[Elecraft] I can hear stations on other side of Zero beat

[Don Wilhelm]

Chris,

There are 2 things 'wrong' which are contributing to your problem.
First, the varactors that have shipped recently have a greater 
capacitance range than they used to - same type number, so 'go figure'.
The result is that the filter widths at the wider settings are 
substantially wider than indicated by the K2 display - so the 
recommended FL1 setting of 1.50 kHz may actually be as wide as 2.00 
kHz.  The filters less than 1.00 width seem to be running about normal.
The second thing 'wrong' is a result of the first - the BFO settings in 
the manual are no longer correct due to this change in the varactor 
performance.

The cure is to use Spectrogram to set your filters.  Make sure you set 
the wide CW filter off to one side of zero frequency on the Spectrogram 
screen.  Spectrogram will allow you to measure the actual width of your 
filters.
Take a look at the K2 Dila Calibration article on my website 
www.w3fpr.com for information about using Spectrogram (part 3 is about 
setting the filters).  The application is available for download from 
Tom Hammond's website www.n0ss.net.

You will find a similar problem with the SSB filter set - the width is 
much wider than indicated by the K2.  Spectrogram will give you the tool 
to visually see this and make the proper adjustment.

73,
Don W3FPR

g0kla wrote:
> Hi all,
>
> I just finished building my K2 and it seems to be working well on receive. 
> However, I have noticed that I can hear CW stations on both sides of zero
> beat when using the widest (1.5kHz) filter setting.  It's not just a weakly
> audible signal for very strong 59+20 signals, which I would expect.  I can
> hear a 59 signal at S7 or S8. 
>
> With the 0.7kHz signal this is not the case, so I presume it is to do with
> the way that I have setup the filter and the BFO.  What have I done wrong? 
> Any ideas?  I set it up as per the instructions in the manual.
>
> Chris
> ac2cz
> g0kla
>