You're booming in down here, Ken - on my 'marginal' antenna. Hearing everyone fine, even ...Peter? DF...forgot the call between the radio room and here!
~ Todd, KA1KAQ/4 On Fri, Apr 3, 2009 at 7:29 PM, Ken <kenw2...@comcast.net> wrote: > thanks ! > > > ----- Original Message ----- > From: "Tom Prohigh" <t...@prohigh.com> > To: "'Discussion of AM Radio in the Amateur Service'" > <amradio@mailman.qth.net> > Sent: Friday, April 03, 2009 7:26 PM > Subject: Re: [AMRadio] 7160 tonight: Suggestion > > > 7160 > > -----Original Message----- > From: amradio-boun...@mailman.qth.net > [mailto:amradio-boun...@mailman.qth.net] On Behalf Of Ken > Sent: Friday, April 03, 2009 7:26 PM > To: Discussion of AM Radio in the Amateur Service > Subject: Re: [AMRadio] 7160 tonight: Suggestion > > what freq > > > ----- Original Message ----- > From: "Tom Prohigh" <t...@prohigh.com> > To: "'Discussion of AM Radio in the Amateur Service'" > <amradio@mailman.qth.net> > Sent: Friday, April 03, 2009 7:24 PM > Subject: Re: [AMRadio] 7160 tonight: Suggestion > > > Right now Timtron doing DX AM with Germany! > > > > -----Original Message----- > From: amradio-boun...@mailman.qth.net > [mailto:amradio-boun...@mailman.qth.net] On Behalf Of D. Chester > Sent: Friday, April 03, 2009 1:52 PM > To: amradio@mailman.qth.net > Subject: Re: [AMRadio] 7160 tonight: Suggestion > > >> From: "Todd, KA1KAQ" <ka1...@gmail.com> > >> On Thu, Apr 2, 2009 at 1:45 PM, D. Chester <k4...@charter.net> wrote: >>> One suggestion. We need to be more careful about zero beating each other >> on >>> the 40m frequency. At times in the QSO, stations are so scattered out >>> over >>> a 1-2 kHz range, that my sync detector won't stay locked when one station >>> turns it over to another. But the real problem is that this frequency >>> scattering is bound to be generating unnecessary hostility from the SSB >>> DX'ers, and will likely to result in deliberate QRM and other hostile >>> actions against the AM'ers > >> When has that ever bothered you before, Don? To borrow your own words >> on such matters, 'strap and ignore', 'turn up the wick' etc. I'd agree >> with you if folks were scattered out over 4-5 kcs or more, but 1-2 >> seems m ore related to sync detectors not locking up than to offending >> any SSB ops. After all, it's been one of the ways to discourage >> anti-AM SSB types from crowding in close to a QSO in progress. > > I have ALWAYS, ever since the early 60's, advocated operating zero-beat with > > the other station whenever possible. One exception might be when two or > more stations are xtal controlled, and some of the older VFOs do drift. But > > failure to zero-beat when it is easily possible and convenient is just plain > > sloppy operating. > > This is an example of the difference between necessary bandwidth and > occupied bandwidth. If you are running audio out to 5 kHz, 10 kHz is the > NECESSARY bandwidth of the signal. But if two stations in the QSO are 3 kHz > > apart, then the OCCUPIED bandwidth of the QSO becomes 13 kHz. There is no > rule that says all stations in a QSO have to be on the same frequency. > Hell, DX'ers routinely take up two whole SSB communications channels for one > > QSO by working split frequency (and these are often the very same > self-righteous kilocycle kops who gripe the loudest about all that > "bandwidth" that AM and ESSB signals take up). Nevertheless, conspicuous > sloppiness about zero-beating just unnecessarily gives the slopbucketeer > lunatic fringe more ammunition to use against AM. > > Another often-overlooked advantage of carefully zero-beating (whenever > practicable) is that a "breaking" station attempting to enter into the QSO > is less disruptive. If you can hear his audio underneath the transmitting > station, and at most, the puttering sound of a nearly zero-beat carrier, > this is far less disruptive to the conversation, than a loud 1-2 kHz squeal > of an off-frequency carrier, which garbles up the sidebands of both signals. > > You often miss what the transmitting station was saying, while at the same > time, missing the callsign of the breaking station. It is not unusual that > "breakers" into a QSO are ignored for this very reason. > > But older transmitters with drifty VFO's are not the only problem. Some of > the worst offenders are using modern transceivers on AM. Even if the audio > level and carrier level are adjusted properly, so that a good, undistorted, > plate-modulated quality AM signal is generated, many transceivers lack any > kind of frequency spotting function. In AM mode the received signal is > clearly audible as long as it lies within the transceiver's passband. So it > is easy to tune in the signal on the receiver and then transmit, and end up > with a carrier 1.5 kHz or more off frequency. If everyone is using a wide > bandpass at the receiver and there is little congestion on nearby > frequencies, this is no big deal and no-one may even notice. But if the > band is crowded and many stations in the QSO are operating with the receiver > > in narrow bandpass, with heavy QRM off to both sides, some people in the QSO > > may miss the call entirely. > > I have seen modifications to transceivers that allow a spotting function for > > zero-beating purposes. Depending on the circuit design, this may be very > easy with minimal alteration of the circuitry, while on others it simply > isn't practical. Lacking a spotting function, the easiest method would be > to put the rig in SSB/CW mode and zero-beat the AM carrier, then switch back > > to AM. But on some rigs, this automatically produces a frequency error, > because there is a built-in frequency offset when switching between modes. > In that case, you have to note the digital display frequency, and retune > back to that frequency in AM mode. Even then, there may also be an offset > in the digital display reading that must be taken into account. It is a > matter of figuring out exactly what works with a particular ricebox and > getting into the habit of using it. > > One factor that hinders proper zero-beating with any receiver is > space-shuttle quality, so-called "communications grade" audio, that cuts off > > everything below about 500 Hz. That makes it nearly impossible to hear two > carriers approach zero-beat, if the audio drops out once they are within > 300-500 Hz of each other. One more reason to have good low frequency > response at the receiver, working into a decent speaker or headphones. > > While it may be poor operating practice to intentionally operate on > scattered frequencies just to discourage SSB stations, that doesn't mean you > > should hesitate to go into the "SBE" mode when SSB stations intentionally > zero in and try to piggy-back ride the AM carrier. Then, to use a Timtron > expression, it may be time to "exit stage left" and move about 1.5 kHz down > into the LSB passband, and for each station in the QSO to operate a little > off frequency to make it necessary for the offending parasites to keep > changing frequency to keep up with you. But this should be used only as a > defensive tactic in the presence of deliberate QRM, not as a preventive > measure. When the QRM finally goes away, then everyone should re-zero beat. > > Something that I have experienced many many times, is for the offending > slopbucketeers to zero-beat, so I exit stage left. The other AM station in > QSO zero-beats me. Then the SSB'ers re-zero beat to ride the carrier. So > we exit stage left once again. This continues for several more > transmissions, until we are 5-6 kHz down from the original frequency. Then, > without fanfare, we move back up to the original frequency. Sometimes the > SSB QSO stays down below, and we all co-exist peacefully. At other times > the slopbucketeers move back up to zero-beat us. When that happens, they > have clearly demonstrated that the interference is intentional. Once, > someone from an FCC monitoring station (remember those?) explained that if > one amateur station merely transmits on top of another, it is not considered > > deliberate and no "pink slip" will be issued, because amateur radio operates > > on an interference-expected basis. But if the operators in the original QSO > > move frequency, and the interfering station follows them to the new > frequency to continue causing interference, the FCC considers that to be > deliberate. > > But rather than getting into a pissing contest with jammers, it is > sometimes better to just pretend they don't exist and ignore them. "Strap > softly and turn up the wick." > > All said, careful zero-beating is even more essential in the 7125-7200 > segment during prime time after-work hours, which just happens to > simultaneously be prime time for cross-country propagation AND for European > grey-line DX propagation. Because of the outmoded subband restrictions that > > presently exist on 40m in continental US, the overlap between the new > privileges enjoyed by European and other DX stations, and US phone > privileges, is only 75 kHz. One AM QSO occupying 7.5 kHz, about the minimum > > actual bandwidth occupied by a real-world AM signal, is fully 10% of the > entire segment, while ZILLIONS of the "Hello-g'bye, ur five-nine, pse QSL, > 73, QRZ?" DX'er types are just getting home from work to play a little radio > > before dinner, or are getting in some last minute DX before bedtime in > Europe. Sloppily operating in a manner such that we occupy 15-20% of the > segment for one round-table will do nothing but attract the massive > wholesale wrath of this element, which will eventually generate unwanted > anti-AM sentiment within the greater amateur community, and possible > lobbying efforts and FCC petitions to restrict or downright outlaw AM. > > To repeat a cliché, we need to keep our ducks in a row while using the 7160 > frequency. > > Don k4kyv > > _______________________________________________________________ > > This message was typed using the DVORAK keyboard layout. > > http://www.mwbrooks.com/dvorak/ > > http://gigliwood.com/abcd/ > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.285 / Virus Database: 270.11.37/2036 - Release Date: 04/03/09 > 06:19:00 > > No virus found in this outgoing message. > Checked by AVG - www.avg.com > Version: 8.5.285 / Virus Database: 270.11.37/2036 - Release Date: 04/03/09 > 06:19:00 > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.285 / Virus Database: 270.11.37/2036 - Release Date: 04/03/09 > 06:19:00 > > No virus found in this outgoing message. > Checked by AVG - www.avg.com > Version: 8.5.285 / Virus Database: 270.11.37/2036 - Release Date: 04/03/09 > 06:19:00 > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. 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