[Elecraft] Problem with K2 transmit quality

[Don Wilhelm]

Giulio,

As far as the transmit path is concerned, TUNE is exactly the same as CW.
The activation path through the microprocessor is different.

You might try setting the keying input to HAND and using only the dot 
side of the paddles to see if there is some problem with the keying 
algorithms inside the microprocessor chip.

Do you have an older K2 that has not been upgraded.  Check the value of 
RF Board R1 and R2 (near the key jack).  They should be 220 ohms.  
Remove the left side panel to see the resistors easily.

If it does not happen in TUNE as well as CW, it is most likely in the 
keying circuit somewhere - and that is an all digital path until it 
reaches the Control Board U8 (this is a DAC) output for the VPWR signal 
- but then the TUNE also uses this same output.

I wish I could help more, but you are posing a 'mystery' situation.  It 
is possible that you have had a failure of some strange kind inside the 
firmware chip, but that is a rare occurrance.

You could try a Master Reset, but if you do, write down all your menu 
settings including the filter settings because that reset will put them 
all back to the default values.

73,
Don W3FPR

Giulio Pico - IW3HVB wrote:
> Don Wilhelm wrote:
>   
>> Giulio,
>>
>> Do you have anything with a transformer near the K2?  Move the K2 at 
>> least a meter away from anything with a transformer and try it again.
>>
>> If moving it cures the problem, you may either move the device(s) with 
>> transformers or install the VCO Shield Kit in your K2.
>>
>> 73,
>> Don W3FPR
>>     
> That was my idea too, but I have no transformers (switching ps and 
> everything else at 1 mt or more and switched off)  and the VCO shielding 
> is already in place......
>
> Is the tune carrier generated at the same manner of the CW note?
>
> 73 de Giulio IW3HVB
>   
>