Sidetone or zero beat
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I wrote: > For tone deaf folks, Elecraft offers a CW tuning indicator which may be better for you. Actually I short-changed that feature. Get within ~100 Hz and the K3 automatically zero beats for you. From the FAQ: ##################################################Speaking of CW .. is there a method for spotting? There are two methods. The first is the normal spotting tone that you tune for zero beat. TAP the SPOT switch to toggle the tone on and off. There is also a feature called CWT. You press this button and the right half of the S Meter display becomes a zero-center tuning meter. You tune the signal in according to this bar graph. When you are close (within a hundred Hz or so either way) you can either finish tuning yourself, or TAP the SPOT button and voila -- the K3 will tune itself to zero beat. The same feature works in data modes. This is great for tuning in PSK31 and TTY signals. There's a front-panel knob that controls the volume level of the spotting tone. ############################################### Also here's a fun website to test how well you can match two 500 Hz tones (like you would when zero-beating a 500 Hz CW pitch): http://tonometric.com/adaptivepitch/ 73, Bill W4ZV _______________________________________________ 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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Most modern transceivers, including the Elecraft rigs, have virtually no output within 100 Hz or so of the carrier frequency, thanks to the excellent I.F. filters they use. That makes finding zero beat with the sidetone mandatory to avoid an error or 100 Hz or more in trying to tune onto the other station's frequency. Ron AC7AC ================================== My Drake R4C had good IF filters but I could move the filter over to the carrier frequency with the excellent passband tuning and "see" the beat note on the (analog) S meter. The needle would go from a fast vibration to a slower one with more movement as I approched zero beat. No hearing needed. This was how I set the xtal calibrator to zero beat with WWV. Then , I could read a frequency to the nearest khz, something I could only dream of with older rigs. 73 Rick Dettinger K7MW _______________________________________________ _______________________________________________ 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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I find the K2 and other modern rigs hard to zero, as I have NO tone matching judgment. What I do is jump between cw and cw reverse until I cant hear any difference, that sometimes takes some time.... The homebrew receiver is easy though, I turn the bfo on and adjust the tuning till I get below say 20 Hz. The receiver and audio chain are good to at least 20 Hz and below that the S meter wags back and forth and the speaker cone (10 inch) goes in and out slowly. The BFO is a 455 KHz xtal oscillator and if I zero beat the signal, its centered in the passband. I think most modern receivers have a problem getting below 200 Hz in the audio chain, nor will the little speakers do anything but self destruct if they did get down to 20 Hz. That has nothing to do with CW I suppose, but it does on AM. That's why I hope the K3 will pass audio to 20 Hz, at least at the line level output. I can see on CW and SSB you want to restrict the audio to eliminate noise, but on AM its wonderful to have good fidelity at times. That's one reason why I have stuck with AM operation so long, I cant tune ssb so it sounds 'right' to me, and a good AM signal sounds like someone is in the room with me, or better! Brett N2DTS > > Most modern transceivers, including > the Elecraft rigs, have virtually no output within 100 Hz or so of the > carrier frequency, thanks to the excellent I.F. filters they > use. That makes > finding zero beat with the sidetone mandatory to avoid an > error or 100 Hz or > more in trying to tune onto the other station's frequency. > > Ron AC7AC > ================================== > My Drake R4C had good IF filters but I could move the filter > over to the > carrier frequency with the excellent passband tuning and > "see" the beat note > on the (analog) S meter. The needle would go from a fast > vibration to a > slower one with more movement as I approched zero beat. No > hearing needed. > This was how I set the xtal calibrator to zero beat with WWV. > Then , I > could read a frequency to the nearest khz, something I could > only dream of > with older rigs. > > 73 > Rick Dettinger > K7MW > > _______________________________________________ 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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Tone matching judgment - depending on what you're referring to, nobody
has it. Most people can identify which of two tones is higher or lower if they have enough pitch separation. As they get closer in pitch, people's ability to tell high or low (sharp or flat) goes away. At that point you have to listen to the beat pattern that the tones establish in your brain. I find it is pretty easy to do with the K2 PROVIDED I have the side tone output going through a good low pass filter to make it more of a pure sine wave. Once filtered, the signal and sidetone have the same "timbre" and detecting the beat frequency is much easier. In the music field, we use guitar tuners. They tell you if you're sharp of flat. I've often though of using a guitar tuner to tune CW. 622 Hz is an Eb, 659 Hz is an E. - Keith - -----Original Message----- From: Brett gazdzinski I find the K2 and other modern rigs hard to zero, as I have NO tone matching judgment. _______________________________________________ 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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On Thu, 12 Jul 2007, Darwin, Keith wrote:
> > In the music field, we use guitar tuners. They tell you if you're sharp > of flat. I've often though of using a guitar tuner to tune CW. 622 Hz > is an Eb, 659 Hz is an E. Those critters are really usefull...borrowed one last weekend to take to a workshop where we were making pan flutes out of bamboo...I completed mine first. But, just like cw, the skill trumps the technology (g). Thom,EIEIO Email, Internet, Electronic Information Officer k3hrn - admitted owner of leaky tune bucket. www.baltimorehon.com/ Home of the Baltimore Lexicon www.tlchost.net/hosting/ Web Hosting as low as 3.49/month _______________________________________________ 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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