K2 - KAF2 Question

classic Classic list List threaded Threaded
2 messages Options
Reply | Threaded
Open this post in threaded view
|

K2 - KAF2 Question

Clark Macaulay KE4RQ
I finally got around to using Spectrogram to align the filters of my 8 month old K2 and completed the final checks for the KSB2 and KAF2.  When using the birdie at 7.000 mhz and selecting either AF1 or AF2, the volume of the birdie increases greatly and sounds almost distorted.  Same with received signals so that when switching between no audio filter and AF2, I have to decrease the AF control.
   
  I searched the archives for a similar question and could find none.  In the instructions, I read "the RF signal should be clear, distinct, and slightly louder when AF2 is selected."  Slighly louder than what: AF1?  In my case, it's a little less than AF1 but a whole lot louder than in the OFF position.  
   
  Do I have it aligned incorrectly?  Adjusting R1 and R2 for a maximum seems so simple I don't see how to mess it up!
   
  Right now, due to the huge change in received signal level when switching in the filter, I'm not using it but sure would like to !  Anybody else see this problem?
   
  73 de Clark ke4rq
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
Reply | Threaded
Open this post in threaded view
|

Re: K2 - KAF2 Question

Don Wilhelm-4
Clark,

When aligning anything with Spectrogram, try to use broadband noise as
the input rather than a single signal - the result will be better.

To easily align the KAF2 with Spectrogram, use an IF filter about 700 Hz
wide, turn on AF2 and align *both* pots to achieve the greatest peak
seen on the Spectrogram display.  Of course that peak should be at your
preferred CW pitch.

You can do the alignment by tuning the 7000 kHz birdie to your chosen
sidetone pitch and then adjusting for the greatest increase in signal
too, but the results using broadband noise are more apparent and you can
see the filter shape at the same time.

73,
Don W3FPR

Clark Macaulay wrote:

> I finally got around to using Spectrogram to align the filters of my 8 month old K2 and completed the final checks for the KSB2 and KAF2.  When using the birdie at 7.000 mhz and selecting either AF1 or AF2, the volume of the birdie increases greatly and sounds almost distorted.  Same with received signals so that when switching between no audio filter and AF2, I have to decrease the AF control.
>    
>   I searched the archives for a similar question and could find none.  In the instructions, I read "the RF signal should be clear, distinct, and slightly louder when AF2 is selected."  Slighly louder than what: AF1?  In my case, it's a little less than AF1 but a whole lot louder than in the OFF position.  
>    
>   Do I have it aligned incorrectly?  Adjusting R1 and R2 for a maximum seems so simple I don't see how to mess it up!
>    
>   Right now, due to the huge change in received signal level when switching in the filter, I'm not using it but sure would like to !  Anybody else see this problem?
>    
>
>  
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com