[Elecraft] [K3] Slightly rough CW note on rx

[Randy Moore]

Don,

Thanks.  But my K3 came with the synthesizer stiffener.  If this were 
the problem, wouldn't the roughness be worse at higher audio gain 
settings?  It's not, and appears at the lowest gain that I can copy the 
signal.

73,
Randy, KS4L

On 12/27/2010 4:14 PM, Don Wilhelm wrote:
>  Randy,
>
> Since the problem seems to be confined to times that the internal 
> speaker is being used, I must ask if you have the synthesizer 
> stiffener added to your K3.
>
> Why it would suddenly become a problem when it was not before is 
> anyone's guess, maybe the screws mounting the synthesizer board work a 
> bit loose.
>
> If you do not have the synthesizer stiffener and you use the internal 
> speaker, you should add it promptly.
>
> 73,
> Don W3FPR
>
> On 12/27/2010 4:59 PM, Randy Moore wrote:
>> What's happened to my K3?  I've been noticing today that on rx, the CW
>> note of signals is slightly rough.  It sounds just a little "fuzzy."  If
>> I change modes to USB (no other changes), that roughness goes away
>> entirely.  This is not the mechanical "fuzziness" that I've heard before
>> that's audio frequency dependent.  It happens independent of the tone
>> frequency of the signal, though it seems more apparent at the lower
>> audio frequencies (I have my sidetone pitch set to 450).
>>
>> I have SPKR+PH setup on PF2, so I can turn it on and off quickly.
>> Listening just to the K3 internal speaker, this roughness is always
>> present.  If I listen through my CM-500 headset, and toggle SPKR+PH from
>> YES to NO, the roughness remains on the signal for maybe a second, then
>> goes away.  This must be a clue!
>>
>> This is K3 # 4564 (MCU 4.22, DSP 2.70) and I've been very happy with the
>> CW tone until today.  I'm not aware that I've changed any settings
>> lately.  I don't have NB or NR on.  Just AGC-F (though it is independent
>> of AGC setting).  It is independent of bandwidth.  I have the 2.7kHz and
>> 400Hz filters, and it happens with either and any setting of the DSB
>> bandwidth.
>>
>> 73,
>> Randy, KS4L
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>