Re: [digitalradio] Signal on 3850
I am located in the middle of North Carolina, USA --- On Tue, 5/13/08, John Simon [EMAIL PROTECTED] wrote: From: John Simon [EMAIL PROTECTED] Subject: Re: [digitalradio] Signal on 3850 To: digitalradio@yahoogroups.com Date: Tuesday, May 13, 2008, 10:59 PM Ummm, where are you? I can't hear anything here in VK. John de VK2XGJ Stop worrying about Life You'll never get out of it alive - Original Message - From: Ralph Mowery [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Wednesday, May 14, 2008 12:23 PM Subject: [digitalradio] Signal on 3850 A friend told me to lisen on 3850 lsb +- a kc or two. There is some digital type signal there. Does anyone know what it is and where it is comming from. 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 No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 269.23.16/1431 - Release Date: 5/13/2008 7:55 PM 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] Signal on 3850
Ralph, A group of us were beta testing a brand new mode for NBEMS on HF, especially designed to survive extremely high, almost continuous, levels of static (such as follows a hurricane). One station was in Florida, one in Alabama, one in Georgia, and one in South Carolina. We were on 3854, USB, around 1500 Hz tone frequency, so that is probably what you heard, since you are close by. The new mode is called DEX and is expected to be released for NBEMS HF beta testing with this group in about two weeks. 73, Skip KH6TY NBEMS Development Team - Original Message - From: Ralph Mowery To: digitalradio@yahoogroups.com Sent: Wednesday, May 14, 2008 6:17 AM Subject: Re: [digitalradio] Signal on 3850 I am located in the middle of North Carolina, USA --- On Tue, 5/13/08, John Simon [EMAIL PROTECTED] wrote: From: John Simon [EMAIL PROTECTED] Subject: Re: [digitalradio] Signal on 3850 To: digitalradio@yahoogroups.com Date: Tuesday, May 13, 2008, 10:59 PM Ummm, where are you? I can't hear anything here in VK. John de VK2XGJ Stop worrying about Life You'll never get out of it alive - Original Message - From: Ralph Mowery [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Wednesday, May 14, 2008 12:23 PM Subject: [digitalradio] Signal on 3850 A friend told me to lisen on 3850 lsb +- a kc or two. There is some digital type signal there. Does anyone know what it is and where it is comming from. 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 -- No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 269.23.16/1431 - Release Date: 5/13/2008 7:55 PM 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 -- No virus found in this incoming message. Checked by AVG. Version: 7.5.524 / Virus Database: 269.23.16/1430 - Release Date: 5/13/2008 7:31 AM
Re: [digitalradio] Signal on 3850
Ralph Mowery wrote: A friend told me to lisen on 3850 lsb +- a kc or two. There is some digital type signal there. Does anyone know what it is and where it is comming from. I hear it pretty well in upstate SC. Don't know what it is nor where it is coming from. It sounds to me like a 600 hz tone on a double side band suppressed carrier. Lots of static here however. Dean -- W4IHK
Re: [digitalradio] Signal on 3850
The msg has no signature, no Call, no identification whatsoever. That is why I asked the question. John de VK2XGJ Stop worrying about Life You'll never get out of it alive - Original Message - From: Ralph Mowery [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Wednesday, May 14, 2008 8:17 PM Subject: Re: [digitalradio] Signal on 3850 I am located in the middle of North Carolina, USA --- On Tue, 5/13/08, John Simon [EMAIL PROTECTED] wrote: From: John Simon [EMAIL PROTECTED] Subject: Re: [digitalradio] Signal on 3850 To: digitalradio@yahoogroups.com Date: Tuesday, May 13, 2008, 10:59 PM Ummm, where are you? I can't hear anything here in VK. John de VK2XGJ Stop worrying about Life You'll never get out of it alive - Original Message - From: Ralph Mowery [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Wednesday, May 14, 2008 12:23 PM Subject: [digitalradio] Signal on 3850 A friend told me to lisen on 3850 lsb +- a kc or two. There is some digital type signal there. Does anyone know what it is and where it is comming from. 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 No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 269.23.16/1431 - Release Date: 5/13/2008 7:55 PM 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 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 No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 269.23.16/1431 - Release Date: 5/13/2008 7:55 PM
Re: [digitalradio] Signal on 3850
Download Digipan or Ham Radio Deluxe. Then there is also MixW. Use it, tune to the freq, do some fiddling and find out! --- On Tue, 5/13/08, Ralph Mowery [EMAIL PROTECTED] wrote: From: Ralph Mowery [EMAIL PROTECTED] Subject: [digitalradio] Signal on 3850 To: digitalradio@yahoogroups.com Date: Tuesday, May 13, 2008, 7:23 PM A friend told me to lisen on 3850 lsb +- a kc or two. There is some digital type signal there. Does anyone know what it is and where it is comming from.
[digitalradio] Re: Dex 11 , was Signal on 3850
I have decoded Dex 11 and occasionally Dex 16 (with FL-Digi) on that frequency in the evening the past few days. N4UM and N8FQ were testing , they also used Hell and Olivia. On the evening that I listened in, Dex 11 seemed to perform the best. It will be most interesting to see who Dex performs with error correction file exchanges within NBEMS when it is released . Andy K3UK On Tue, May 13, 2008 at 11:28 PM, Dean Craft [EMAIL PROTECTED] wrote: Ralph Mowery wrote: A friend told me to lisen on 3850 lsb +- a kc or two. There is some digital type signal there. Does anyone know what it is and where it is comming from. I hear it pretty well in upstate SC. Don't know what it is nor where it is coming from. It sounds to me like a 600 hz tone on a double side band suppressed carrier. Lots of static here however. Dean -- W4IHK -- Andy K3UK www.obriensweb.com (QSL via N2RJ)
Re: [digitalradio] Signals on 3584 + audio
Hi Rick, FYI, our tests last night indicate that MFSK16 still copies the best at low S/N, but only when there are no static crashes, but DEX16 or DEX11 have much fewer errors when there are static crashes. The problem with MFSK16, as you found, is the mistuning tolerance. For messaging, when there is a fast series of ARQ exchanges, if one station has uncompensated offset between RX and TX (NBEMS must work with untrained and inexperienced operators to be successful for emcomm), and if the offset exceeds 4 Hz, which is not so unusual, eventually it will not be possible to decode MFSK16, and therefore the ARQ requests or confirmations may be missed. This is different from using MFSK16 in a QSO, because in a QSO, it is possible to retune with the mouse after each turnover if necessary, but not very practical in a series of fast ARQ exchanges. We were also testing DSX, which is a variant of DEX, so you would not have been able to decode that. DEX is the name Murray, ZL1BPU, who is working with us to develop the best mode for NBEMS, and is the desiner of MFSK16 and DominoEX, suggested for the new mode, which is NOT compatible with the current DominoEx modes, but uses the same IFK technology so tuning is not critical and static crashes have minimal effect. When we switched to MFSK16, it was to compare very weak reception on one station where there were no static crashes at all. Whereas DEX11 and DEX16 outperformed MFSK16 under the high static conditions, MFSK16 was best when signals were the weakest and there was no static. For NBEMS, we have to compromise between weak signal performance, static crash performance, and transfer speed, and we are still trying to determine which mode to use as a default mode, because it is just not practical to present an untrained operator with a huge selection of different modes for different conditions and ask him, under the pressures of trying to get emergency messages out, to figure out which one to use! Of course, generally, the slower we go in speed, the more robust the mode for a given bandwidth, and there is always a point where a faster mode fails, but a slower one succeeds. In very adverse conditions, when messages tend to be short, such as, We are safe in a shelter at the local school, or The Red Cross has just arrived, any mode that will get the message out, no matter how slowly, is the one that must be used. Connection time tends to be much longer than the message transfer time. Two days ago, a line of severe thunderstorms passed us, and spawned a tornado which touched down about 15 air miles from here, and on 80m, I still have a static level of S9 +10 with strong static crashes almost every second - definitely very adverse conditions! Under these conditions, the new DEX modes are working the best, but at the same time, on 2 meters, there are only occassional weak static crashes, so whenever possible, using VHF is still the best band to use for up to 100 miles. Under these conditions, the PSK modes are quite adequate and also give the fastest transfer speeds. Which PSK speed to use is usually only dependent on the necessary S/N to overcome path loss. I am hoping that most EOC's will install point-to-point VHF circuits for their use rather than relying on 80m and 40m NVIS HF, which is prone to static interference and propagation changes, depending upon the time of day. The advantage to using a relatively narrowband mode on HF is that there is more room for more stations to take traffic simultaneously, which greatly shortens connection time, so the overall time from attempted connection to completion can be much less than having to wait in line to access a few wideband stations. Pactor-II is probably the most efficient ARQ mode developed so far, but it is easy to tell how often connections are not made by observing the number of times client stations come on and never connect, probably because of the small handful of reachable, or available, forwarding stations. I think overall, when we have done all we can to improve our new mode, that in a real emergency, when many stations need to pass traffic at the same time, the throughput of NBEMS will exceed that of other HF systems on the ham bands. We hope to release our latest new mode for beta testing in about two weeks and then everyone will have a chance to try it under all sorts of conditions. 73, Skip NBEMS Development Team
Re: [digitalradio] Signals on 3584 + audio
The problem with knowing where to tune any signal can be solved completely by use of RS ID (as in MultiPSK, PocketDigi etc). It amazes me we have had this technology for over a year now and very few people seem to realize the potential of this. Even with s/n ratios down around -15dB MultiPSK will successfully lock on to the center frequency of any mode and also switch to the correct mode/parameters. In the real world there is always going to be some mis-tuning and although the IFK modes have excellent tolerance in respect to this if someone is 500Hz away they aren't going to decode your transmission, especially if they can't see it on the waterfall. Sending an RS ID before will get them on frequency instantly. 73, Sholto KE7HPV.
[digitalradio] MT63 SKED
I need help finding an MT63 QSO. Can anyone direct me to a time and frequency? (I don't belong to MARS but can receive all frequencies.) Thanks and 73, Fred AK5U
Re: [digitalradio] Signals on 3584 + audio
At 08:49 AM 5/14/2008, kh6ty wrote: The problem with MFSK16, as you found, is the mistuning tolerance. For messaging, when there is a fast series of ARQ exchanges, if one station has uncompensated offset between RX and TX (NBEMS must work with untrained and inexperienced operators to be successful for emcomm), and if the offset exceeds 4 Hz, which is not so unusual, eventually it will not be possible to decode MFSK16, and therefore the ARQ requests or confirmations may be missed. Skip, One thing I have found is that when the sound card can be configured for a 12000 Hz sampling rate, the offsets are not present in most sound cards. It seems that when 11025 is used that the offsets are noticeable in many sound cards. I am not sure how an 8000 Hz sampling rate performs, but just thought I would mention this observation. 73, Mark N5RFX
Re: [digitalradio] Signals on 3584 + audio
Hi Mark, I think G3PLX recently mentioned the same thing, with regard to USB sound cards, as he found they have the biggest offset problems. However, in dealing with the masses, if we can find a way to nullify the offset's effect long enough to complete the ARQ transfer, it will work with anyone, and I think using DEX is the answer, but MFSK16 still appears to be the best mode when there is no static problem, and there is QSB taking the signal below the noise threshold. DominoEX can be mistuned up to 200 Hz and has a 200 Hz drift tolerance, without AFC, so that should take care of most situations. I know that DominoEx16 can be mistuned +/- 100 Hz and still keep printing, because I have tested that multiple times on our 2 meter net. BTW, that brings up another issue - drift tolderance. NBEMS has to deal with transceiver at 2 meters with no TCXO, and transceivers with a TCXO. The drift of the FT-897, for example, is about 50 Hz from start of transmit to about 5 seconds after, and with PSK63, I always lose the initial text from the station without a TCXO, but with DominoEx16, I never lose one character - same as the station with a TCXO, so we think we will replace PSK63 with DominoEX16 for our 2 meter net, after two more weeks of tests to see how it performs with multipath reflections. I'll include mention of the sample rate to use in the Help file. Thanks for the tip! 73, Skip KH6TY - Original Message - From: Mark Miller To: digitalradio@yahoogroups.com Sent: Wednesday, May 14, 2008 1:23 PM Subject: Re: [digitalradio] Signals on 3584 + audio At 08:49 AM 5/14/2008, kh6ty wrote: The problem with MFSK16, as you found, is the mistuning tolerance. For messaging, when there is a fast series of ARQ exchanges, if one station has uncompensated offset between RX and TX (NBEMS must work with untrained and inexperienced operators to be successful for emcomm), and if the offset exceeds 4 Hz, which is not so unusual, eventually it will not be possible to decode MFSK16, and therefore the ARQ requests or confirmations may be missed. Skip, One thing I have found is that when the sound card can be configured for a 12000 Hz sampling rate, the offsets are not present in most sound cards. It seems that when 11025 is used that the offsets are noticeable in many sound cards. I am not sure how an 8000 Hz sampling rate performs, but just thought I would mention this observation. 73, Mark N5RFX -- No virus found in this incoming message. Checked by AVG. Version: 7.5.524 / Virus Database: 269.23.16/1432 - Release Date: 5/14/2008 7:49 AM
[digitalradio] Re: Interface of Choice
I use a usb sound card , 'RDX-150' Ive no idea if its good or bad , but it seems to work just fine on all modes, othere than that in the 'old' p11 1.1 ghz pc , im using a isa awe64 soundblaster, before that , the awe32 full lenght card G .. --- In digitalradio@yahoogroups.com, Clif [EMAIL PROTECTED] wrote: I am contemplating getting into the digital end of ham radio. I have been playing around with listening a little when the band allows. I have been using Ham Radio Deluxe on a Pentium with Win XP and a Kenwood TS870. What is the interface of choice for this combination? Some have PTT control, some use Vox, built-in sound cards??? Too many choices! Clif
[digitalradio] MFSK 'type' very narrow -100 hz bw- mode just seen , what is it ?? 14.072 Mhz
I may allready have it , but what is the mfsk type of mode , looks to be only 100 Hz wide , just noticed it on the digipan waterfall while running psk31 , would of been round 14.072 Khz 1815 hrs gmt Tnx - G ..
[digitalradio] Re: Interface of Choice
--- In digitalradio@yahoogroups.com, Graham [EMAIL PROTECTED] wrote: I use a usb sound card , 'RDX-150' Ive no idea if its good or bad , but it seems to work just fine on all modes, othere than that in the 'old' p11 1.1 ghz pc , im using a isa awe64 soundblaster, before that , the awe32 full lenght card tx/rx I have a 2x com port pci card in the new pc , one feeds the pk232 and the other has a transistor switch which is paralled with the pk232 ptt line o/p G .. --- In digitalradio@yahoogroups.com, Clif clif@ wrote: I am contemplating getting into the digital end of ham radio. I have been playing around with listening a little when the band allows. I have been using Ham Radio Deluxe on a Pentium with Win XP and a Kenwood TS870. What is the interface of choice for this combination? Some have PTT control, some use Vox, built-in sound cards??? Too many choices! Clif
Re: [digitalradio] Interface of Choice
I use rigexpert and it works well. The interface to the computer is USB. Clif wrote: I am contemplating getting into the digital end of ham radio. I have been playing around with listening a little when the band allows. I have been using Ham Radio Deluxe on a Pentium with Win XP and a Kenwood TS870. What is the interface of choice for this combination? Some have PTT control, some use Vox, built-in sound cards??? Too many choices! Clif
Re: [digitalradio] Signal on 3850
John my call is in the yahoo address. So is my real name. As you have a VK call I can understand you not reconising the call of KU4PT being a valid ham call and where it may be. Also as for many years in the USA even having a call with a 4 in it does not mean that I am even in the Southern part of the USA. I hate the FCC did that to us. 73 de KU4PT --- On Wed, 5/14/08, John Simon [EMAIL PROTECTED] wrote: From: John Simon [EMAIL PROTECTED] Subject: Re: [digitalradio] Signal on 3850 To: digitalradio@yahoogroups.com Date: Wednesday, May 14, 2008, 6:39 AM The msg has no signature, no Call, no identification whatsoever. That is why I asked the question. John de VK2XGJ Stop worrying about Life You'll never get out of it alive - Original Message - From: Ralph Mowery [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Wednesday, May 14, 2008 8:17 PM Subject: Re: [digitalradio] Signal on 3850 I am located in the middle of North Carolina, USA --- On Tue, 5/13/08, John Simon [EMAIL PROTECTED] wrote: From: John Simon [EMAIL PROTECTED] Subject: Re: [digitalradio] Signal on 3850 To: digitalradio@yahoogroups.com Date: Tuesday, May 13, 2008, 10:59 PM Ummm, where are you? I can't hear anything here in VK. John de VK2XGJ Stop worrying about Life You'll never get out of it alive
[digitalradio] Digimode Identifiers paper
Hello to all, In the TAPR Spring 2008 PSR Journal ftp://ftp.tapr.org/psr/psr105.pdf it can be found a paper which title is Digimode identifiers. Unfortunatly, it corresponds to the first version that I sent to Stan and not to the modified version that I sent to him several days after (after having written the French version and seen some bugs in the first English version and some missing precisions). This finalized modified English version (RS_ID_English.DOC file) is available from my site. It is included in a ZIP file. To download the ZIP file, paste this adress in your Internet Explorer or equivalent: http://f6cte.free.fr/PAPERS.ZIP Download the ZIP file and extract RS_ID_English.DOC. The content of this paper is the following: * Introduction, * Reed-Solomon identifier (RS-ID) of mode and frequency, - Main use - Principle * The video identifier of mode (Video ID). - Main use - Principle 73 Patrick
[digitalradio] Free Triband Beam, Tower, Rotator
-- Forwarded message -- From: John Hansen [EMAIL PROTECTED] Date: Wed, May 14, 2008 at 9:41 AM I am planning to put up a new HF beam, but need to get rid of the old system first. It consists of a Cushcraft A3S (stainless) 20-15-10 meter beam, a Hygain CD-45II rotator and a 32 foot Rohn HDBX freestanding tower (with the mast, it puts the antenna at about 40 feet). It is available free to anyone who will come and take it down. Here are the details... The antenna: The antenna is in excellent condition, not missing any parts and works quite well. It comes with a balun. The feedline is shot and would need to be replaced. The tower: This is Rohn's heavy duty model (18 sq ft of wind load). It consists of 4 - 8 foot sections. You could add another section or two to it (though at reduced wind load). It is free standing (no guy wires) and hinges at the base so it can tilt over. Currently it is in something called an earth base. This is a steel cylinder about two feet in diameter and 4 feet deep. It allows the tower to be supported without concrete. The tower has been held up by this base through significant wind storms for about 15 years. If you use this base, there is no need to buy and install any concrete for the tower. However, to use this base you would have to dig the dirt out of the center of the base to remove it. I'm pretty sure I also have the original (unused) tower legs that could be used instead if you want to install the tower in concrete. The tower is rusty and should be repainted, but it is structurally sound. The rotor: Both the rotor and the control box need repair. There are shops that will remanufacture/repair these things (see, for example, www.rotorservice.com) for a very reasonable price. This package is available for free if you get together a group of people and take it down. The easiest way to do this (I've done it before) is to get about a 60 foot piece of heavy rope and attach it at about the 20 foot level of the tower. Then one group of people can stand in a bedroom of my house easing the rope down and another group can stand behind the tower and lower it. A pile of concrete blocks can hold the top of the tower off the ground so that the antenna doesn't actually hit the ground. Then the antenna can be removed and the tower disassembled. However, it has been a quite a number of years since it was last lowered and I expect the tower bolts will be quite rusty. Antenna is located FN02hk
[digitalradio] Overheating PC?
Please excuse the not-directly ham related issue. A PC I have used for 2 years without issues is suddenly closing down due to overheating. At quick glance the CPU fan appears to be working but will run temp tests. Any other suggestions if not CPU fan? -- Andy K3UK www.obriensweb.com (QSL via N2RJ)
Re: [digitalradio] Overheating PC?
Couple of problems I've come across, Andy: 1. The heat sink on the top of the processor has loosened up, and is no longer making solid contact with the processor itself. It could look solid, but if it separates from the CPU even a little, it can cause overheating. 2. The fan is working, but due to age, dust, it has slowed down to the point it is ineffective. 3. Dust build-up on either in inflow or outflow vents for the fan(s). If either in or out goes through the power supply, it's sometimes difficult to see the buildup without opening the supply. On my old Gateway, there was a fan on the cpu itself, but it blew hot air directly into the power supply! Talk about overheating! What wattage is your power supply rated at? Most PCs come with 200 to 300 watt supplies, which may be adequate for the base system, but if you add peripherals, such as USB sound cards, CD Burners, video cards, additional memory, and so on, it taxes the power supply so much that it can overheat. Hope this gives some clues! 73 Dave KB3MOW Andrew O'Brien wrote: Please excuse the not-directly ham related issue. A PC I have used for 2 years without issues is suddenly closing down due to overheating. At quick glance the CPU fan appears to be working but will run temp tests. Any other suggestions if not CPU fan? -- Andy K3UK www.obriensweb.com (QSL via N2RJ) No virus found in this incoming message. Checked by AVG. Version: 8.0.100 / Virus Database: 269.23.16/1433 - Release Date: 5/14/2008 4:44 PM
[digitalradio] Re: Overheating PC?
Maybe the fan in the power supply...they are most fragile Rick W3BI --- In digitalradio@yahoogroups.com, Andrew O'Brien [EMAIL PROTECTED] wrote: Please excuse the not-directly ham related issue. A PC I have used for 2 years without issues is suddenly closing down due to overheating. At quick glance the CPU fan appears to be working but will run temp tests. Any other suggestions if not CPU fan? -- Andy K3UK www.obriensweb.com (QSL via N2RJ)
Re: [digitalradio] Re: Overheating PC?
Just load Speedfan on that PC and interestingly it lists no fansm so no temp display. The HD temp is diplayed, not a fan. I will have to research and see if CPU temp monitoring devices are on this cheap Emachine. 300 Watt power supply On Wed, May 14, 2008 at 7:39 PM, w3bi2 [EMAIL PROTECTED] wrote: Maybe the fan in the power supply...they are most fragile Rick W3BI --- In digitalradio@yahoogroups.com, Andrew O'Brien [EMAIL PROTECTED] wrote: Please excuse the not-directly ham related issue. A PC I have used for 2 years without issues is suddenly closing down due to overheating. At quick glance the CPU fan appears to be working but will run temp tests. Any other suggestions if not CPU fan? -- Andy K3UK www.obriensweb.com (QSL via N2RJ) -- Andy K3UK www.obriensweb.com (QSL via N2RJ)
Re: [digitalradio] Signals on 3584 + audio
That is interesting that they are going to name a new mode DEX that is similar to, but not the same as DominoEX. I liked using DEX as the acronym for DominoEX. But the creator gets to pick the names. I am very pleased that Murray is helping to develop a mode for NBEMS and I am sure many of us will be quite interested when this gets to the point that we can try it out. Same for DSX. We have got to make this simple to use and I hope that there will be more interest on digital modes for public service. Nothing much happening in our area and I do promote it as much as I can. Pactor 2 is the mode to beat since it is has so many good attributes for its bandwidth. It would be great to see some comparisons between P2 and the newer sound card modes. Thanks to all of you for so much work to develop these new modes. 73, Rick, KV9U kh6ty wrote: Hi Rick, FYI, our tests last night indicate that MFSK16 still copies the best at low S/N, but only when there are no static crashes, but DEX16 or DEX11 have much fewer errors when there are static crashes. The problem with MFSK16, as you found, is the mistuning tolerance. For messaging, when there is a fast series of ARQ exchanges, if one station has uncompensated offset between RX and TX (NBEMS must work with untrained and inexperienced operators to be successful for emcomm), and if the offset exceeds 4 Hz, which is not so unusual, eventually it will not be possible to decode MFSK16, and therefore the ARQ requests or confirmations may be missed. This is different from using MFSK16 in a QSO, because in a QSO, it is possible to retune with the mouse after each turnover if necessary, but not very practical in a series of fast ARQ exchanges. We were also testing DSX, which is a variant of DEX, so you would not have been able to decode that. DEX is the name Murray, ZL1BPU, who is working with us to develop the best mode for NBEMS, and is the desiner of MFSK16 and DominoEX, suggested for the new mode, which is NOT compatible with the current DominoEx modes, but uses the same IFK technology so tuning is not critical and static crashes have minimal effect. When we switched to MFSK16, it was to compare very weak reception on one station where there were no static crashes at all. Whereas DEX11 and DEX16 outperformed MFSK16 under the high static conditions, MFSK16 was best when signals were the weakest and there was no static. For NBEMS, we have to compromise between weak signal performance, static crash performance, and transfer speed, and we are still trying to determine which mode to use as a default mode, because it is just not practical to present an untrained operator with a huge selection of different modes for different conditions and ask him, under the pressures of trying to get emergency messages out, to figure out which one to use! Of course, generally, the slower we go in speed, the more robust the mode for a given bandwidth, and there is always a point where a faster mode fails, but a slower one succeeds. In very adverse conditions, when messages tend to be short, such as, We are safe in a shelter at the local school, or The Red Cross has just arrived, any mode that will get the message out, no matter how slowly, is the one that must be used. Connection time tends to be much longer than the message transfer time. Two days ago, a line of severe thunderstorms passed us, and spawned a tornado which touched down about 15 air miles from here, and on 80m, I still have a static level of S9 +10 with strong static crashes almost every second - definitely very adverse conditions! Under these conditions, the new DEX modes are working the best, but at the same time, on 2 meters, there are only occassional weak static crashes, so whenever possible, using VHF is still the best band to use for up to 100 miles. Under these conditions, the PSK modes are quite adequate and also give the fastest transfer speeds. Which PSK speed to use is usually only dependent on the necessary S/N to overcome path loss. I am hoping that most EOC's will install point-to-point VHF circuits for their use rather than relying on 80m and 40m NVIS HF, which is prone to static interference and propagation changes, depending upon the time of day. The advantage to using a relatively narrowband mode on HF is that there is more room for more stations to take traffic simultaneously, which greatly shortens connection time, so the overall time from attempted connection to completion can be much less than having to wait in line to access a few wideband stations. Pactor-II is probably the most efficient ARQ mode developed so far, but it is easy to tell how often connections are not made by observing the number of times client stations come on and never connect, probably because of the small handful of reachable, or available, forwarding stations. I think overall, when
Re: [digitalradio] Signals on 3584 + audio
You know what? I have not used RS ID much as of late and it never even entered my mind to use this last night. But then again, both stations need to use Multipsk for that to work. Are any other programs going to be adding the technology? 73, Rick, KV9U Sholto Fisher wrote: The problem with knowing where to tune any signal can be solved completely by use of RS ID (as in MultiPSK, PocketDigi etc). It amazes me we have had this technology for over a year now and very few people seem to realize the potential of this. Even with s/n ratios down around -15dB MultiPSK will successfully lock on to the center frequency of any mode and also switch to the correct mode/parameters. In the real world there is always going to be some mis-tuning and although the IFK modes have excellent tolerance in respect to this if someone is 500Hz away they aren't going to decode your transmission, especially if they can't see it on the waterfall. Sending an RS ID before will get them on frequency instantly. 73, Sholto KE7HPV.
[digitalradio] RS ID / Video ID
With Multipsk, FLDIGI and DM780 all using Video ID, maybe that is the best for now, Andy On Wed, May 14, 2008 at 9:58 PM, Rick [EMAIL PROTECTED] wrote: You know what? I have not used RS ID much as of late and it never even entered my mind to use this last night. But then again, both stations need to use Multipsk for that to work. Are any other programs going to be adding the technology? 73, Rick, KV9U Sholto Fisher wrote: The problem with knowing where to tune any signal can be solved completely by use of RS ID (as in MultiPSK, PocketDigi etc). It amazes me we have had this technology for over a year now and very few people seem to realize the potential of this. Even with s/n ratios down around -15dB MultiPSK will successfully lock on to the center frequency of any mode and also switch to the correct mode/parameters. In the real world there is always going to be some mis-tuning and although the IFK modes have excellent tolerance in respect to this if someone is 500Hz away they aren't going to decode your transmission, especially if they can't see it on the waterfall. Sending an RS ID before will get them on frequency instantly. 73, Sholto KE7HPV. -- Andy K3UK www.obriensweb.com (QSL via N2RJ)
Re: [digitalradio] RS ID / Video ID
Andy, Video ID is nice but when sent horizontal it has a very low average power so won't work well in poor conditions. The RS ID is sequential MFSK and will have 100% power. Also the Video ID doesn't automatically tune in your software. In MultiPSK it is possible to use both types of ID before a transmission and this is useful if testing out a relatively unknown mode and you want others who don't run MultiPSK to know what you are transmitting in and those that do to automatically switch modes. The only thing I would warn against is using the Video ID in an ARQ mode as it adds a significant delay to the switching. ALE400 FAE has the ability to transmit the RS ID only on initial calls and connects and then it is turned off for the duration of the QSO. An upshot of this is that if you know there is a MultiPSK enabled machine on frequency you can SELCAL it and make the link without the other operator doing anything. Even if you are off tune the other machine will home in on your signal and if it is the right call it will respond to you. I have used this to successfully send John VE5MU an email with a binary attachment without any intervention required by him. Of course the ARQ nature of ALE400 FAE means that the email + attachment get sent without error and you are notified that the sending was successful. 73, Sholto. Andrew O'Brien wrote: With Multipsk, FLDIGI and DM780 all using Video ID, maybe that is the best for now, Andy On Wed, May 14, 2008 at 9:58 PM, Rick [EMAIL PROTECTED] wrote: You know what? I have not used RS ID much as of late and it never even entered my mind to use this last night. But then again, both stations need to use Multipsk for that to work. Are any other programs going to be adding the technology? 73, Rick, KV9U Sholto Fisher wrote: The problem with knowing where to tune any signal can be solved completely by use of RS ID (as in MultiPSK, PocketDigi etc). It amazes me we have had this technology for over a year now and very few people seem to realize the potential of this. Even with s/n ratios down around -15dB MultiPSK will successfully lock on to the center frequency of any mode and also switch to the correct mode/parameters. In the real world there is always going to be some mis-tuning and although the IFK modes have excellent tolerance in respect to this if someone is 500Hz away they aren't going to decode your transmission, especially if they can't see it on the waterfall. Sending an RS ID before will get them on frequency instantly. 73, Sholto KE7HPV.
