Elecraft

BFO on wrong sideband?

Classic

List

Threaded

6 messages Options

TJ Campie

BFO on wrong sideband?

I just got my K2 used and I went through and adjusted the CW filters
because I like mine lower than the previous owner but i have a
feeling I botched it up - I'm zero beat to the ARRL at 14.046.84, and
they transmit on 14.047.5 MHz. I also tried re-aligning the VFO
based on a zero beat on WWWV so I'm not sure where I'm wrong. Please
help!

Tom W0EA
______________________________________________________________
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: BFO on wrong sideband?

Tom,

Go to my website www.w3fpr.com and study the article on K2 Dial
Calibration. Part 3 of that article deals with setting the K2 filters.
If you are not familiar with the use of Spectrogram for setting the K2
filters, I strongly suggest that you become familiar with it. Once you
have used Spectrogram for that task once, doing it a second time is like
"falling off a log". Your K2 performance will be much better for the
effort, and your ears will thank you.

Yes, it is easy to get the BFOs on the wrong sideband by accident. Tune
to a band below 15 meters when setting the filters - 40 meters is
recommended for consistency, but others will do. There is a sideband
reversal that takes place at 15 meters and higher, and using those bands
for setting the filters will only cause confusion and the resulting
frustrations that accompany such confusion.
To prevent having the BFO on the wrong sideband, remember that the CW
filter BFO frequencies (and/or DAC values) must be lower than the CWr
BFO frequencies. Normal CW BFOs will have a frequency in the 4912.8 to
4913.5 kHz range while the CWr BFO frequencies will be in the 4914.2 to
4915.5 kHz range.

Likewise, the SSB USB BFO frequencies will be higher than LSB and the
RTTYr BFOs will be higher than the RTTY BFOs.

Do these things in order.
1) Set the 4 MHz oscillator - use Wayne Burdick's (N6KR) method and view
the 500 and 600 Hz tones transmitted by WWV on the Spectrogram display
to be certain you have tuned WWV correctly (the K2 should be in LSB or
USB mode). Then enter the menu for CAL FCTR and alternate the internal
counter probe between TP2 and TP1 while adjusting C22 - you are looking
for the point where the lower order digits on the display are the same
at both points. The frequency at TP1 moves about 5 times faster than at
TP2, so when doing the adjustment of C22, put the probe in TP1 - it is
just easier that way.
2) Run CAL PLL (remember to put the probe in TP1 and the band to 40 meters).
3) Now put a noise source on the K2 antenna input and adjust the BFO
frequencies (CAL FIL) to place the filter passband at the desired
frequency on the Spectrogram display. Do that for *all* BFOs. If the
passband position is already correct, move it up a notch and then back
to the original - that will tell the K2 that the BFO has been changed
and it will write new EEPROM values based on the new 4 MHz oscillator
frequency, and that is exactly what you want to accomplish.

When you are done, check the tuning of WWV - it should be within 20 Hz
which is the DAC limit or the K2 (look at the tones transmitted by WWV
to verify)

73,
Don W3FPR

Tom Campie wrote:

> I just got my K2 used and I went through and adjusted the CW filters
> because I like mine lower than the previous owner but i have a
> feeling I botched it up - I'm zero beat to the ARRL at 14.046.84, and
> they transmit on 14.047.5 MHz. I also tried re-aligning the VFO
> based on a zero beat on WWWV so I'm not sure where I'm wrong. Please
> help!
>
> Tom W0EA
>
>

TJ Campie

Re: BFO on wrong sideband?

That did it Don! I did in fact have the CW filters on the wrong side
of the band...should have looked in the manual to see where the
frequencies were supposed to be. I think I'm within about 5 to 10 Hz
of WWV and the ARRL practice is coming in right on my sidetone freq.
Now its time for some major contacts!

Thanks for the help. 73

Tom W0EA

On Jul 17, 2009, at 10:13 PM, Don Wilhelm wrote:

> Tom,
>
> Go to my website www.w3fpr.com and study the article on K2 Dial
> Calibration. Part 3 of that article deals with setting the K2
> filters. If you are not familiar with the use of Spectrogram for
> setting the K2 filters, I strongly suggest that you become familiar
> with it. Once you have used Spectrogram for that task once, doing
> it a second time is like "falling off a log". Your K2 performance
> will be much better for the effort, and your ears will thank you.
>
> Yes, it is easy to get the BFOs on the wrong sideband by accident.
> Tune to a band below 15 meters when setting the filters - 40 meters
> is recommended for consistency, but others will do. There is a
> sideband reversal that takes place at 15 meters and higher, and
> using those bands for setting the filters will only cause confusion
> and the resulting frustrations that accompany such confusion.
> To prevent having the BFO on the wrong sideband, remember that the
> CW filter BFO frequencies (and/or DAC values) must be lower than the
> CWr BFO frequencies. Normal CW BFOs will have a frequency in the
> 4912.8 to 4913.5 kHz range while the CWr BFO frequencies will be in
> the 4914.2 to 4915.5 kHz range.
>
> Likewise, the SSB USB BFO frequencies will be higher than LSB and
> the RTTYr BFOs will be higher than the RTTY BFOs.
>
> Do these things in order.
> 1) Set the 4 MHz oscillator - use Wayne Burdick's (N6KR) method and
> view the 500 and 600 Hz tones transmitted by WWV on the Spectrogram
> display to be certain you have tuned WWV correctly (the K2 should be
> in LSB or USB mode). Then enter the menu for CAL FCTR and
> alternate the internal counter probe between TP2 and TP1 while
> adjusting C22 - you are looking for the point where the lower order
> digits on the display are the same at both points. The frequency at
> TP1 moves about 5 times faster than at TP2, so when doing the
> adjustment of C22, put the probe in TP1 - it is just easier that way.
> 2) Run CAL PLL (remember to put the probe in TP1 and the band to 40
> meters).
> 3) Now put a noise source on the K2 antenna input and adjust the BFO
> frequencies (CAL FIL) to place the filter passband at the desired
> frequency on the Spectrogram display. Do that for *all* BFOs. If
> the passband position is already correct, move it up a notch and
> then back to the original - that will tell the K2 that the BFO has
> been changed and it will write new EEPROM values based on the new 4
> MHz oscillator frequency, and that is exactly what you want to
> accomplish.
>
> When you are done, check the tuning of WWV - it should be within 20
> Hz which is the DAC limit or the K2 (look at the tones transmitted
> by WWV to verify)
>
> 73,
> Don W3FPR
>
> Tom Campie wrote:
>> I just got my K2 used and I went through and adjusted the CW
>> filters because I like mine lower than the previous owner but i
>> have a feeling I botched it up - I'm zero beat to the ARRL at
>> 14.046.84, and they transmit on 14.047.5 MHz. I also tried re-
>> aligning the VFO based on a zero beat on WWWV so I'm not sure
>> where I'm wrong. Please help!
>>
>> Tom W0EA
>>

Don Wilhelm-4

Re: BFO on wrong sideband?

Tom,

That is great. Now enjoy that K2.

73,
Don W3FPR

Tom Campie wrote:

> That did it Don! I did in fact have the CW filters on the wrong side
> of the band...should have looked in the manual to see where the
> frequencies were supposed to be. I think I'm within about 5 to 10 Hz
> of WWV and the ARRL practice is coming in right on my sidetone freq.
> Now its time for some major contacts!
>
> Thanks for the help. 73
>
> Tom W0EA
>
>

AD4C2009

Re: BFO on wrong sideband?

In reply to this post by TJ Campie

The web site provided is not active,my IE did not find it,could anyone tell what's the correct address? I am very interested to see it,thanks

AD4C

"The difference between genius and stupidity is that genius has its limits".. -- Albert Einstein

--- On Sat, 7/18/09, Tom Campie <[hidden email]> wrote:

From: Tom Campie [hidden email]

On Jul 17, 2009, at 10:13 PM, Don Wilhelm wrote:

______________________________________________________________
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

______________________________________________________________
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

g3ymc

Re: BFO on wrong sideband?

On 18 Jul 2009 at 4:10, Hector Padron wrote:

> The web site provided is not active,my IE did not find it,could anyone
> tell what's the correct address? I am very interested to see it,thanks
> AD4C

http://www.w3fpr.com/ works fine here (nice site...).

73 Dave G3YMC

http://www.davesergeant.com

______________________________________________________________
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