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How wide is a Moirse CW pulse?
The question kind of states it. I suppose that the BW might be wider as
the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. What the heck , over? - Mike KB3EIA - |
In article , Mike Coslo
writes: The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, The bandwidth of a Morse signal is determined by the rise and fall times of the leading and trailing edges of each dit or dah, and the shape of the rise and fall. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. Who is "we", Mike? And it's some 700 kHz wide!!! How did you determine the bandwidth? And now I'd swear it's almost 3kHz wide. That's like SSB!!! Yep. Such a bandwidth would require extremely "hard" keying, though. Or a modulated carrier. Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Was the AGC on? 73 de Jim, N2EY |
Mike Coslo wrote in message t...
The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, I believe the bandwidth actually decreases as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Bummer, hope it was just a one-time anomaly. What the heck , over? - Mike KB3EIA - 73 de Bert WA2SI |
Mike,
Sounds to me like you were experiencing front end overload in your receiver ... when the signal exceeds the dynamic range of your receiver, all sorts of things happen and the signal can appear to be MUCH wider than it actually is. To verify this, turn off the preamp (if you have one), and switch in about 20 dB of attenuation before the front end of the receiver and see if it all gets better ... 73, Carl - wk3c "Mike Coslo" wrote in message ... The question kind of states it. I suppose that the BW might be wider as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. What the heck , over? - Mike KB3EIA - |
From the ARRL License Manual 1976:
CW Bandwidth = wpm X 4 (e.g., 40 WPM = 160 Hz) "With proper shaping, the necessary keying bandwidth is equal to 4 times the speed in words per minute for International Morse Code; e.g. at 25 words per minute, the bandwidth is approximately 100 cycles." -- 73 From The Wilderness Keyboard ================================== "Mike Coslo" wrote in message ... The question kind of states it. I suppose that the BW might be wider as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. What the heck , over? - Mike KB3EIA - |
From the ARRL License Manual 1976: CW Bandwidth = wpm X 4 (e.g., 40 WPM = 160 Hz) "With proper shaping, the necessary keying bandwidth is equal to 4 times the speed in words per minute for International Morse Code; e.g. at 25 words per minute, the bandwidth is approximately 100 cycles." Also -- suspect your receiver bandwidth and dynamic range -- try some attenuation and reduce RF gain or Kenwoods AIP -- helps with strong adjacent signals. 73 From The Wilderness Keyboard ================================== "Mike Coslo" wrote in message ... The question kind of states it. I suppose that the BW might be wider as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. What the heck , over? - Mike KB3EIA - |
"Mike Coslo" wrote in message ... The question kind of states it. I suppose that the BW might be wider as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Did you mean 700Hz wide (you typed 700kHz). Cheers, Bill K2UNK |
"N2EY" wrote in message ... In article , Mike Coslo writes: The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, The bandwidth of a Morse signal is determined by the rise and fall times of the leading and trailing edges of each dit or dah, and the shape of the rise and fall. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. Who is "we", Mike? And it's some 700 kHz wide!!! How did you determine the bandwidth? And now I'd swear it's almost 3kHz wide. That's like SSB!!! Yep. Such a bandwidth would require extremely "hard" keying, though. Or a modulated carrier. Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Was the AGC on? 73 de Jim, N2EY Part of the equation here is the receiver, as Jim N2EY was bringing up. A lot of folks don't understand that actual bandwidth and apparant bandwith as determined by a receiver are not the same in most cases. Also I really don't see the problem, why did you just sit there? Were you all rock bound or what? Move frequency, were not channelized, yet. Dan/W4NTI |
"Bert Craig" wrote in message om... Mike Coslo wrote in message t... The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, I believe the bandwidth actually decreases as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Bummer, hope it was just a one-time anomaly. What the heck , over? - Mike KB3EIA - 73 de Bert WA2SI A one time anomaly????? W1AW is a bulletin station. Been there, on or about for 90 years. Dan/W4NTI |
N2EY wrote: In article , Mike Coslo writes: The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, The bandwidth of a Morse signal is determined by the rise and fall times of the leading and trailing edges of each dit or dah, and the shape of the rise and fall. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. Who is "we", Mike? Just a number of Hams using PSK31. I was only monitoring, so I didn't keep track of callsigns. And it's some 700 kHz wide!!! How did you determine the bandwidth? On the waterfall display, you can look at the BW pretty directly. A good psk31 signal doesn't take up a whole lot of space, maybe 40 hz. This CW signal had spikes on the end that extended almost 400 hz on each side. It ripped into the PSK signal and wiped it out. When it got really bad, everyone just gave up. And now I'd swear it's almost 3kHz wide. That's like SSB!!! Yep. Such a bandwidth would require extremely "hard" keying, though. Or a modulated carrier. Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Was the AGC on? Both on and off. I often have to turn it off when a strong signal desenses the reciever and I'm working a weak station. Your modulated carrier thing may just be a big clue. When the signal ended up putting spikes over the whole section of the band, I removed the connection to the computer to listen to the signal. It sounded pretty strange. I'll have to check what the signal again to see what it sounds like on ssb or even AM. But in these K1MAN days, it would be a good idea for ARRL to keep a good clean signal, and not do the eqivelant of K1MAN - that is to just start the transmission and stomp all over everyone else nearby. |
Carl R. Stevenson wrote: Mike, Sounds to me like you were experiencing front end overload in your receiver ... when the signal exceeds the dynamic range of your receiver, all sorts of things happen and the signal can appear to be MUCH wider than it actually is. To verify this, turn off the preamp (if you have one), and switch in about 20 dB of attenuation before the front end of the receiver and see if it all gets better ... Will do. Thanks Carl. The other users wer complaining about it too, but they could have been experiencing the same problem. - Mike KB3EIA - |
Bill Sohl wrote: "Mike Coslo" wrote in message ... The question kind of states it. I suppose that the BW might be wider as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Did you mean 700Hz wide (you typed 700kHz). Yikes! Yep that was 700 Hz. A 700 kHz signal would be something indeed! I see I misspelled Morse too...... Just got a new computer, and was probably too excited last night! 8^) - Mike KB3EIA - |
"Mike Coslo" wrote The question kind of states it. I suppose that the BW might be wider as the speed increases. There are three different bandwidths that come into play. They are "necessary bandwidth", "effective (or actual) bandwidth", and "apparent bandwidth" Necessary bandwidth in hertz for copying a morse signal is defined as Bn=BK where B is modulation rate measured in Baud, and K is an overall numerical factor which depends on the allowable signal distortion. The commonly used values of K are 3 for non-fading paths, 5 for fading paths, and 8 for fading/multipath smearing. From the formula you can see that higher speeds (Baud) require more bandwidth, just as you supposed. The nominal "necessary bandwidth" presumed for CW is 100Hz which is based on 25WPM (20 Baud) over a fading path (B=20, K=5). Quite honestly, "necessary bandwidth" is primarily an academic exercise and planners tool, as it ignores some practical 'real world' issues and doesn't answer the question raised in your subject line. Effective bandwidth is an actual on-the-air measurement of the width of the signal at some designated level, most commonly -60dB referenced to the peak. To understand what is being measured, you need to recognize that Morse is sent as an amplitude modulated carrier (AM) and that it contains sidebands. Like any AM signal, those sidebands extend nominally plus/minus the carrier at the frequency of the modulation, or BW=2M. Modulation of this signal contains two components. The first component is the baud rate of the actual on/off keying (see "necessary bandwidth" above). Were it only for this component, measured CW signals would be very narrow, 100Hz, and dependent totally on keying speed. The second modulation component is related to the rise time of the radiated signal. Fast rise times (where the RF envelope resembles a square wave) generate signals rich in harmonics and as these harmonics mix with the primary signal and each other in the transmitter stages, they produce sum and difference signals which become part of the sidebands of the radiated signal. The sharper the rise time and the more non-linear the transmitter stages, the more energy there is in the harmonics, and thus the bandwidth is wider (as measured at -60dB skirt points). Controlling this component of bandwidth can take the form of regulating the rise time (shaping in the keying circuit) and ovoiding overdriving of transmitter circuits. The third kind of bandwidth is "apparent bandwidth". This bandwidth is determined by the effective bandwidth (see above) AND the performance of the receiver environment. If a receiver were "perfect", then effective and apparent bandwidth would be equal (the receiver would perfectly reproduce the desired signal in the form it arrived at its antenna and would reject the effects of all non-target signals present.) But receivers aren't perfect (well, maybe my Sherwood equipped R4C is close). Extremely loud signals (your neighbor 3 doors away) will sound ("apparent") several hundred kHz wide, because your receivers AGC will pump, RF and IF stages will be overloaded, and the faster he sends the worse it will be. I'm giving the obvious extreme example, but just to make the point. Many times just some reasonable adjustments of your receiver such as turning off noise blankers, reducing the preamp level, or turning your antenna will reduce the apparent bandwidth down in line with the actual bandwidth of the transmitted signal. 73, de Hans, K0HB |
"Dan/W4NTI" w4nti@get rid of this mindspring.com wrote in message thlink.net...
"Bert Craig" wrote in message om... Mike Coslo wrote in message t... The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, I believe the bandwidth actually decreases as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Bummer, hope it was just a one-time anomaly. What the heck , over? - Mike KB3EIA - 73 de Bert WA2SI A one time anomaly????? W1AW is a bulletin station. Been there, on or about for 90 years. Dan/W4NTI Geez Dan, I thought it might've been a malfunction at W1AW...hence the "anomaly" statement. 73 de Bert WA2SI |
Mike Coslo wrote:
The question kind of states it. I suppose that the BW might be wider as the speed increases. CW code signals are around 100Hz wide, IIRC. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! It might seem so if your receiver was in SSB mode. A narrowband signal will still be heard throughout the passband of a filter set for a wideband mode. Also, if you were in CW receive mode instead, the receiver's AGC will make the attenuation of that filter's side skirts seem worse. What would be 10dB down without AGC will look like only say 3dB if the AGC is enabled. Especially as you mentioned (below) that w1aw was a strong signal. Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. |
In article , Mike Coslo
writes: How did you determine the bandwidth? On the waterfall display, you can look at the BW pretty directly. A good psk31 signal doesn't take up a whole lot of space, maybe 40 hz. A Morse signal set up for optimal BW at 50 wpm takes up about 200 Hz. This CW signal had spikes on the end that extended almost 400 hz on each side. It ripped into the PSK signal and wiped it out. When it got really bad, everyone just gave up. Key clicks. Could be caused by a problem at Newington, or by a problem at the receiver end. And now I'd swear it's almost 3kHz wide. That's like SSB!!! Yep. Such a bandwidth would require extremely "hard" keying, though. Or a modulated carrier. Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Was the AGC on? Both on and off. I often have to turn it off when a strong signal desenses the reciever and I'm working a weak station. But did you also turn down the RF gain and turn up the AF? Or kick in an attenuator? What WK3C posted earlier is correct - if a strong signal overloads your receiver, its bandwidth may appear to be wider than it really is. If someone is running PSK31 using the usual SSB-rig-feeding-a-soundcard approach, overload of the receiver is a real possibility. What was your setup? Your modulated carrier thing may just be a big clue. When the signal ended up putting spikes over the whole section of the band, I removed the connection to the computer to listen to the signal. It sounded pretty strange. I'll have to check what the signal again to see what it sounds like on ssb or even AM. Sure. btw, W1AW's 80m CW freq is advertised as 3581.5 IIRC. Oddly enough, last night I was "reading the mail" from W1AW on 40 meters while packing up some parts I sold. Signal was very clean on my Southgate Type 7. I'm not sure of the exact time, but the transmission ended with "END OF 35 WPM" ;-) But in these K1MAN days, it would be a good idea for ARRL to keep a good clean signal, and not do the eqivelant of K1MAN - that is to just start the transmission and stomp all over everyone else nearby. The transmitters at W1AW are all Harris "professional grade" transceivers, one for each band plus a spare. Computer controlled from the main console, no adjustments needed to the rig itself. But even Harris stuff can have problems. Separate antennas for each band, too - the 80/75 antenna is a cage dipole between two of the towers. 80 feet up if it's a foot. I'll tune down to 80 tonight if I get the chance and see how W1AW sounds. 73 de Jim, N2EY |
Mike,
You're received a number of good answers. As for measuring bandwidth, I've used exactly two receivers that would be suitable for accurate measurement, and I couldn't afford either of them. With stability measured in 10 to the 9th power and accuracy at 10 to the 8th, these little babes were well over $50,000 in the mid 90s. LOL. Oh, and that doesn't include the cost of the IF spectrum analyser that was connected to one of them, nor any other costs such as calibrated antennas. As stated, the rise and fall times of the waveform determine the bandwidth; often the receiver can deceive you as to what the bandwidth is. Of course, it is possible there may have been a problem at W1AW. 73 from Rochester, NY Jim AA2QA "Mike Coslo" wrote in message ... The question kind of states it. I suppose that the BW might be wider as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. What the heck , over? - Mike KB3EIA - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.558 / Virus Database: 350 - Release Date: 1/2/04 |
In article k.net,
"Dan/W4NTI" w4nti@get rid of this mindspring.com writes: W1AW is a bulletin station. Been there, on or about for 90 years. Actually about 66 years (1938). In all that time there have been only three main rigs - the original rackpanel jobs, the 1960s ones installed about the time the "new" Hq building went up, and the Harris setup from the mid-90s renovations. Something like 25-30 years of service per setup. Trivia Quiz: There was an ARRL HQ station before W1AW. What was its callsign? There's a second callsign for the ARRL lab. What is/was it? 73 de Jim, N2EY |
On Sat, 03 Jan 2004 20:21:22 GMT, KØHB wrote:
Effective bandwidth is an actual on-the-air measurement of the width of the signal at some designated level, most commonly -60dB referenced to the peak. IIRC the accepted standard for measuring occupied bandwidth is -26 dB, which includes 99% of the signal. -- 73 de K2ASP - Phil Kane |
N2EY wrote:
Trivia Quiz: There was an ARRL HQ station before W1AW. What was its callsign? W1MK, I think located near Brainard Field, Hartford. There's a second callsign for the ARRL lab. What is/was it? Memory fails... Dave K8MN |
Bert Craig wrote: "Dan/W4NTI" w4nti@get rid of this mindspring.com wrote in message thlink.net... "Bert Craig" wrote in message .com... Mike Coslo wrote in message t... The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, I believe the bandwidth actually decreases as the speed increases. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Bummer, hope it was just a one-time anomaly. What the heck , over? - Mike KB3EIA - 73 de Bert WA2SI A one time anomaly????? W1AW is a bulletin station. Been there, on or about for 90 years. Dan/W4NTI Geez Dan, I thought it might've been a malfunction at W1AW...hence the "anomaly" statement. I was kind of hoping that it was a problem too. I've seen other CW signals on the waterfall, and they aren't that wide or nasty looking. Hopefully W1AW has been putting out a better looking signal for most of thos 90 years! 8^) - Mike KB3EIA - |
Robert Casey wrote: Mike Coslo wrote: The question kind of states it. I suppose that the BW might be wider as the speed increases. CW code signals are around 100Hz wide, IIRC. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! It might seem so if your receiver was in SSB mode. A narrowband signal will still be heard throughout the passband of a filter set for a wideband mode. Also, if you were in CW receive mode instead, the receiver's AGC will make the attenuation of that filter's side skirts seem worse. What would be 10dB down without AGC will look like only say 3dB if the AGC is enabled. Especially as you mentioned (below) that w1aw was a strong signal. Okay, but would it wreck the other signals as a matter of course? That's what I worry about. Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. |
Jim Hampton wrote:
Mike, You're received a number of good answers. As for measuring bandwidth, I've used exactly two receivers that would be suitable for accurate measurement, and I couldn't afford either of them. With stability measured in 10 to the 9th power and accuracy at 10 to the 8th, these little babes were well over $50,000 in the mid 90s. LOL. Oh, and that doesn't include the cost of the IF spectrum analyser that was connected to one of them, nor any other costs such as calibrated antennas. As stated, the rise and fall times of the waveform determine the bandwidth; often the receiver can deceive you as to what the bandwidth is. Of course, it is possible there may have been a problem at W1AW. W1AW trouble would be my guess. The signal didn't "look right", which is to say it didn't look like the CW signals we've coexisted with on 3580 until now. And the other ops were complaining about it too, and some were a good deal further from W1AW than I am. - Mike KB3EIA - |
Mike Coslo wrote:
Robert Casey wrote: Mike Coslo wrote: The question kind of states it. I suppose that the BW might be wider as the speed increases. CW code signals are around 100Hz wide, IIRC. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! It might seem so if your receiver was in SSB mode. A narrowband signal will still be heard throughout the passband of a filter set for a wideband mode. Also, if you were in CW receive mode instead, the receiver's AGC will make the attenuation of that filter's side skirts seem worse. What would be 10dB down without AGC will look like only say 3dB if the AGC is enabled. Especially as you mentioned (below) that w1aw was a strong signal. Okay, but would it wreck the other signals as a matter of course? That's what I worry about. Don't know if anyone has yet quizzed you as to whether you had your noise blanker activated. That could cause the things you mention. Dave K8MN |
"Phil Kane" wrote IIRC the accepted standard for measuring occupied bandwidth is -26 dB, which includes 99% of the signal. For regulatory purposes, I think you're probably correct (or close to correct --- -30dB sticks in my mind). Path engineering types tend to be more conservative because we actually have to make the circuit work. Since bandwidth is a constrained resource, communications planners tend to treat it like money and "make less do more" --- when you're aiming for BER's of better than 1 x 10 to minus10, your 1% of remaining energy can pretty badly farkle up an adjacent path. 73, de Hans, K0HB |
"N2EY" wrote There was an ARRL HQ station before W1AW. What was its callsign? ----- W1MK There's a second callsign for the ARRL lab. What is/was it? ----- W1INF More trivia: There is an IARU HQ call sign. What is it? While it may have a certain familiarity about it, especially the suffix, what is the significance of the prefix? 73, de Hans, K0HB |
Dave Heil wrote: Mike Coslo wrote: Robert Casey wrote: Mike Coslo wrote: The question kind of states it. I suppose that the BW might be wider as the speed increases. CW code signals are around 100Hz wide, IIRC. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. And it's some 700 kHz wide!!! And now I'd swear it's almost 3kHz wide. That's like SSB!!! It might seem so if your receiver was in SSB mode. A narrowband signal will still be heard throughout the passband of a filter set for a wideband mode. Also, if you were in CW receive mode instead, the receiver's AGC will make the attenuation of that filter's side skirts seem worse. What would be 10dB down without AGC will look like only say 3dB if the AGC is enabled. Especially as you mentioned (below) that w1aw was a strong signal. Okay, but would it wreck the other signals as a matter of course? That's what I worry about. Don't know if anyone has yet quizzed you as to whether you had your noise blanker activated. That could cause the things you mention. Nope, Just checked, and it is off. Not going to be much PSK on 3580 tonight. Must be an RTTY contest going on. Never saw so many RTTY signals at one time! - Mike KB3EIA - |
"Phil Kane" wrote in message et... On Sat, 03 Jan 2004 20:21:22 GMT, KØHB wrote: Effective bandwidth is an actual on-the-air measurement of the width of the signal at some designated level, most commonly -60dB referenced to the peak. IIRC the accepted standard for measuring occupied bandwidth is -26 dB, which includes 99% of the signal. -- 73 de K2ASP - Phil Kane That's the ANSI standard spec ... however it's not universally used. Carl - wk3c |
"KØHB" wrote in message hlink.net... "N2EY" wrote There was an ARRL HQ station before W1AW. What was its callsign? ----- W1MK There's a second callsign for the ARRL lab. What is/was it? ----- W1INF More trivia: There is an IARU HQ call sign. What is it? While it may have a certain familiarity about it, especially the suffix, what is the significance of the prefix? 73, de Hans, K0HB 4U1ITU is the station of the International Amateur Radio Club at ITU HQ in Geneva ... I've operated the station. The significance of the prefix is that 4U's are UN callsigns. 73, Carl - wk3c |
"Carl R. Stevenson" wrote 4U1ITU is the station of the International Amateur Radio Club at ITU HQ in Geneva ... I've operated the station. The significance of the prefix is that 4U's are UN callsigns. I'm not speaking of the ITU but the IARU (not the same thing at all). The IARU HQ station is not associated with the UN (nor the ITU) so does not have a "4U" prefix. 73, de Hans, K0HB |
In article k.net, "KØHB"
writes: "N2EY" wrote There was an ARRL HQ station before W1AW. What was its callsign? ----- W1MK You are correct, sir! And before that, it was 1MK There's a second callsign for the ARRL lab. What is/was it? ----- W1INF "It's Never Finished" - again correct. More trivia: There is an IARU HQ call sign. What is it? That's easy: NU1AW While it may have a certain familiarity about it, especially the suffix, what is the significance of the prefix? The original system for licensed amateur calls was a number and two or three letters. Maxim held 1AW, for example. This worked fine until amateur began working internationally and there was no way to tell what country a ham was in. When the first shortwave QSO was made by in November of 1925, the stations involved were 1QP, 1MO and 8AB - the last one being in France. So amateurs invented the idea of unofficial prefixes. "NU" meant "North america, United states". So while Maxim's call was shown on the license as 1AW, on the air he would use NU1AW to indicate where he was. Other countries had different prefixes, all according to the unoffficial system To emphasize that the prefixes were unofficial, they were usually written lower case: nu1AW The situation was finally sorted out at one of the radio conferences of the '20s (1927, I think) and the USA decided that American ham calls would all start with W (in CONUS) and K (outside CONUS). 73 de Jim, N2EY |
"KØHB" wrote in message hlink.net... "Carl R. Stevenson" wrote 4U1ITU is the station of the International Amateur Radio Club at ITU HQ in Geneva ... I've operated the station. The significance of the prefix is that 4U's are UN callsigns. I'm not speaking of the ITU but the IARU (not the same thing at all). The IARU HQ station is not associated with the UN (nor the ITU) so does not have a "4U" prefix. 73, de Hans, K0HB Sorry Hans. I misread your query. 73, Carl - wk3c |
In article , Dave Heil
writes: N2EY wrote: Trivia Quiz: There was an ARRL HQ station before W1AW. What was its callsign? W1MK, I think located near Brainard Field, Hartford. You are correct, sir! Heavily damaged in the flood of '36, as I recall. There's a second callsign for the ARRL lab. What is/was it? Memory fails... W1INF 73 de Jim, N2EY |
Dan/W4NTI wrote:
"N2EY" wrote in message ... In article , Mike Coslo writes: The question kind of states it. I suppose that the BW might be wider as the speed increases. Mike, The bandwidth of a Morse signal is determined by the rise and fall times of the leading and trailing edges of each dit or dah, and the shape of the rise and fall. The reason I ask is that on 3580 tonight, we're all sitting there fat, dumb, and happy, when W1AW starts it's CW broadcast. Who is "we", Mike? And it's some 700 kHz wide!!! How did you determine the bandwidth? And now I'd swear it's almost 3kHz wide. That's like SSB!!! Yep. Such a bandwidth would require extremely "hard" keying, though. Or a modulated carrier. Needless to say, their strong signal was pretty tough on all us 5 and ten watters. you could get most of a message through, but it took a lt of the fun out of it. Was the AGC on? 73 de Jim, N2EY Part of the equation here is the receiver, as Jim N2EY was bringing up. A lot of folks don't understand that actual bandwidth and apparant bandwith as determined by a receiver are not the same in most cases. Also I really don't see the problem, why did you just sit there? Were you all rock bound or what? Move frequency, were not channelized, yet. That isn't my point, Dan. That wasn't a good signal W1AW was putting out, and it was making a mess out of the local neighborhood. Usually PSK and OOK Morse get along just fine. My point is that by coming out with a ratty signal, W1AW was doing what so many hams were complaining about K1MAN does. Fire it up, and too bad for the rest of you. That and wondering what a CW signal Bandwidth was in the first place. - Mike KB3EIA - |
Mike Coslo wrote in message ...
That isn't my point, Dan. That wasn't a good signal W1AW was putting out, and it was making a mess out of the local neighborhood. Usually PSK and OOK Morse get along just fine. My point is that by coming out with a ratty signal, W1AW was doing what so many hams were complaining about K1MAN does. Fire it up, and too bad for the rest of you. That and wondering what a CW signal Bandwidth was in the first place. - Mike KB3EIA - Mike, Mike, my boy, you just don't understand. The ARRL is kind of like that "Home on the Range" song... where never is heard a discouraging word, and the skies are not cloudy all day. Don't be sayin nuttin bad bout the ARRL, nor their flagship broadcast station W1AW. You'll get the wrath of the Old Man himself when you get up to the Pearly Gates. |
Someone wrote;
That and wondering what a CW signal Bandwidth was in the first place. ------------------------ From the ARRL License Manual 1976: CW Bandwidth = wpm X 4 "With proper shaping, the necessary keying bandwidth is equal to 4 times the speed in words per minute for International Morse Code; e.g. at 25 words per minute, the bandwidth is approximately 100 cycles. e.g., 40 WPM = approximately 160 Hz" -- 73 From The Wilderness Keyboard |
"Keyboard In The Wilderness" wrote in message news:JhiKb.46924$m83.10369@fed1read01...
Someone wrote; That and wondering what a CW signal Bandwidth was in the first place. ------------------------ From the ARRL License Manual 1976: CW Bandwidth = wpm X 4 "With proper shaping, the necessary keying bandwidth is equal to 4 times the speed in words per minute for International Morse Code; e.g. at 25 words per minute, the bandwidth is approximately 100 cycles. e.g., 40 WPM = approximately 160 Hz" Does the ARRL License Manual of 1976 address Farnsworth code and bandwidth? |
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In article , Mike Coslo writes:
That wasn't a good signal W1AW was putting out, and it was making a mess out of the local neighborhood. Are you sure the W1AW signal was dirty? An overloaded receiver or soundcard will do exaclty what you describe. That doesn't mean it's impossible that W1AW had a problem, just that all things need to be checked out. Have you listened to W1AW since then? Usually PSK and OOK Morse get along just fine. Depends on who's doing what. 3579 used to be a popular "glowbug" frequency for Morse folks using simple rigs and a colorburst crystal. Then the freq was taken over by PSK-31 due to the popularity of the "Warbler". My point is that by coming out with a ratty signal, W1AW was doing what so many hams were complaining about K1MAN does. Fire it up, and too bad for the rest of you. W1AW transmits bulletins and code practice on a published schedule, and is on every HF amateur band simultaneously. Been doing that for almost 70 years now. However, the signal should be clean. Didja email them? Even that "professional" Harris stuff can go wacko. 73 de Jim, N2EY That and wondering what a CW signal Bandwidth was in the first place. |
"Brian" wrote in message om... "Keyboard In The Wilderness" wrote in message news:JhiKb.46924$m83.10369@fed1read01... Someone wrote; That and wondering what a CW signal Bandwidth was in the first place. ------------------------ From the ARRL License Manual 1976: CW Bandwidth = wpm X 4 "With proper shaping, the necessary keying bandwidth is equal to 4 times the speed in words per minute for International Morse Code; e.g. at 25 words per minute, the bandwidth is approximately 100 cycles. e.g., 40 WPM = approximately 160 Hz" Does the ARRL License Manual of 1976 address Farnsworth code and bandwidth? The Farnsworth approach isn't even used for faster code speeds like 40wpm so it is a moot point. However the calculation method would be to use the character speed as the parameter in the calculation not the "effective word speed" that is created by increasing the space between characters. Dee D. Flint, N8UZE |
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