[digitalradio] Re: Hey, I'm famous! PSK31 Article on ARRLWeb
Yes, well done Frank, Andy K3UK --- In digitalradio@yahoogroups.com, Sholto Fisher [EMAIL PROTECTED] wrote: Frank, I read your article this morning on the ARRL site. Good job! I especially liked the Bonus Tip - try 30m :) 73, Sholto KE7HPV. Tooner wrote: Hello all, You've seen it here first (files, psk31_tips.pdf) and now live on ARRLWeb News: http://www.arrl.org/news/features/2008/03/11/10007 If you have any good articles that you'd like to see in lights, ARRL will pay to post them. 73. Frank K2NCC htpp://evokefrank.googlepages.com
[digitalradio] 10 Tips for the PSK31 Digital Mode
http://www.arrl.org/news/features/2008/03/11/10007?nc=1 10 Tips for the PSK31 Digital Mode By Frank Ravenswood, K2NCC [EMAIL PROTECTED] March 11, 2008 There's more to going over the waterfall than just having a good barrel. An example of a Waterfall display. [photo by Frank Ravenswood, K2NCC] Use the center of your waterfall (see definitions of italicized terms below) display. Testing will show that your transmit (TX) and receive (RX) will be strongest there. Don’t blindly use a 1000 Hz tone or strictly follow the VFO “set it and forget it” concept. You can easily lose 20% or more of your power on each edge of your passband. Passband centering of the signal will give the best results of both RX and TX. There's no need to have the waterfall streaking bright red. Set your rig's volume to a low level (less than 25% of maximum) and adjust your waterfall and sound card levels for good contrast. Do not overdrive your sound card! Get the background noise and the transmit trace well defined and separate. Keep in mind that how your waterfall looks does not impact decoding, but it is harder to work it if you can’t see it. Use UPPER CASE characters sparingly. Lower case text in PSK31 varicode transmits fewer bits of data. You'll increase transmit speed and improve the likelihood of proper decoding on the other end by using lower case text as much as possible. (For example, the difference between a lowercase “e” (11) and an uppercase “E” (1110111) is three times more bits.) Enable your RF attenuation and increase the volume. This can help keep a strong signal from wiping out the weaker ones. Attenuation will probably be around 20 dB, but by dropping the noise level, the signal readability may improve. AGC (Automatic Gain Control) does nothing for a weak signal; it only levels the louder ones. Use your digital mode’s software, or a program like Spectrogram, to see what your noise level is with the radio off. This will give you an idea of how “clean” your sound card is. Typically, onboard (built-in) sound hardware (as found in most “mainstream” computers like Dell or HP) does not have a signal-to-noise ratio as good as an inexpensive (less than $50) separate sound card. When purchasing a sound card, look for one with a signal-to-noise ratio over 100 dBA. [A-weighted decibels; a scale of sound “loudness’ used in acoustics that simulates the response of human hearing. — Ed.] [Many onboard sound interfaces, while not optimum for high fidelity stereo sound, perform well for many amateur applications. For a technical review of various sound cards see J. Taylor, K1RFD, “Computer Sound Cards for Amateur Radio,” QST, May 2007, pp 63 — 70. — Ed.] Consider dual monitors (most modern video cards have two jacks). This allows you to have the waterfall or spectrum display on one screen and your logger, text window, etc on the other. It makes a huge difference in speed and ease-of-use when you don't have to swap between screens or use smaller windows for your contact. When transmitting, keep your ALC reading as close to zero as possible. This will help keep your signal clean and your IMD at an acceptable level (-20 dB or better is ideal). Your power output will drop, but there's no need to overload the transmit level. PSK31 uses an 80% duty cycle. Even with a full duty cycle rig, it still needs to dissipate heat! Besides, 20 W more makes little difference. Output of around 50 W is enough to work the world, and your fellow operators will appreciate the courtesy. Also be sure your voice processor is not enabled when using digital modes. Ask for an RSQ (readability, strength, quality) report. When in a contact, send just a tone and ask for your IMD and a report on how your trace looks. This will give you a better idea of what adjustments may be needed. There are hundreds of digital modes. To get started or to learn more about the most common ones, refer to the list of digital mode references at the end of this article. Bonus Tip: Try 30 meters PSK31. It’s a robust band, offering the best of 20 meters and 40 meters. Only digital modes and CW are permitted and contesting is not allowed. Be sure to operate within your privileges. PSK31 can typically be found around 10.140 MHz. Definitions of Terms: AGC (automatic gain control): The ability to reduce signal strength on-the-fly, giving you more level audio reception on stronger stations. ALC (automatic level control): A voltage adjustment or reading, indicating your transmit signal levels. ALC is designed to control voice and carrier signal levels, not digital modes. Typically for digital modes, if the ALC meter moves, then the microphone gain is too high. Signal-to-noise ratio (S/N): A comparison of the signal levels to the relative noise level. Ideally, a perfect signal would have no noise, but realistically, you’ll want an S/N ratio well within the tolerances of the mode you’re using. PSK31 tolerates about a 10
Re: [digitalradio] 10 Tips for the PSK31 Digital Mode
Enable your RF attenuation and increase the volume. This can help keep a strong signal from wiping out the weaker ones. Attenuation will probably be around 20 dB, but by dropping the noise level, the signal readability may improve. AGC (Automatic Gain Control) does nothing for a weak signal; it only levels the louder ones. This is a fairly stupid advice, and if you follow it you will miss about 50% of the fun. First thing to do of course is make sure THERE ARE NO STRONGER ONES. In the good old days of CW (an ancient digital mode which was heavily used by older generation hams) we used so-called X-tal filters to filter out signals on a different frequency than the one we worked on. This worked perfectly. Since hams started tuning with clicking a mouse instead of turning a frequency dial this became impossible. QSB on a PSK signal can amount to 80 dB, and using (slow) AGC is a must if you want to copy the weak ones. It also helps to pull weak signals out of noise generated in later stages of the RX. Just using an RF attenuator because there is a strong alien signal within your passband is the WRONG weapon against this. Moreover, NO RX IS LINEAR,so it will produce mixing products which will hit your weak signal. if you want to really take advantage of the small bandwidth why add all that bad stuff on the RX side? To make copy more difficult? Come on, with CW there was an operator who did the decoding. You cannot expect a computer to be as efficient as that. So why not help the poor DSP and filter out noise and crap BEFORE it enters your sound card? 73, Rein EA/PA0R/P (sorry to hit on the same nail over and over...) -- http://pa0r.blogspirit.com Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: 10 Tips for the PSK31 Digital Mode
--- In digitalradio@yahoogroups.com, Rein Couperus [EMAIL PROTECTED] wrote: First thing to do of course is make sure THERE ARE NO STRONGER ONES. This can be done various ways. Typically, I use the variable bandwidth tuning and IF shift to avoid strong signals. But, that's rare to need to do so. I am rarely unable to decode a trace, even with a much stronger signal close by. we used so-called X-tal filters to filter out signals... This worked perfectly. Since hams started tuning with clicking a mouse instead of turning a frequency dial this became impossible. I can appreciate the old-school guys. They had to work hard to get where they are. I am using an old rig that has no DSP and would say it does a better job than most modern rigs. However, don't be so bent on mouse-clicks. Evolve or die, I say. I love big knobs as much as the next guy, but I also like to expand my knowledge beyond the box. QSB on a PSK signal can amount to 80 dB, and using (slow) AGC is a must if you want to copy the weak ones. AGC appears to do nothing for weak signals. AGC is for leveling sound but doesn't appear to increase it. Have you ever used AGC and saw a weak signal get stronger? I haven't. When I notch out everything but a weak trace, then turn on the AGC, the trace doesn't intensify, but fades. Another reason I used RF ATT and just bumped up the volume. That way I can see the whole pass band and get very little splatter. But, again, this is on a single rig. Everyone can feel free to send me your radios so that I may conduct further tests! 8) Just using an RF attenuator because there is a strong alien signal within your passband is the WRONG weapon against this. When I use AGC, it gives more to the stronger signals. Unless I'm working that strong signal, I leave AGC off. When I use RF ATT, it balances all the signals out to a softer level. When I work a very weak station, I leave RF ATT off. I have reconsidered the constant use of my RF ATT. I've done further experimenting since this article (almost two months old) and found that there are times that a very weak signal fades right off the waterfall when I use RF ATT. But it's nearly always a TX that I can't copy very well anyway, so I think the benefits could swing either way. Moreover, NO RX IS LINEAR, so it will produce mixing products which will hit your weak signal. Keep in mind I'm a new ham, with little technical expertise in this hobby beyond my two years of study and HF operation. I don't always know why something does what it does, but experience and the ability to recreate results is what drives my proclamations. I'm always willing to be educated, but I may squirm a bit until I get it. ... if you want to really take advantage of the small bandwidth why add all that bad stuff on the RX side? By all that bad stuff, do you mean the RF ATT and AGC recommendations? Hardly seems to be as massive an issue as suggested. RF ATT may need more consideration, true, yet it still works nicely in 90% of my traces, so I think little harm is done. To make copy more difficult? That does not seem to be a major case here. If you're in a room full of people, all speaking very loudly, you might not be able to hear the guy right next to you. Drop the room (and the guy's) volume down 40db, and imagine how clearly you will hear him then. I don't think adding AGC will increase his volume, but of you put walls around him (notching) or eliminate 80% of the voices (VBT), it'll be even better. Come on, with CW there was an operator who did the decoding. You cannot expect a computer to be as efficient as that. This seems only vaguely related, so I'm guessing you're a hard-core CW fan? Your rig, if younger than a decade or so, IS a computer. So why not help the poor DSP and filter out noise That's assuming one has a DSP filter. I use IF Shift, Notch and VBT. Again, on a different rig, I might get different results. This is a fairly stupid advice, and if you follow it you will miss about 50% of the fun. 'Fairly stupid advice' is a trolling expression and not the best way to get a diplomatic response. I doubt 50% is a fair number either, but anyway. I welcome corrections and will change my mind based upon new information. I appreciate your advice and hope to hear more. You appear to be more technically savvy with the radios, so maybe you'll offer some sort of test for us to try. I'd love to compare numbers and to learn more. Keep in mind, the article isn't meant for as a bible of PSK. It's just sharing what I've learned in the last year, which is constantly evolving. The majority of the article still stands on it's merit. Frank, K2NCC
Re: [digitalradio] Re: 10 Tips for the PSK31 Digital Mode
There is no difference between an RF gain control and AGC. AGC is just Auotmatic Gain control instead of manual gain control. The only way to copy a weak signal adjacent to a strong one is to prevent the strong signal from affecting the AGC, and the only way to do that is by using a narrrow filter or notch filter (at IF, not audio) to attenuate the strong signal. You can use a wide (SSB) filter to see all the stations in the passband, and then use Passband Tuning or IF Shift, or a narrow filter (at IF, not audio!) to narrow in on the station you want to work if it is one of the weaker ones. You do not need to do anything for the strong signal unless it is overloading your front end and then you can switch in attenuation and switch it out again when you are finished. Many people have experienced a weak PSK31 signal disappearing or waterfall darkening when a strong signal comes on. This is because the strong signal is reducing the gain (and therefore the noise background), just the same as if you manually reduced the gain, and generally the only cure for this is using narrow filtering. Some receivers, designed specifically for PSK31, such as our latest PSK-20, do not use AGC, but distribute gain in such as way that it can copy weak signals adjacent to strong ones, without distorting the last IF stage or detector, but few transceivers can do this. A dual-loop AGC system may help and some high-end transceivers have this. 73, Skip KH6TY
RE: [digitalradio] Re: 10 Tips for the PSK31 Digital Mode
One more consideration is AGC recovery time. Slow AGC and static crashes are not a good combo in many of the digital modes. No AGC or Fast AGC will make a difference in that situation. This may not apply to PSK-31 as much as more complex digital modes, but a point worth considering. DSP filtering of signals above and below the signal you are trying to copy are also a great help; if your rig will allow that narrow of a passband. David KD4NUE -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of kh6ty Sent: Wednesday, March 12, 2008 4:13 PM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Re: 10 Tips for the PSK31 Digital Mode There is no difference between an RF gain control and AGC. AGC is just Auotmatic Gain control instead of manual gain control. The only way to copy a weak signal adjacent to a strong one is to prevent the strong signal from affecting the AGC, and the only way to do that is by using a narrrow filter or notch filter (at IF, not audio) to attenuate the strong signal. You can use a wide (SSB) filter to see all the stations in the passband, and then use Passband Tuning or IF Shift, or a narrow filter (at IF, not audio!) to narrow in on the station you want to work if it is one of the weaker ones. You do not need to do anything for the strong signal unless it is overloading your front end and then you can switch in attenuation and switch it out again when you are finished. Many people have experienced a weak PSK31 signal disappearing or waterfall darkening when a strong signal comes on. This is because the strong signal is reducing the gain (and therefore the noise background), just the same as if you manually reduced the gain, and generally the only cure for this is using narrow filtering. Some receivers, designed specifically for PSK31, such as our latest PSK-20, do not use AGC, but distribute gain in such as way that it can copy weak signals adjacent to strong ones, without distorting the last IF stage or detector, but few transceivers can do this. A dual-loop AGC system may help and some high-end transceivers have this. 73, Skip KH6TY
Re: [digitalradio] Re: 10 Tips for the PSK31 Digital Mode
Skip - Original Message - From: David Little [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Wednesday, March 12, 2008 4:25 PM Subject: RE: [digitalradio] Re: 10 Tips for the PSK31 Digital Mode One more consideration is AGC recovery time. Slow AGC and static crashes are not a good combo in many of the digital modes. No AGC or Fast AGC will make a difference in that situation. This may not apply to PSK-31 as much as more complex digital modes, but a point worth considering. DSP filtering of signals above and below the signal you are trying to copy are also a great help; if your rig will allow that narrow of a passband. David KD4NUE You never want to use Fast AGC on PSK31, because the receiver will attempt to follow the PSK31 signal and cause distortion. Always use the slowest AGC setting you have, or no AGC at all. BTW, to accurately measure IMD, reduce your RF gain until the IMD reading stops falling and report that as the IMD reading. The reason for this is that the receiver must amplify linearly for PSK31 and if a signal is strong enough to distort the RF amplifier or IF amplifers, you get a false (usually poorer) IMD reading. Also, IMD is the measure of the first set of unwanted sidebands and if the signal to noise ratio is poor, the software will be measuring the noise at the same point as unwanted sidebands and reporting a poor IMD. It is better just to look for unwanted sidebands and report if you see any or not. The caveat is that the unwanted sidebands may be so far down in the noise you cannot see them, even though they are there, but as far as you, or a station with the same reception as yours, it does not matter, as the unwanted sidebands are not going to bother an adjacent station. Still, the best practice is to always transmit with a linear, clean, signal so your unwanted sidebands do not QRM any adjacent station, either near to you or somewhere else 73, Skip KH6TY .
Re: [digitalradio] Re: 10 Tips for the PSK31 Digital Mode
kh6ty wrote: A dual-loop AGC system may help and some high-end transceivers have this. 73, Skip KH6TY Dual loop AGC is a two sided sword. I have come to find better, and not necessarily easier, to have low noise, low gain stages before the filters that will not overload so easily. The TS-520 I used in another contest in 1978 was deafened when a local station, 5 km away turned is beam towards Japan...and over me, on 15 meters. There was nothing I could do, again, in the middle of the contest, so I had to go back to 20, the next open band. His ground wave was desensing my front end so badly that it became useless to attempt to work the weak japanese signals while RF gain was pumped with his audio. And the attenuator did not solve that issue at all. Those are things you learn the hard way while contesting. Are you going to ask a competitor in the heat of a contest to lower his power because he is deafening you? 73, Jose
Re: [digitalradio] 10 Tips for the PSK31 Digital Mode
My comments were meant to be a bit provocative I am reacting to this subject now for the umpteenth time, and still people get the advice to use 2.5 kHz bandfilters on a 31 Hz wide signal. That way you will not get optimum performance from your RX. The ONLY point I wanted to make is that if you use a proper filter, matched to the mode, you will have a lot more fun and hear/work many more stations. The tradeoff is that you have to use a round knob instead of a computer mouse to tune the signal. And as this is the digital RADIO group I thought that a warning was appropriate :) Maybe I should advice to reread the articles about proper RX design by Ullrich Rhode in QST, maybe around 1970... that also tells you how large signals in your rx produce mixing products and desensing, and also why a properly designed AGC system will actually work. I am camping in EA at the moment, and 2 times during the day the pskmail servers I use are slowly QSB'ing from S0 - 20 dB to S9. The AGC easily fixes that (300 HZ filter on a FT897D, using PSK250). The APRS backbone on 10.149 kHz which would be fully inside the 2.5 kHz passband would make all operation impossible without a filter... (These guys relay 300 Bd APRS packets from 2meters to HF by the way, and I could read a book in the light of lamp connected to my antenna... :) The 'noise and crap' I was referring to is the stuff your RX adds to the signal by using non-linear circuits, before giving it to your SOUNDCARD DSP. So even if your rig doesn't have one, your computer does... And yes, I have visited several hams who could hear MORE than twice the stations after switching from a 2.5 kHz (panoramic) to 250 Hz filter. To answer some questions from Jose... Yes, I have worked in M/M and M/2 HP environments. Check CT9L, TS7N (2003), 5A7A(2005), ED8A(last November), all top 3 WW operations. For such activities we use K2's most of the time. And bandfilters on every TRX. And yes, at home I am using a TenTec ORION (100Hz for PSK31). 73, Rein EA/PA0R/P -Ursprüngliche Nachricht- Von: digitalradio@yahoogroups.com Gesendet: 12.03.08 21:36:18 An: digitalradio@yahoogroups.com Betreff: Re: [digitalradio] 10 Tips for the PSK31 Digital Mode Enable your RF attenuation and increase the volume. This can help keep a strong signal from wiping out the weaker ones. The same that was recommended to work CW ages ago, using manual gain control and no AGC. Attenuation will probably be around 20 dB, but by dropping the noise level, the signal readability may improve. 20 dB MAY be too much...but it may help better than doing nothing. AGC (Automatic Gain Control) does nothing for a weak signal; it only levels the louder ones. Rein Couperus wrote: This is a fairly stupid advice, and if you follow it you will miss about 50% of the fun. I am afraid that such a phrase is too strong... First thing to do of course is make sure THERE ARE NO STRONGER ONES. How should that be physically accomplished ? Does that include the neighbor in the block, or is PSK meant only to be operated from desert places? And not only PSK, but include there CW, RTTY, SSB, whatever comes to your front end. Here, on 40 meters, things can get quite mixed up around 7070 (happily, there is no more Radio Tirana on 7065). In the good old days of CW (an ancient digital mode which was heavily used by older generation hams) we used so-called X-tal filters to filter out signals on a different frequency than the one we worked on. This worked perfectly. Since hams started tuning with clicking a mouse instead of turning a frequency dial this became impossible. No, there are still people who use those filters. I do ocassionally. All exagerations may entail surprises... QSB on a PSK signal can amount to 80 dB, and using (slow) AGC is a must if you want to copy the weak ones. If you do that, you will force the weaker signals to be incopiable. From THERE seems to arise your request to have only feeble signals near your passband. A good radio should have a larger dynamic margin, say, 100 dB. AGC should be able to level signals up to 120 dB... if the front end is not overloaded. A polyphase filter RX, using a quadrature sampling detector can achieve that, without AGC at all. It also helps to pull weak signals out of noise generated in later stages of the RX. Just using an RF attenuator because there is a strong alien signal within your passband is the WRONG weapon against this. Not necessarily so. Have you ever operated a multi operator multi transmitter station ? Maybe it looks against common sense, but that way you can achieve that your front end does not get overloaded. No stages on a linear receiver shoul be allowed to overload, ever. That was a fact when operating 80 meters in the ARRL International contest in 1999. The operator on 40 was using the BIG
[digitalradio] Re: 10 Tips for the PSK31 Digital Mode
--- In digitalradio@yahoogroups.com, Rein Couperus [EMAIL PROTECTED] wrote: ... I have visited several hams who could hear MORE than twice the stations after switching from a 2.5 kHz (panoramic) to 250 Hz filter. While on the subject of filters, my current setup allows me to narrow my SSB signal down to 500 Hz. Maxed out, the pass band is about 2.7 kHz, (3.6 on CW Wide.) I have no optional filters installed, so I've been thinking of adding one or two (I think YK-88CN and YG-455CN). I like the idea of having a narrower VBT of 250 Hz (-6 dB) to 500 Hz (-60 dB) with the YG-455CN filter. BUT, it seems that's for the CW Narrow mode switch position. Will that do anything all all for SSB? It's a Kenwood hybrid (TS-830S). If a CW Narrow filter isn't going to help my digital modes RX, then is there some other filter I can add that will give the improvement you've stated above? I've heard of a YG-88S, but don't see any mention of it in the manual. Looks like http://www.qth.com/inrad/ has some in stock. Any suggestions? Well, other than buy a new radio! 8) Frank, K2NCC
Re: [digitalradio] 10 Tips for the PSK31 Digital Mode
Rein Couperus wrote: My comments were meant to be a bit provocative He! Well, you knew what you were doing The ONLY point I wanted to make is that if you use a proper filter, matched to the mode, you will have a lot more fun and hear/work many more stations. The tradeoff is that you have to use a round knob instead of a computer mouse to tune the signal. And as this is the digital RADIO group I thought that a warning was appropriate :) That is a tradeoff...selectivity for convenience...sadly, not everybody is aware of that FACT. Maybe I should advice to reread the articles about proper RX design by Ulrich Rhode in QST, maybe around 1970... that also tells you how large signals in your rx produce mixing products and desensing, and also why a properly designed AGC system will actually work. And Ham Radio in the 80's (there is a VERY GOOD article on digital military communications receivers in april 1985). Also I would recommend his book Communications Receivers. I am lucky I have been able to get a Ham Radio collection, a top notch magazine, indeed. I am camping in EA at the moment, and 2 times during the day the pskmail servers I use are slowly QSB'ing from S0 - 20 dB to S9. The AGC easily fixes that (300 HZ filter on a FT897D, using PSK250). The APRS backbone on 10.149 kHz which would be fully inside the 2.5 kHz passband would make all operation impossible without a filter... (These guys relay 300 Bd APRS packets from 2meters to HF by the way, and I could read a book in the light of lamp connected to my antenna... :) The 'noise and crap' I was referring to is the stuff your RX adds to the signal by using non-linear circuits, before giving it to your SOUNDCARD DSP. So even if your rig doesn't have one, your computer does... And yes, I have visited several hams who could hear MORE than twice the stations after switching from a 2.5 kHz (panoramic) to 250 Hz filter. To answer some questions from Jose... Yes, I have worked in M/M and M/2 HP environments. Check CT9L, TS7N (2003), 5A7A(2005), ED8A(last November), all top 3 WW operations. For such activities we use K2's most of the time. And bandfilters on every TRX. And yes, at home I am using a TenTec ORION (100Hz for PSK31). OK, those seem to be better radios than the older ones I mentioned, which is not surprising at all. Nevertheless, it is funny to experience what at times a toggle switch and two resistors do with not so top notch stuff. If you are living part time in Spain, I assume you understand spanish. So, Calderon said: En este mundo traidor, nada es verdad ni es mentira, todo será del color del cristal con que se mira. So, our experiences are certainly tainted (among other things) by the radios we use. I have used quite a few and not owned all of them...so far, I have not tried a K2 or an Orion... 73, Jose, CO2JA Linux User 91155
[digitalradio] PropNet and JT65 frequencies
Hi all, I am in communication with Ev, W2EV with regards to the current PropNet JT65 contention issue and he has asked what my proposal would be regarding frequency coordination. PropNet and JT65 both require international potential so this means they both need to be in the small region of 10.140 - 10.150 MHz (carrier). Currently the frequencies are:- From http://www.propnet.org/frequency_grid.html 10.138.9 (USB vfo) with offsets from 1300Hz to 1600Hz depending on geographical location. From http://hflink.com/jt65/ the JT65 frequency is: The JT65A frequency 30metres is 10139.0 kHz USB VFO JT65 has a suggested audio frequency center of 1360Hz with the sync tone being at 1270 (approx) and the upper edge is around 1450Hz. I am aware that the area from 10.140 (carrier) to approximately 10.140.2 (carrier) is utilized by the QRSS folks and they would probably not like anything moving down into their segment. Does anyone in the 30MDG or Digital Radio group have an opinion on where PropNet could find a home on 30m without causing a problem? I am thinking they either need to go back to where they were or move up to something like 10.141.2 (USB vfo). But would this impact PSK31 DX? I know the PropNet vs JT65 thing is not at the top of many people's list but it's making JT65 impossible on 30m right now. 73, Sholto KE7HPV.
Re: [digitalradio] PropNet and JT65 frequencies
I recommend that they move even higher in the 140-150 segment, PSK runs around 141 to 143, RTTY 142 to 145 so I guess if they want to be nice they could even move higher, what caused them to move down the band? Ron W4LDE Sholto Fisher wrote: Hi all, I am in communication with Ev, W2EV with regards to the current PropNet JT65 contention issue and he has asked what my proposal would be regarding frequency coordination. PropNet and JT65 both require international potential so this means they both need to be in the small region of 10.140 - 10.150 MHz (carrier). Currently the frequencies are:- From http://www.propnet.org/frequency_grid.html 10.138.9 (USB vfo) with offsets from 1300Hz to 1600Hz depending on geographical location. From http://hflink.com/jt65/ the JT65 frequency is: The JT65A frequency 30metres is 10139.0 kHz USB VFO JT65 has a suggested audio frequency center of 1360Hz with the sync tone being at 1270 (approx) and the upper edge is around 1450Hz. I am aware that the area from 10.140 (carrier) to approximately 10.140.2 (carrier) is utilized by the QRSS folks and they would probably not like anything moving down into their segment. Does anyone in the 30MDG or Digital Radio group have an opinion on where PropNet could find a home on 30m without causing a problem? I am thinking they either need to go back to where they were or move up to something like 10.141.2 (USB vfo). But would this impact PSK31 DX? I know the PropNet vs JT65 thing is not at the top of many people's list but it's making JT65 impossible on 30m right now. 73, Sholto KE7HPV. Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links
Re: [digitalradio] PropNet and JT65 frequencies
Ron, I asked Ev the same question and his reply was: Hi Sholto, During DXpeditions, it seems that split frequency operators were telling people to listen in the same segment that PropNET was operating within. Trying to be good band co-occupants, we studied DX spots and determined that this was, by far, the least spotted segment in the PSK31 portion of the band 73, Sholto KE7HPV. W4LDE-Ron wrote: I recommend that they move even higher in the 140-150 segment, PSK runs around 141 to 143, RTTY 142 to 145 so I guess if they want to be nice they could even move higher, what caused them to move down the band? Ron W4LDE
Re: [digitalradio] Re: 10 Tips for the PSK31 Digital Mode
Frank, 500 Hz is already a nice improvement with respect to 2.5 kHz.. While on the subject of filters, my current setup allows me to narrow my SSB signal down to 500 Hz. Maxed out, the pass band is about 2.7 kHz, (3.6 on CW Wide.) I have no optional filters installed, so I've been thinking of adding one or two (I think YK-88CN and YG-455CN). I like the idea of having a narrower VBT of 250 Hz (-6 dB) to 500 Hz (-60 dB) with the YG-455CN filter. BUT, it seems that's for the CW Narrow mode switch position. Will that do anything all all for SSB? It depends... I don't know the 830 well enough to say. Anyway, the trick normally is to TX in SSB mode and RX in CW mode, and compensate any frequency difference with the RIT control or the CAT remote control. Most transceivers have this cross-mode possibility. Some other transceivers have an RTTY mode which can use a narrow filter, although that is mostly limited to min. 500 Hz. And some can receive RTTY but then only send FSK. In this respect the FT897D is ideal, it allows the use of all filters in all modes. (Which should be the normal case really, why should this be limited? It is set by the software anyway...). I have had bad luck at PI4TUE with the IC756 for instance. I bought a CW filter and found out that the set would not work cross-mode, not even from the memory bank! There the saviour was to shift the 'sweet spot' to 1500 Hz and use the internal DSP with 300 Hz BW. This happens inside the AGC loop, so it is o.k. If your set does not offer one of these possibilities and you don't want to consider buying a new radio you could always buy a K2 kit, which is a box containing 1300 parts. It only needs a bit of soldering, and is ideal for all digital modes :) 73, Rein EA/PA0R/P It's a Kenwood hybrid (TS-830S). If a CW Narrow filter isn't going to help my digital modes RX, then is there some other filter I can add that will give the improvement you've stated above? I've heard of a YG-88S, but don't see any mention of it in the manual. Looks like http://www.qth.com/inrad/ has some in stock. Any suggestions? Well, other than buy a new radio! 8) Frank, K2NCC -- http://pa0r.blogspirit.com Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] PropNet and JT65 frequencies
Warning: DXpeditions have a lifetime of average 1 week, they send there 'clients' where they find a quiet spot. The next one will find you. 73, Rein EA/PA0R/P Hi Sholto, During DXpeditions, it seems that split frequency operators were telling people to listen in the same segment that PropNET was operating within. Trying to be good band co-occupants, we studied DX spots and determined that this was, by far, the least spotted segment in the PSK31 portion of the band -- http://pa0r.blogspirit.com Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Does K2 work OK for wider digital modes?
With some of the recent comments about filtering and the use of the Elecraft K2, I was wondering if these rigs are OK for the wider digital modes that can exceed 2000 Hz. Also, do you find that most rigs with no TCXO (such as the K2), will work OK for the digital modes, including MFSK16 and similar modes that require very close tolerance on frequency stability? This was one of the things that prompted me to buy the ICOM IC-7000 for my wife, since the TCXO is built in and it has something around 0.5 ppm frequency stability. This is better than some other rigs, such as the Ten Tec Argonaut V which has TCXO, but not that that accuracy. I did not find any problem in using it, but I suspect that this mostly becomes an issue if you are in an environment with changing ambient temperatures, such as outside, field day, emergency use, etc. 73, Rick, KV9U Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] TCXO for digital modes
Also, do you find that most rigs with no TCXO (such as the K2), will work OK for the digital modes, including MFSK16 and similar modes that require very close tolerance on frequency stability? Both rigs that I have been using for digital modes, both wide and narrow do not have TCXO installed, but they are able to maintain a very tight tolerance (usually less than 20hz) over an extended period. The rigs are Kenwood's, a TS850 and a TS480. The TS850 is out about 20hz on the dial, on all bands, but that is a calibration issue. even with extended operating and heavy duty cycles. with the resulting heat rise, does not affect these rigs. John VE5MU
RE: [digitalradio] PropNet and JT65 frequencies
I asked Ev some of the same questions with the same type of answers. Propnet on 20m is tucked away on 14097, so being a narrow mode a good place for them would be just under 10150. Since they are not involved in QSO's and are simply transmitting beacons that would be a good place for them. Slightly different subject , but why are there so many propnet stations on 30M, and so few on 20 and 40? John VE5MU From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of W4LDE-Ron Sent: Wednesday, March 12, 2008 4:53 PM To: digitalradio@yahoogroups.com Cc: [EMAIL PROTECTED] Subject: Re: [digitalradio] PropNet and JT65 frequencies I recommend that they move even higher in the 140-150 segment, PSK runs around 141 to 143, RTTY 142 to 145 so I guess if they want to be nice they could even move higher, what caused them to move down the band? Ron W4LDE Sholto Fisher wrote: Hi all, I am in communication with Ev, W2EV with regards to the current PropNet JT65 contention issue and he has asked what my proposal would be regarding frequency coordination. PropNet and JT65 both require international potential so this means they both need to be in the small region of 10.140 - 10.150 MHz (carrier). Currently the frequencies are:- From http://www.propnet.org/frequency_grid.html 10.138.9 (USB vfo) with offsets from 1300Hz to 1600Hz depending on geographical location. From http://hflink.com/jt65/ the JT65 frequency is: The JT65A frequency 30metres is 10139.0 kHz USB VFO JT65 has a suggested audio frequency center of 1360Hz with the sync tone being at 1270 (approx) and the upper edge is around 1450Hz. I am aware that the area from 10.140 (carrier) to approximately 10.140.2 (carrier) is utilized by the QRSS folks and they would probably not like anything moving down into their segment. Does anyone in the 30MDG or Digital Radio group have an opinion on where PropNet could find a home on 30m without causing a problem? I am thinking they either need to go back to where they were or move up to something like 10.141.2 (USB vfo). But would this impact PSK31 DX? I know the PropNet vs JT65 thing is not at the top of many people's list but it's making JT65 impossible on 30m right now. 73, Sholto KE7HPV. Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Check our other Yahoo Groups http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/themixwgroup Yahoo! Groups Links
[digitalradio] MEPT_JT sked page now active
By request, I have added a MEPT SKED page at http://www.obriensweb.com/sked click on MEPT and join the experimenting... with 6hz wide signals ! Andy k3UK -- In digitalradio@yahoogroups.com, Andrew O'Brien [EMAIL PROTECTED] wrote: From:Joe Taylor, K1JT Subject: New software for MEPT Date:March 9, 2008 About two weeks ago Murray Greenman, ZL1BPU, wrote to me suggesting that I consider adding a mode optimized for MEPT to my software package WSJT. I expressed interest in the idea, and we exchanged a few emails about possible specifications. Then I sat down and wrote out some detailed specs, and finally got busy and wrote a bare-bones program implementing the new mode. I write now to let you know that an early realease of the program is ready for testing. The program's provisional name is MEPT_JT. At present it is a stand-alone executable, independent of WSJT. It is functional for both transmitting and receiving, but it has no frills -- no graphics, no GUI, etc. It is executed from a Windows command prompt. Like WSJT, MEPT_JT uses a computer sound card to generate audio tones to modulate an SSB transceiver operating on the upper sideband. In receive mode the sound card digitizes audio from the transceiver. The program scans a 200 Hz passband (the QRSS window) looking for MEPT_JT signals, and decodes them. Basic operating instructions for the initial release can be found in the file MEPT_Instructions.TXT at http://physics.princeton.edu/pulsar/K1JT/MEPT_Instructions.TXT . The basic specifications of MEPT_JT are as follows: 1. Transmitted message: callsign + 4-character-locator + dBm Example: K1JT FN20 30 2. Message length after lossless compression: 50 bits (28 bits for callsign, 15 for locator, 7 for power level). 3. Long-constraint convolutional FEC with K=32, r=1/2. 4. Number of channel symbols: nsym = (50+31)*2 = 162. 5. Modulation: continuous phase 4-FSK. 6. Synchronization: 162-bit pseudo-random sync vector. 7. Data structure: each channel symbol conveys one sync bit and one data bit. 8. Keying rate: 12000/8192 = 1.46 baud. 9. Duration of transmission: 162*8192/12000 = 110.6 s. 10. Transmissions start two seconds into an even UTC minute: i.e., at hh:00:02, hh:02:02, ... 10. Occupied bandwidth: 6 Hz 11. Minimum S/N for reception: around -27 dB on the WSJT scale (2500 Hz reference bandwidth). You can run Argo, Spectran, or WSJT at the same time as MEPT_JT, in order to provide a waterfall spectral display. In normal operation MEPT_JT displays information every two minutes and is silent otherwise. In transmit mode in prints a single line when a new transmission starts. In receive mode the program looks for detectable MEPT_JT signals in a 200 Hz passband, decodes them, and displays the results. If nothing is decoded, nothing will be printed. Like JT65, MEPT_JT includes very efficient data compression and strong forward error correction. Received messages are nearly always exactly the same as the transmitted message, or else they are left blank. Version 0.2 of MEPT_JT is functional -- and extremely sensitive -- but the user interface is rough in many places. Suggestions for improvements will be most welcome! Can anyone come up with a better name for the program? Please email all suggestions to k1jt at arrl dot net. -- 73, Joe, K1JT
Re: [digitalradio] PropNet and JT65 frequencies
That would probably QRM the HF APRS channel, which is around 10.1495 (10.1515 LSB, 2100-2300 Hz AF). Unfortunately, it's almost impossible to do any kind of frequency coordination on 30m. It's been my experience that there isn't one single Hz of bandwidth that is not occupied by CW, gigawatt RTTY stations, beacons, winlids, or other operation. -Joe, N8FQ On Wed, 12 Mar 2008 18:55:46 -0600 John Bradley [EMAIL PROTECTED] wrote: I asked Ev some of the same questions with the same type of answers. Propnet on 20m is tucked away on 14097, so being a narrow mode a good place for them would be just under 10150. Since they are not involved in QSO's and are simply transmitting beacons that would be a good place for them.
Re: [digitalradio] PropNet and JT65 frequencies
How about moving the JT65 stations, the freq was simply one suggested by Bonnie, nothing cast in stone. On Wed, Mar 12, 2008 at 9:34 PM, Joe Veldhuis [EMAIL PROTECTED] wrote: That would probably QRM the HF APRS channel, which is around 10.1495 (10.1515 LSB, 2100-2300 Hz AF). Unfortunately, it's almost impossible to do any kind of frequency coordination on 30m. It's been my experience that there isn't one single Hz of bandwidth that is not occupied by CW, gigawatt RTTY stations, beacons, winlids, or other operation. -Joe, N8FQ On Wed, 12 Mar 2008 18:55:46 -0600 John Bradley [EMAIL PROTECTED] wrote: I asked Ev some of the same questions with the same type of answers. Propnet on 20m is tucked away on 14097, so being a narrow mode a good place for them would be just under 10150. Since they are not involved in QSO's and are simply transmitting beacons that would be a good place for them. -- Andy K3UK www.obriensweb.com (QSL via N2RJ)
Re: [digitalradio] PropNet and JT65 frequencies
Andy, I am ok with this idea too but we have to start somewhere. Ev is being extremely cooperative in looking for a solution/compromise and I have posted a message to the WSJT group asking for their help too. But I am seeing most JT65 and JT2 etc still using the 10.139 frequency so thought maybe it was easier to see how flexible PropNet was and bearing in mind they are the ones who recently moved down. 73, Sholto KE7HPV. Andrew O'Brien wrote: How about moving the JT65 stations, the freq was simply one suggested by Bonnie, nothing cast in stone. On Wed, Mar 12, 2008 at 9:34 PM, Joe Veldhuis [EMAIL PROTECTED] wrote: That would probably QRM the HF APRS channel, which is around 10.1495 (10.1515 LSB, 2100-2300 Hz AF). Unfortunately, it's almost impossible to do any kind of frequency coordination on 30m. It's been my experience that there isn't one single Hz of bandwidth that is not occupied by CW, gigawatt RTTY stations, beacons, winlids, or other operation. -Joe, N8FQ On Wed, 12 Mar 2008 18:55:46 -0600 John Bradley [EMAIL PROTECTED] wrote: I asked Ev some of the same questions with the same type of answers. Propnet on 20m is tucked away on 14097, so being a narrow mode a good place for them would be just under 10150. Since they are not involved in QSO's and are simply transmitting beacons that would be a good place for them.
[digitalradio] Re: PropNet and JT65 frequencies
OK Sholto,. Ev is always very cooperative. Andy. --- In digitalradio@yahoogroups.com, Sholto Fisher [EMAIL PROTECTED] wrote: Andy, I am ok with this idea too but we have to start somewhere. Ev is being extremely cooperative in looking for a solution/compromise and I have posted a message to the WSJT group asking for their help too. But I am seeing most JT65 and JT2 etc still using the 10.139 frequency so thought maybe it was easier to see how flexible PropNet was and bearing in mind they are the ones who recently moved down. 73, Sholto KE7HPV. Andrew O'Brien wrote: How about moving the JT65 stations, the freq was simply one suggested by Bonnie, nothing cast in stone. On Wed, Mar 12, 2008 at 9:34 PM, Joe Veldhuis [EMAIL PROTECTED] wrote: That would probably QRM the HF APRS channel, which is around 10.1495 (10.1515 LSB, 2100-2300 Hz AF). Unfortunately, it's almost impossible to do any kind of frequency coordination on 30m. It's been my experience that there isn't one single Hz of bandwidth that is not occupied by CW, gigawatt RTTY stations, beacons, winlids, or other operation. -Joe, N8FQ On Wed, 12 Mar 2008 18:55:46 -0600 John Bradley [EMAIL PROTECTED] wrote: I asked Ev some of the same questions with the same type of answers. Propnet on 20m is tucked away on 14097, so being a narrow mode a good place for them would be just under 10150. Since they are not involved in QSO's and are simply transmitting beacons that would be a good place for them.
