Posted by
dave.wilburn on
Mar 21, 2007; 12:29am
URL: http://elecraft.85.s1.nabble.com/Zero-beat-WWV-tp444945p444947.html
Good stuff Don. Thanks. Yea, the 9999.99, I was not worried about at
all. It is the 1300 Hz I have to wander over to, to get the CW signal
that is bothering me. I am experiencing the same thing with local
signals, I have generated from other radios. I will check out WWV
during the quiet time and see what I find.
As far as "Just adjust the CW BFOs so the passband is centered...", what
are you telling me to do here? I have run through c22 adjustment
(started out at 10000.09 for WWV, and got to 9999.99 using the "Wayne"
method), CAL PLL and CAL FIL (with Spectrogram) at least 3 times.
Should I go back and do the BFO test?
Admittedly, it is possible, even likely, that I am making the same
mistake each time I have run them. I have seen the U and L frequency
readout get better, but not the CW. Additionally, it transmits on the
correct frequency.
David Wilburn
[hidden email]
K4DGW
K2 #5982
Don Wilhelm wrote:
> Dave,
>
> If you have WWV properly tuned at 9999.99 (when in SSB mode), that is
> only 10 Hz off frequency, and is well within the range of error to be
> expected with the K2. The digital quantizing error is about 20 Hz.
>
> The K2 always displays the frequency of the carrier - so when tuned
> properly to WWV, you will hear (or see on Spectrogram) the tones
> demodulated (as you have done), but when switching to CW, you should
> hear the carrier at the pitch you have set for the sidetone.
>
> When listening to WWV in CW mode it is easy to mistake one of the tones
> they transmit for the carrier. At the times they transmit a 600 Hz
> tone, you will be able to hear discrete signals at 9999.40, 10,000.00
> and 10,000.60 since it is an AM signal transmitting a 600 Hz tone. (You
> can hear one signal at the carrier minus the transmitted tone pitch, the
> carrier itself, and another signal at the carrier plus the tone pitch.)
> If the CW filter is narrow enough, you will hear each of these signals
> as separate signals in the receiver - you must be careful to identify
> the actual carrier. Using the wrong one will create a large apparent
> error in your dial readout. It is best to tune WWV during the minutes
> they do not transmit a tone - tune the carrier to your sidetone pitch
> and the dial should read correctly.
>
> Just adjust the CW BFOs so the passband is centered at your chosen
> sidetone pitch (using a noise input, NOT a single signal) - and set the
> dial calibration in LSB or USB, then believe that the K2 will take care
> of the offset for you. On CW, the dial readout will be the carrier
> frequency of the station you are listening to and will also be the
> frequency you will transmit on.
>
> 73,
> Don W3FPR
>
> David Wilburn wrote:
>> I have setup Spectogram, and have 500 & 600 Hz markers setup. I then
>> set the K2 to 10000.00, in U mode, and adjust the frequency until I
>> have either 500 or 600 Hz depending on which minute it is (odd minutes
>> being a 600 Hz tone and even being a 500 Hz tone, even though this
>> seems backwards of how it should be).
>>
>> I then used this zero beat reference, and the procedure on page 101 of
>> the K2 manual so that I have it down to U or L mode is zero beat at
>> 9999.99.
>>
>> I notice the calibration on page 101 of the K2 manual says to use U or
>> L mode. My question, is how much should the offset be when I go to CW
>> mode? I am trying to track down why my CW RX frequency is so far from
>> my USB frequency (was 1500 Hz off at one point). I have it better, but
>> I am sure the issue is with how I did the alignments.
>
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