[Elecraft] [K1] Building a K1 no side tone

[Rick/WA6ES]

Well Don, I went back checked everything, every hole and every solder fleck.
Cleaned up pad solder joints and just verified all, did I mention I missed a
couple of holes. Plugged in the power and earbuds and I heard noise, tried
the keyer and it was making noise, backwards but dits and dahs. I figure the
world would switch to left handed being normal, maybe next year. 
Anyway now I can say I am off to page 38 and winding that L1. I just have to
remember this is my training for making the K2 later this year. With the K2
I will slow it down a notch and read twice before doing anything.
Thanks Again
Rick/WA6ES


Don Wilhelm-4 wrote:
> 
> Rick,
> 
> The K1 display changes to a simulated bargraph to indicate the power 
> output when keyed.  You will not have any power output at this stage of 
> assembly, so your statement of a 'blank display' may be just fine.  
> Since the backlight stays on during keying, I should retract my 
> statement about a power problem.
> 
> The most likely reason for no sidetone is soldering - check to see if 
> all points are well soldered and none skipped.  You do have the AF Gain 
> advanced do you not?  The K1 sidetone varies with the AF Gain setting.
> The source of the sidetone is the output from the DAC on the Front 
> Panel, U2 pin 1.  If you have an oscilloscope, you could check to see if 
> you have an audio signal there when the K1 is keyed.  Lacking a 'scope, 
> connect a pair of leads to an audio amplifier input (line in of a 
> computer soundcard or an MP3/CD player) and probe at that point to see 
> if there is any sound - it might not sound great, but you will know if 
> the signal is present.
> The signal leaves the front panel via J1 pin 5.  Look at the schematic 
> for the RF Board sheet 1 in the lower left corner and you will see the 
> components that the sidetone signal (XFIL/TONE) are applied to.  It 
> makes it way to the AF Amp through the AF Gain control.  You should hear 
> some 'white noise' sound when the AF Gain is advanced.  If the audio is 
> totally silent, you may have a problem with the AF Amp rather than the 
> sidetone.
> 
> 73,
> Don W3FPR
> 
> 
>>
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