around.  
> (it's a beautiful radio that looks like new!)
> 
> I say the receiver is noisy based upon listening to dozens of different 
> signals on: 40/20/15 m. and by doing numerous A/B comparison tests.  The 
> comparison tests were done with the K-3 Pre-Amp turned Off.  (and tried
> with ATT 
> on and off but mostly on to reduce noise).  
> 
> Radio 1: Yaesu FT-1000-MP w/AF Mod.  A signal is peaking S-8 and with the 
> no signal noise level is averaging S-1.  Therefore, the signal is peaking 
> aprx. 7 s-units above the noise based upon the MP s-meter and the signal
> sounds 
> loud and is way above the noise level.  Now I switch to the K-3:
> 
> Radio 2: K-3 tuned to the same signal with PreAmp Off and is peaking S-7 
> but the no signal noise level is noisy S-4 to S-5.  Therefore, the signal
> is 
> peaking only about 2 or 3 s-units above the noise level based upon the K-3 
> s-meter.  The result is that the MP has aprx. a 4 s-unit  S/N ratio
> advantage. 
> 
> 
> 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.  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.  
> 
> Based upon "Reviews" of the K-3 I believe that I must have an unusual "K-3 
> noisy receiver" problem.
> 
> I'd sure appreciate your ideas on how I can get a better S/N ratio on my 
> K-3.       
> 
> Thanks!
> 
> 

Hi Dick.

I wonder if what you are experiencing is simply the result of your K3's S
meter being adjusted to read high on noise, coupled with the fact that its
calibration results in something close to the "standrard" 6dB per S-point?

I would suggest that you perform the S meter calibration procedure described
in the manual.

I am not familiar with the FT-1000MP but with many radios the S meter
basically reads the AGC voltage and it takes a significant signal to shift
it at all after which it shoots up at about 2dB per S point until it reaches
the S9 level.

-----
Julian, G4ILO. K2 #392  K3 #222.
* G4ILO's Shack - http://www.g4ilo.com
* KComm - http://www.g4ilo.com/kcomm.html
* KTune - http://www.g4ilo.com/ktune.html

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