K2 Receive Issue

[Bernie KF0QS]

Dear Folks:

I have a newly built K2 (#6922).  It works great, but now (after setting
the filters using Spectrogram) I am having a bit of a problem.  In order to
understand the problem, I need to describe how I am hearing things on the
receiver.

On CW, I hear a carrier from the other station (i.e., strong carrier but
zero beat with my BFO), with the tone of the received signal very loud and
strong on one side of the carrier, and quite weak and soft on the other
side.  My problem is that, when I try and contact someone, it looks like
they are hearing me on the frequency that is identical with the weak and
soft side, as opposed to the loud and strong side.  I called CQ twice
recently, got responses both times, but the responding station's signal is
on the weak and soft side.  I would say that the peak received signal is
slightly over 1 khz lower than the transmitted signal.  Obviously, this
creates a problem for when I try to make a contact.  Certainly, it almost
completely eliminates my ability to use the filters unless I use RIT or XIT
to get the rcvr and the xmtr to separate frequencies.

Both RIT and XIT are off when this happens.  I am not using split
VFO's.  Did I screw something up when I set the filters?  I didn't seem to
have this problem before I reset them.  If I did, how would I get back to
the old level of performance?  I suppose I can just reset them to the
values in the manual?

Thanks for any help you can give me.

73 de Bernie, KF0QS

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[Don Wilhelm-4]

Bernie,

That is normally the result of having one or more of the CW filters
aligned to the wrong sideband.  A 1 kHz difference tells me you have
chosen a sidetone pitch of 500 Hz.
Yes, go back to the default values in the manual first, and then
re-align your CW filters from there - do not move the filters very far
from those defaults.

Compare the CW frequencies (and DAC values) with those for CWr - the
ones for CW should have frequencies below 4913 kHz (DAC values either
below 100 or in the low 100s range) while the CWr frequencies will be
above 4913 kHz with DAC values in the high 100s or even above 200.

When aligning the wide CW filter with Spectrogram, be certain the low
frequency side of the passband goes down close to the noise floor before
reaching zero frequency.

73,
Don W3FPR

On 1/7/2012 12:48 AM, Bernie & Cheryl wrote:

> Dear Folks:
>
> I have a newly built K2 (#6922).  It works great, but now (after setting
> the filters using Spectrogram) I am having a bit of a problem.  In order to
> understand the problem, I need to describe how I am hearing things on the
> receiver.
>
> On CW, I hear a carrier from the other station (i.e., strong carrier but
> zero beat with my BFO), with the tone of the received signal very loud and
> strong on one side of the carrier, and quite weak and soft on the other
> side.  My problem is that, when I try and contact someone, it looks like
> they are hearing me on the frequency that is identical with the weak and
> soft side, as opposed to the loud and strong side.  I called CQ twice
> recently, got responses both times, but the responding station's signal is
> on the weak and soft side.  I would say that the peak received signal is
> slightly over 1 khz lower than the transmitted signal.  Obviously, this
> creates a problem for when I try to make a contact.  Certainly, it almost
> completely eliminates my ability to use the filters unless I use RIT or XIT
> to get the rcvr and the xmtr to separate frequencies.
>
> Both RIT and XIT are off when this happens.  I am not using split
> VFO's.  Did I screw something up when I set the filters?  I didn't seem to
> have this problem before I reset them.  If I did, how would I get back to
> the old level of performance?  I suppose I can just reset them to the
> values in the manual?
>
> Thanks for any help you can give me.
>
> 73 de Bernie, KF0QS
>
> ______________________________________________________________
> 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
>

______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
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Please help support this email list: http://www.qsl.net/donate.html