Most of the radio equipment that hams use today are commercial products. Of course some do home brew them as well, and some, such as myself make many other devices (active antennas, meters, QRP rigs, interfaces, crystal calibrators, etc.) from various parts, some even recycled:). But even those home brew items mostly use commercial parts.
The commercial modes are those that are intended to be sold on the commercial market. They are made specifically for that market and are not made for amateur radio use and don't tend to work well for what we are doing, which is mostly slow keyboard to keyboard between human operators. For example, you do not see any narrow modes for sale commercially that are readily available for hams to use, e.g., PSK31, MFSK16, Throb, DominoEX, etc. And then there are variants of the commercial modes that are primarily intended for ham use, such as when Sitor was adapted to Amtor, X.25 was adapted for packet AX.25, and recently when the ALE 8FSK125 mode was adapted as a modified ARQ mode as FAE in the Multipsk program. These programs are not intended to be sold as a commercial product. The interest, and to a certain extent, the ability of those who have been writing programs for amateur radio has been primarily for keyboard modes and not for serious emergency communications or high throughput ARQ modes, nor automatically adaptable modes that can adjust for conditions. I am not sure if it is a good idea to be using the ham bands for personal e-mail access since there really is not enough room to be doing this for more than a very few hams. If the average ham decided to do this, we would have serious problems. Look what happened to even the much wider (but short range) packet networks which eventually could not handle the amount of traffic going through and became nearly unusable for multi-digipeating for conversational purposes. I do support the development of the high speed HF modes for emergency use and for networks that frequently exercise this capability. If you don't use it for some other purposes, it won't be built and it won't be working when you need it. But we need to be careful about developing commercial use. I appreciate your comments about Pactor 3 as this is some good information that lets us know that it can often operate at Level 4 using the DQPSK waveform with 14 tones, thus the 14 x 100 baud x 2 bits per baud = 2800 raw throughput. If it is forced to move to the next lower speed it drops in performance by half since at Level 3 it drops DQPSK and moves to DBPSK, but still using the 14 tones which gives you 14 x 100 baud x 1 bit per baud = 1400 raw bps which is less than 600 bps before compression. Even at the next lower level, at level 2, where it drops to only 6 tones with DBPSK, that gives you 6 x 100 x 1 bit per baud = 600 bps raw. They show the net bps at just under 250 bps. This is still a good speed and with compression should nearly double for many types of text. It should work well below the noise but it would be a wide bandwidth mode. Since the tones have mostly double the spacing of 240 Hz instead of the normal 120 Hz spacing, this should make it more robust. The slowest mode has extremely wide spacing of 720 Hz for only two tones or 2 x 100 x 1 bit per baud = 200 but with about 77 bps raw net throughput plus compression bringing it well over 100 bps and should be as robust as anything we now have for a keyboard mode (except much wider). With the DSP power of today's computers, we can have competitive modes with Pactor using sound cards. After all, the Pactor box is basically a dedicated computer with the equivalent of a sound card to send the tones to the rig. Because it is a real time kind of system, it is much easier to provide exact timing for switching speeds but we don't need to do that. 73, Rick, KV9U Demetre Valaris - SV1UY wrote: > As for PACTOR 3 and how it works, I think that Rick KV9U has already given > you an explanation. I must add that the good thing about PACTOR is that it > can adapt very fast to conditions and decrease or increase it's > speed/packetsize accordingly. I think that if a programmer could improvise a > mode that does exactly that, then he will have hit bull's eye on digital > modes. Now I am not sure why you call PACTOR a commercial mode. All the > radios we use are also commercial? since we have to pay for them?. Also our > laptops are commercial as well? Noone complains using them even if they have > Windows (a proprietary OS). I do not think that condeming anything is going > to go away. Can we make something similar or even better? This is the > challenge. Let's try to make a fast digital mode similar even to PACTOR 2 > which does 1200 bps on a 0.5 KHZ channel by taking lessons from > this "commercial" mode. > > Indeed when conditions are good, PACTOR and especially PACTOR 3, really > flies (even when I use it with my FT-817, a radio which I paid for, just > like my SCS-PTC, or KAM, or my desktop and laptop computer and a 2 meter > whip as an HF aerial). I usually see a raw speed of 2800 bps on an average > HF channel and throughput of around 3000 estimated roughly, but I will make > some notes and let you know more details if you wish. I have seen 3600 raw > speed a few times but since HF is rarely good and since I do not use PACTOR > 3 every minute of the day, it happens rarely. I have 2 SCS-PTC controllers > here supporting P 1-3 and also KAM-Plus and a homemade modem with G4BMK > Multi (a DOS program) that support PACTOR 1. Well I must tell you there is a > hell of a difference is speed compared to anything else. All PACTOR modes > (including PACTOR 1) are far more superior than anything else I have ever > used on HF. I also use many of the soundcard modes with a proper interface > on HF and they seem like toys compared even to PACTOR 1. Soundcard modes are > OK for starting on DIGITAL MODES but leave a lot to be desired for speed if > you want speed on HF that is. If you are only interested in DIGITAL OSOs > (which is OK for many people) then they are OK, but I guess they should get > faster, a lot faster. > > Enough said. > > I hope to see you both tonight on ARQ-FAE. > > --- > 73 de Demetre Valaris - SV1UY > e-mail: [EMAIL PROTECTED] > AX25 PBBS: [EMAIL PROTECTED] > http://sv1uy.ampr.org/~sv1uy > http://www.athnet.ampr.org/~sv1uy > > > > Announce your digital presence via our Interactive Sked Page at > http://www.obriensweb.com/drsked/drsked.php > > Yahoo! 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