++++++++++++++++++++ To: Elecraft Reflector Date: Thu, 17 Jan 2002 13:04:18 -0700 (MST) From: cyr999 at extremezone.com Subject: [Elecraft] On zero beating Hi folks - Although it may be clear as a bell to most people, I thought I would share my experinces as a beginner with zero beating. It may be of interest to newcomers in HAM. Every text I've read seems to define zero beat by referring to the word "beat". I never HEARD any "beat". What the heck was everyone talking about! I never new what that "beat" was and finally got too embarassed to ask people anymore about it. In the mean time I would tune in on a signal by simply using SPOT and matching the tone by ear. Since I play the violin, this is very easy for me. On the other hand, my Code Buddy from FISTS finds that type of thing almost impossible. The other way I tune is simply to get the signal as loud as I can in the narrowest filter setting. With my K1 and K2 that seems to always be just about dead on. For you fellow beginners, I was FINALLY enlightened when installing the AF filter the other nite. The manual said to zero beat the CONTINUOUS tone at 7000.00. MAGICALLY WHEN THERE IS A CONTINUOUS TONE ZERO THE DEFINITION OF BEAT BECOMES TOTALLY OBVIOUS. As soon as you are dead on the two tones sound as if they are one tone which has a rhythmic rise and fall of the tone. This rise of the tone is the beat. When you listen to code being sent, you do not have a CONTINUOUS wave - so you seldom have the signal coming in long enough to hear this illusive beat!!!! Key word here: continuous :-) I guess what I am trying to share is what the word BEAT really refers to if you were confused like me. Also, once I heard what the beat was on the contiuous wave, it helped me with matching the SPOT even more - you may not hear the beat per se when receiving code, but you can hear when it's getting right in the groove. Perhaps listening to really fast ops sends such a rapid signal that you hear even more of a beat. Anyway, I found this simple thing to be a true revelation. If it's confused you - go down to 7000 without the antenna etc etc and you will be able to learn the true basis of the word BEAT. Sorry to bore you experienced folks with this simplicity!! If I've said anything that needs correction or the voice of experience - please jump in so I don't mislead anyone! 73/KB7OEX Tim Logan +++++++++++++++++++ To: cyr999 at extremezone.com Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] On zero beating From: "Steve Lawrence" Date: Thu, 17 Jan 2002 15:45:43 -0500 Tim, I too have found this difficult to hear with a discontinuous CW signal. The "beat" is produced by the difference in the two audio frequencies: the spot tone and the apparent tone of the CW signal. The beat frequency goes down as the differences are minimized further, until the beat is zero -- indicating perfect match in frequency. The ear hears a subtle Wah...wah...wah...wah which is the beat note indicating the frequencies are not quite matched. A slight change in the tuning dial, increases or decreases the period of the beat note or the separation of the wah.......wah......wah...... The desire is to decrease the beat resulting in matched frequencies. This is easy for me to hear when tuning my guitar, and I suspect a violin to be much the same. Here the tones are long and continuous. But the key, as you well point out, is two continuous tones -- not the case in spotting a CW signal. So, like you, I struggle on the non-continuous signal. Perhaps the "ultimate" spotting tool would be to measure the audio frequency of a received CW signal and display it -- perhaps at the touch of a button. Knowing your sidetone is set to, say 700Hz, you could then adjust the dial frequency so the received CW signal is also at 700 Hz. Since the K2 has a frequency counter logic, perhaps this feature could be implemented? Steve aa8af +++++++++++++++++++ Reply-To: From: "Ron D' Eau Claire" To: "Steve Lawrence" , Cc: Subject: RE: [Elecraft] On zero beating Date: Thu, 17 Jan 2002 23:26:04 -0800 Steve AA8AF wrote: > Perhaps the "ultimate" spotting tool would be to measure the audio > frequency of a received CW signal and display it -- perhaps at the touch > of a button. Knowing your sidetone is set to, say 700Hz, you could then > adjust the dial frequency so the received CW signal is also at 700 Hz. > Since the K2 has a frequency counter logic, perhaps this feature could be > implemented? A simpler system that has been used in many older rigs is to simply push a button to offset the 'vfo' by the beat note, so you adjust the tuning for zero tone (true "zero beat") where there is no audio tone produced at all. The problem with that is that newer rigs cut off the audio response below a couple of hundred Hz, so you can't really hear the "zero" very well. Besides, once you know what to listen for, it is no problem at all to hear the beat even with a CW signal being keyed. If you can hear the CW, you will quickly learn to hear the tone as well. One problem with hearing the tone that many ops have is that they are too different in level. If you like the sidetone very LOUD you will have to turn up the signal to come close to it in order to hear the beat clearly, and visa versa. Ron AC7AC K2 # 1289 +++++++++++++++++++ Reply-To: "Bob Lewis (AA4PB)" From: "Bob Lewis (AA4PB)" To: Subject: Re: [Elecraft] On zero beating Date: Fri, 18 Jan 2002 07:56:02 -0500 There's a circuit floating around somewhere that uses a PLL chip to detect the received audio tone and light an LED when it is correct. Just tune until the LED lights and you zero beat. ++++++++++++++++++++++ Date: Fri, 18 Jan 2002 09:58:45 -0600 From: "George, W5YR" To: Steve Lawrence Cc: cyr999 at extremezone.com, elecraft at mailman.qth.net Subject: Re: [Elecraft] On zero beating That "ultimate spotting tool" is as near as your computer connected to your radio audio output and running any of the PSK31 programs with a waterfall display or the SpectroGram program. With such displays, one can readily identify the offset tone frequency being heard and can then adjust the tuning to present exactly the desired tone. For example, I prefer an offset of 700 Hz so I have a waterfall marker set on my PSK31 program at 700 Hz. When tuning in a CW signal, I merely tune until the signal "track" is placed under the marker. Then I will be transmitting directly upon the other station's frequency and will hear that station at an audio frequency of 700 Hz. I have found this method superior to all others, plus it gives you a panoramic display of other cw signals within the receiver filter passband being displayed. Of course, this approach requires that a computer be present and running the proper program so it wouldn't have much appeal for portable operation unless a laptop were available. But, for home station use, it is a valuable tool to have when working CW. 72/73/oo, George W5YR - the Yellow Rose of Texas ++++++++++++++++ Date: Fri, 18 Jan 2002 10:09:45 -0600 To: elecraft at mailman.qth.net From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] On zero beating Fellas: You don't have to be able to hear the 'beat' (or to dance to the music... but then I digress...) if you can merely tune the received signal such that it 'disappears' WITHIN the sidetone. As you tune the received signal thru the sidetone, there will be a point at which they will merge and be one... you'll hear the sidetone just as before, but you will note that the received signal just makes the sidetone appear to be slightly louder during the moments when the received signal is present. THIS is akin to being ZERO BEAT by other methods... and is often much easier to achieve than actually trying to HEAR the beat note (mathematical difference between the received tone and the sidetone). 73 - Tom Hammond N0SS ++++++++++++++++++ From: "KC0IFL" To: Subject: Re: [Elecraft] On zero beating Date: Sat, 19 Jan 2002 10:38:45 -0600 I have done this and it really does work! "CW Get" works also. Anything that will show the audio frequency on the computer screen. Ron E. ----- Original Message ----- From: "George, W5YR" To: "Steve Lawrence" Cc: ; Sent: Friday, January 18, 2002 9:58 AM Subject: Re: [Elecraft] On zero beating > That "ultimate spotting tool" is as near as your computer connected to your > radio audio output and running any of the PSK31 programs with a waterfall > display or the SpectroGram program. -- snip -- +++++++++++++++++ Date: Sat, 19 Jan 2002 13:57:36 -0800 From: lhlousek Subject: Re: [Elecraft] On zero beating To: elecraft at mailman.qth.net <> Doing it by ear is certainly the lowest power way and probably the fastest way once you get good at it. For me, I consider beating a CW sig by ear to be a skill that should be developed as part of becoming a proficient CW op. Lou W7DZN ++++++++++++++ Reply-To: "Bob Lewis (AA4PB)" From: "Bob Lewis (AA4PB)" To: "K2 List" Subject: Re: [Elecraft] On zero beating Date: Sat, 19 Jan 2002 17:42:07 -0500 > Couldn't one use a PLL to drive a bargraph display The easiest way is to just use a PLL with an LED "lock" indicator. When you get the tone frequency close enough for the PLL to lock you are very close. +++++++++++++++ Date: Sat, 19 Jan 2002 16:26:11 -0800 From: lhlousek Subject: Re: [Elecraft] Zero beating To: Douglas Westover , elecraft at mailman.qth.net <<>> Zero beating means tuning to the same exact frequency as the station you are working. Being on same frequency minimizes the bandwidth needed for the Q and keeps both stations centered in each other's filters. This is considered to be good operating practice. Working a pileup is a little different situation. As you say, it is often to good to be offset 100Hz or so. But being able to tell how much you are offset and in which direction is actually more difficult than zero beating. Of course, if the a station is working split then by definition there is no zero beating. Lou W7DZN +++++++++++++++++ From: "Jonathan Taylor, K1RFD" To: "Douglas Westover" , , =?iso-8859-1?Q?D.R._Weiss_KI=D8RP?= Subject: Re: [Elecraft] Zero beating Date: Sun, 20 Jan 2002 13:32:01 -0500 Actually, I have found that for net operations it's useful to be very close to the NCS frequency but not EXACTLY on it. Otherwise, it makes it difficult for those monitoring the net to distinguish NCS's signal from the others. Just as phone ops have different voices, I find it useful for the various stations on a net to have slightly different pitches. ----- Original Message ----- From: "D.R. Weiss KIØRP" To: "Douglas Westover" ; Sent: Saturday, January 19, 2002 9:41 PM Subject: Re: [Elecraft] Zero beating My reply was in the context of CW traffic ops -- the closer to NCS, the better. +++++++++++++++++ From: "Dan Barker" To: Subject: RE: [Elecraft] Zero beating Date: Sun, 20 Jan 2002 18:25:09 -0500 Also, being on freq makes the filters useful; Else, the signal as well = as the noise falls outside the skirts. As to how to use the Spot tone; I found it difficult, and even posted to = this group to run CWGet or Spectrogram because they are so easy adn = spotting is so hard to do (in my youth, I built a little led gizmo to = SHOW me the way). Well, if you zero-beat 10 times while listening to the = Spot tone AND watching the Spectrogram display, you'll figure it out. It = becomes easy. It's been hard for me for [let's just say over 20 years] = and it's been easy for several days. After a few minutes practice, you = can leave the laptop at home and hit the Appalachian trail. Dan / WG4S ++++++++++++++++