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k2 receiver shift problem fixed, now tx shift problem

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iz0fyl

k2 receiver shift problem fixed, now tx shift problem

hi friends
my last message was blank because I sent it via web!
as tom and don suggested I re-calibrated all filters with the cal fil option and the receiver shift now is fixed.
unfortunally I found a minor problem in tx mode: my tx frequency is around 0.6 khz up.
so I'm serching help again. hihi
any suggest?
thanks
luca
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Don Wilhelm-4

Re: k2 receiver shift problem fixed, now tx shift problem

Luca,

Check to be certain your sidetone pitch is set to the same frequency as
you set the center of the CW filters.
After checking that, go back to the Filter alignment and check the BFO
frequencies while on a band no higher than 17 meters - The BFO frequency
for CW should be lower than that for CWrev. The symptom you describe
often occurs when you have the filter on the wrong sideband.

Bottom line - all CW BFO frequencies should be around 4913.xx kHz and
the CW rev BFO frequencies should all be in the vicinity of 4914.xx if
your crystal set is typical - Since CW FL1 is usually a wide filter, the
BFO frequency for CW Rev FL1 may be higher than I mentioned by a kHz or so.

luca amendola wrote:

> hi friends
> my last message was blank because I sent it via web!
> as tom and don suggested I re-calibrated all filters with the cal fil option and the receiver shift now is fixed.
> unfortunally I found a minor problem in tx mode: my tx frequency is around 0.6 khz up.
> so I'm serching help again. hihi
> any suggest?
> thanks
> luca
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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iz0fyl

Re: k2 receiver shift problem fixed, now tx shift problem

Don
thanks for your quick reply.
May be I did'nt get something.
To avoid mistakes, I adjusted the sidetone pitch to 600hz than I applied
exactly the manual procedure setting the suggested filter bandwiths and bfo
values. Actuallly the receiver frequency is fine centered for all filters.
If the manual suggested values don't work well in tx mode, which is the
right value to apply?
And, if I change again the bfo values, does the rx freq shift again?
luca

luca
----- Original Message -----
From: "Don Wilhelm" <[hidden email]>
To: "luca amendola" <[hidden email]>
Cc: <[hidden email]>
Sent: Monday, August 17, 2009 2:51 AM
Subject: Re: [Elecraft] k2 receiver shift problem fixed, now tx shift
problem

> Luca,
>
> Check to be certain your sidetone pitch is set to the same frequency as
> you set the center of the CW filters.
> After checking that, go back to the Filter alignment and check the BFO
> frequencies while on a band no higher than 17 meters - The BFO frequency
> for CW should be lower than that for CWrev. The symptom you describe
> often occurs when you have the filter on the wrong sideband.
>
> Bottom line - all CW BFO frequencies should be around 4913.xx kHz and the
> CW rev BFO frequencies should all be in the vicinity of 4914.xx if your
> crystal set is typical - Since CW FL1 is usually a wide filter, the BFO
> frequency for CW Rev FL1 may be higher than I mentioned by a kHz or so.
>
> luca amendola wrote:
>> hi friends
>> my last message was blank because I sent it via web!
>> as tom and don suggested I re-calibrated all filters with the cal fil
>> option and the receiver shift now is fixed.
>> unfortunally I found a minor problem in tx mode: my tx frequency is
>> around 0.6 khz up.
>> so I'm serching help again. hihi
>> any suggest?
>> thanks luca
>> ______________________________________________________________
>> 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
>> ------------------------------------------------------------------------
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com Version: 8.5.392 / Virus Database:
>> 270.13.58/2306 - Release Date: 08/16/09 06:09:00
>>
>>

Don Wilhelm-4

Re: k2 receiver shift problem fixed, now tx shift problem

Luca,

The transmit offset should work correctly - it is automatic in the K2,
the offset is computed by the firmware. To be off by the amount of the
sidetone is unusual. The usual situation is when the transmit frequency
error is two times the sidetone pitch, and that is caused by having the
passband on the wrong sideband.

How are you determining that the transmit frequency is shifted? The K2
displays the carrier frequency, and some others may display the tone
frequency. If you are measuring the K2 output with another receiver,
that is something to be concerned about because you may not be able to
depend depend on the dial reading of the other receiver.

If you have not calibrated your K2 dial (see the K2 Dial Calibration
article on my website www.w3fpr.com), then you cannot depend on the K2
dial reading either.

To check the transmit frequency using another receiver, use the
following method - which ignores the precise dial reading on both the K2
and the other receiver by matching two signals..
1) Tune the signal source on the K2 so the pitch matches your 600 Hz
sidetone pitch.
2) Tune the same source on the other receiver.
3) Now use the K2 to transmit into a dummy load - the other receiver
should hear the K2 at the same frequency and pitch as the signal source
was heard on that receiver.

73,
Don W3FPR

uniroma wrote:

> Don
> thanks for your quick reply.
> May be I did'nt get something.
> To avoid mistakes, I adjusted the sidetone pitch to 600hz than I applied
> exactly the manual procedure setting the suggested filter bandwiths and bfo
> values. Actuallly the receiver frequency is fine centered for all filters.
> If the manual suggested values don't work well in tx mode, which is the
> right value to apply?
> And, if I change again the bfo values, does the rx freq shift again?
> luca
>
>

iz0fyl

Re: k2 receiver shift problem fixed, now tx shift problem

In reply to this post by iz0fyl

Hi
Don the problem was again in the bfo.
I re-did again cal fil using the tom's procedure.
I tuned bfos with the graph spectrum.
Finally the bfo is shifted exatly of 1.2 khz.
the same values of cw nor bfo applied to cw rec cal , produce a perfect
centered filters in cw rev!
what does it mean?
luca
----- Original Message -----
From: "luca amendola" <[hidden email]>
To: <[hidden email]>
Sent: Monday, August 17, 2009 1:19 AM
Subject: [Elecraft] k2 receiver shift problem fixed, now tx shift problem

> hi friends
> my last message was blank because I sent it via web!
> as tom and don suggested I re-calibrated all filters with the cal fil
> option and the receiver shift now is fixed.
> unfortunally I found a minor problem in tx mode: my tx frequency is around
> 0.6 khz up.
> so I'm serching help again. hihi
> any suggest?
> thanks
> luca
> ______________________________________________________________
> 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

iz0fyl

Re: k2 receiver shift problem fixed, now tx shift problem

In reply to this post by iz0fyl

> Hi
> Don the problem was again in the bfo.
> I re-did again cal fil using the tom's procedure.
> I tuned bfos with the graph spectrum.
> Finally the bfo is shifted exatly of 1.2 khz.
> the same values of cw nor bfo applied to cw rec cal , produce a perfect
> centered filters in cw rev!
> what does it mean?
> luca
> ----- Original Message -----
> From: "luca amendola" <[hidden email]>
> To: <[hidden email]>
> Sent: Monday, August 17, 2009 1:19 AM
> Subject: [Elecraft] k2 receiver shift problem fixed, now tx shift problem
>
>
>> hi friends
>> my last message was blank because I sent it via web!
>> as tom and don suggested I re-calibrated all filters with the cal fil
>> option and the receiver shift now is fixed.
>> unfortunally I found a minor problem in tx mode: my tx frequency is
>> around 0.6 khz up.
>> so I'm serching help again. hihi
>> any suggest?
>> thanks
>> luca
>> ______________________________________________________________
>> 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
>

Don Wilhelm-4

Re: k2 receiver shift problem fixed, now tx shift problem

In reply to this post by iz0fyl

Luca,

1.2 kHz off means that you have one or more of the CW filters set on the
wrong sideband.

The CW BFO frequencies should all be in the range of 4913.xx kHz.
The CW r BFO frequencies should all be higher than 4914 kHz.

Go to CAL FIL and tap BAND- to display the DAC value for the selected
BFO. Use FL2 first with a width set near 0.70.
Now, use Spectrogram (or Spectran or other FFT audio spectrum analyzer)
and move the VFO knob to center the filter passband at 600 Hz. Move the
passband around and you will see that there are two points where the
passband will center at 600 Hz. For CW use the setting with the lower
DAC value and for CWr, use the setting with the higher DAC value.

Do that for all the CW and CWr filters FL2 through FL4.

Now do FL1 - If you have FL1 set to a width that is greater than 2 times
your sidetone pitch of 600 Hz, then you cannot center the filter and
retain single signal reception. You must position the filter passband
so the left edge of the passband slope is at a low audio frequency, but
make certain the slope can be seen clearly and drops in amplitude at the
left edge. For CW use, it does not matter what low audio frequency the
slope is positioned at, but it does matter that the filter skirt drops
to near the receiver noise level above zero frequency. Again, there are
two DAC values where that can happen - use the lower one for CW and the
higher one for CWr.

If you have followed that, you should transmit on the same frequency you
are receiving.
It is possible that we have a language confusion problem at work here
too. If I have not been clear enough, please send me an email and I
will try to help more. Sorry that I am unable to communicate in your
native language.

73,
Don W3FPR

luca amendola wrote: