K2 BFO Tune Up

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K2 BFO Tune Up

Dave Anderson, K4SV
Hi All,

Just completed assembling my K2 kit I had on the shelf for 7 years SN 3089.  

After engineering a cap change to get the VCO voltage correct (C72 from 270 to
300pf) it appears to work now.

I went through the tuning OK but wanted to ask if there is a better way to
adjust the BFO so that all of the filters peak on the same frequency?  In
looking at the old emails about tuning the filters only to find that the
Spectrum APP is not available anymore, can someone point me to a procedure that
can aid in this endeavor?

Thanks in advance,
 
Dave Anderson, K4SV
Tryon, NC
 828 777-5088
 
www.K4SV.com
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Re: K2 BFO Tune Up

Don Wilhelm-4
  Dave,

Go to my website www.w3fpr.com, and look at the article dealing with K2
Dial Calibration - it includes the filter setting, but you may as well
do the whole thing and have good dial calibration as well.
Spectrogram is available for download at Tom Hammond's website
www.n0ss.net, and Tom has some nice documentation with setup information
and screenshots.

You can expect as much as 20 Hz variation in pitch as you change from
filter to filter since it is limited by the DAC resolution.  That is not
enough variation to be troublesome, but is disconcerting the first time
you hear it.  If you have more than 20 Hz, the BFOs are not set up right.

I hope you are not iced in there today, we have a nice slick sheet here
in Wake Forest.

73,
Don W3FPR

On 1/11/2011 2:34 PM, Dave Anderson, K4SV wrote:

> Hi All,
>
> Just completed assembling my K2 kit I had on the shelf for 7 years SN 3089.
>
> After engineering a cap change to get the VCO voltage correct (C72 from 270 to
> 300pf) it appears to work now.
>
> I went through the tuning OK but wanted to ask if there is a better way to
> adjust the BFO so that all of the filters peak on the same frequency?  In
> looking at the old emails about tuning the filters only to find that the
> Spectrum APP is not available anymore, can someone point me to a procedure that
> can aid in this endeavor?
>
> Thanks in advance,
>
> Dave Anderson, K4SV
> Tryon, NC
>   828 777-5088
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html