[K2] Aligning my K2/100 - things I learnt...

Posted by VK7JB on Nov 05, 2010; 11:20pm
URL: http://elecraft.85.s1.nabble.com/K2-Question-about-tuning-K2-for-SSB-tp5703977p5710911.html

Thanks to everyone for your tips.  I had a lot of helpful advice, on and off the reflector, and all is sorted out and understood now.  

FWIW, I re-calibrated the 4MHz reference oscillator using the N6KR method and my frequency display is now only 10hz off WWV.  I'm very happy with that.  This is about the 3rd or 4th pass using this method. On the final pass,  I noticed 2 things about my K2 and taking them into account helped reduce the error:   firstly, the spot tone of my K2, set for 600hz, is actually 610hz, not 600hz.   Secondly, when entering CAL FCTR mode after zero beating WWV on sideband,  the beat tone drops  10hz.  I found reference to this in another posting, but somehow missed it the first few times around.  It's easy to account for once you notice it.  There is some drift (+/-40hz or so) as the K2/100 heats up after long overs @100W, but that is easily compensated for while I'm operating, now that I know how (thanks Tom!).

The sideband filters  are now well tuned and the audio reports are good - no longer "muffled".  Adjusting OP1 was easy in the end.  I found that very small changes in frequency, just 25-50hz, make a  big difference to the sound of the transmitted audio. I had to listen carefully and experiment to get the audio profile I wanted.  Adjusting the OP1 SSB filter for optimum transmit audio made the received audio a little "sharp" for my taste, so I did as has been suggested elsewhere and set FL2 to OP1 and adjusted the audio passband of that filter to accentuate the lows and reduce some of the highs.  I keep FL2 in on receive and now I have great audio on both RX and TX.

Thanks again for everyones' input.  I would never have completed this project without the support and collective know-how of this group.  The K2/100 is sitting on my dest here, but I still can't really believe I've done it.

73,

John
VK7JB