In a message dated 7/12/07 6:57:27 AM Eastern Daylight Time, [EMAIL PROTECTED] writes:
> When I was first licensed with a novice class ticket (rock-bound), one > learned to > "tune the band" looking for answers. It was common-place to answer a > CQ by calling the CQer 5, 10, or even 50 kc away....5 or 10 kc away > often got results. 50kc was less common, but not rare. Yep. That was because xtals were expensive and nobody could own enough of them. And before the mid 1970s, Novices had to use crystal control. Now we have VFOs that can be set to within a few Hz of where we want them. We should use them! > I don't know what the fascination is with "zero beating" the guy > you're calling. It's good operating practice. Here's why: If two or more stations operate zero-beat with each other, they use the minimum possible amount of the band, *and* they keep that frequency busy throughout the QSO. If two stations operate non-zero-beat with each other, they use up to twice the minimum possible amount of the band. And they don't keep either frequency busy throughout the QSO, so the chances of someone unintentionally QRMing is much greater. Now before anybody says that this can be avoided by checking the frequency before transmitting, consider this scenario: Suppose that W1ABC & W6DEF are in QSO, and W1ABC is transmitting on 14.030 while W6DEF is on 14.050. Then W2GHI shows up on 14.030 and hears nothing, because he's in the skip zone for W1ABC. W2GHI sends "QRL?" and still hears nothing, and so starts sending CQ. W1ABC can't hear W2GHI either. But W2GHI is 599 plus at W6DEF, and is stepping all over W1ABC. W6DEF can't let W2GHI know about the QRM, because 'DEF is on 14.050. And even if W6DEF tells W1ABC, it will do no good, because W2GHI can't hear W1ABC The same thing can happen if W7JKL shows up on 14.050 and can't hear W6DEF. There are lots of similar situations possible even without a skip zone. Now suppose that W1ABC & W6DEF are in QSO, and both are on 14.030. If W2GHI shows up on 14.030 while W6DEF is transmitting, chances are W2GHI will hear W6DEF and know the frequency is busy. If W2GHI shows up while W1ABC is transmitting, he wil hear nothing, but as soon as W2GHI sends "QRL?", W6DEF can reply with "C" and let him know that the frequency is in use. The end result is that, by careful zero beating, the number of QSOs on the band can be doubled and the possibilities of unintentional QRM greatly reduced. Of course, with the advent of the K3 "super filters," > > this might become necessary if op's "crank 'em all the way down" for > routine CQs. I have found that CW zeroing really isn't that difficult, because I use a sharp filter almost all the time and just peak the received signal in the center of the filter passband. If the rig is set up correctly, I'm zeroed. Nothing new about this - here's what I was using for a receiver more than 30 years ago. Cost me about $10 to build: http://www.qsl.net/k5bcq/Jim/SilverRX1.jpg http://www.qsl.net/k5bcq/Jim/SilverRX2.jpg http://www.qsl.net/k5bcq/Jim/SilverRX3.jpg http://www.qsl.net/k5bcq/Jim/SilverRX4.jpg http://www.qsl.net/k5bcq/Jim/SilverRX5.jpg http://www.qsl.net/k5bcq/Jim/SilverRX6.jpg http://www.qsl.net/k5bcq/Jim/jiminfo.doc 73 de Jim, N2EY ************************************** Get a sneak peak of the all-new AOL at http://discover.aol.com/memed/aolcom30tour _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
