Zero Beat WWV
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Ok, totally confused by the zero beat to WWV. I can zero beat an un-oscillated WWV carrier at two points, in USS and LSB. When they add the odd-hour 600hz tone, things become even more confusing.
I suppose I am relagated to obtaining a spectrum analyser, but which mode should I use to zero beat when I do so? USB, LSB or CW? Killing me here... KQ4FW - Joe _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Joe,
Let me see if I can help. First I usually think of 'tuning WWV' rather than 'zero-beating' just to keep my mind straight - I leave the Zero Beat term reserved for CW use when you want to tune the desired signal to match your sidetone pitch. Tune WWV in using LSB or USB because the K2 does not add an offset for LSB and USB. There are 3 ways of doing it: 1) Tune the carrier to an audio frequency of zero (which you cannot really hear, but go as low as you can) and refine it by tuning until the voice announcements sound 'natural'. 2) Understand the sequence of tones transmitted by WWV - for the most part they alternate between 500 and 600 Hz on alternate minutes (there is also a 440 Hz tone transmitted one minute of each hour). Set your sidetone pitch to either 500 or 600 Hz and use the SPOT on the K2 to match the transmitted tone at the correct minute. Or 3) My preferred method is to use Spectrogram (yes, this is an audio 'spectrum analyzer') and feed the K2 audio into the computer soundcard input - with Spectrogram set up properly, you will be able to see the transmitted tones on the Spectrogram display, set a marker in Spectrogram to 500 Hz and another to 600 Hz and watch the display to be certain the tones alternate between those two markers - when they do, you are accurately tuned to WWV. I find this is the easiest method for folks like me who have trouble discerning the pitch of a tone - if you are a musician and have 'perfect pitch' you will not likely need such a visual aid. You can download the last freeware version of Spectrogram from Tom Hammond's website www.n0ss.net. If you need some information on how to set up Spectrogram, read over the K2 dial calibration article on my website http://w3fpr.qrpradio.com - the latter part of that article (CAL PLL) has information and links to setting up Spectrogram. 73, Don W3FPR joey mcg wrote: > Ok, totally confused by the zero beat to WWV. I can zero beat an un-oscillated WWV carrier at two points, in USS and LSB. When they add the odd-hour 600hz tone, things become even more confusing. > > I suppose I am relagated to obtaining a spectrum analyser, but which mode should I use to zero beat when I do so? USB, LSB or CW? > > Killing me here... > > KQ4FW - Joe _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by joey mcg
They turn off the tone modulation every hour for a bit. See their schedule
for time of this. That is the time you do your most accurate zero beating, and in CW mode of your receiver. Stuart K5KVH _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by joey mcg
At 05:25 PM 7/5/2007, joey mcg wrote...
>Ok, totally confused by the zero beat to WWV. I can zero beat an >un-oscillated WWV carrier at two points, in USS and LSB. When they >add the odd-hour 600hz tone, things become even more confusing. Bounce back and forth between LSB and USB (hold down CW RV for a second to quickly switch), adjusting the frequency until the tones WWV transmits sound the same in both modes. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by joey mcg
A variation on #1 is to start watching the S meter when you get really
close, with AGC set to fast. The response on the K2 seems to be quick enough that you can see if futter when you get with 10Hz and decide which is closest. If you are lucky it won't flutter and will slowly ramp up and down, all at the difference frequency. 73, Leigh/WA5ZNU On Thu, 5 Jul 2007 5:54 pm, Don Wilhelm wrote: > Joe, > > Let me see if I can help. First I usually think of 'tuning WWV' rather > than 'zero-beating' just to keep my mind straight - I leave the Zero > Beat term reserved for CW use when you want to tune the desired signal > to match your sidetone pitch. > > Tune WWV in using LSB or USB because the K2 does not add an offset for > LSB and USB. There are 3 ways of doing it: 1) Tune the carrier to an > audio frequency of zero (which you cannot really hear, but go as low as > you can) and refine it by tuning until the voice announcements sound > 'natural'. Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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