Re: [digitalradio] Re: RFSM file transfer
Hi Matt, I think that Steve is making more of the DLP legal issues than is warranted. Again, I would be that they would respond to a request for interpretation by either saying no problem, or just ignoring the request. Maybe true of NTIA? Question: what kind of speeds are you seeing under different conditions? When some of us tested it a while back on the ham bands (mostly Canadian-US in the US image portions of the bands) the throughput was around 600 bps if I remember right. This was with signals that would normally be just at SSB phone communications capable, but not really strong signals with a high SNR of say 20 or 30 dB. Compared to any other linking protocol available with current sound card protocols, I found the RFSM modem to be the best in terms of ease of use. Just about anyone could run the program for the first time and figure out how to send a message to another station running the same software. In fact, the way that RFSM worked was almost identical to the precursor to Winmor (SCAMP) about three years ago even though the RDFT protocol was used back then. It is my view, that this is the way that software must work in the long term, in order to get wide adoption for emergency use. It needs to be simple, and easily used for any kind of set up. 73, Rick, KV9U matt gregory wrote: Steve, This software is being used by a handful of regions in two of the three services. why ? this now gives stations the capability to send messages at very fast speed with out having to purchase very expensive hardware. which makes us all more efficient.* From:* shajducek [EMAIL PROTECTED] As to Matt's use of it on MARS, there too its prohibuted as it needs approval for use since its not using a standard DLP such as FS1052DLP or S5066DLP.
Re: [digitalradio] Re: RFSM file transfer
Steve, This software is being used by a handful of regions in two of the three services. why ? this now gives stations the capability to send messages at very fast speed with out having to purchase very expensive hardware. which makes us all more efficient. From: shajducek [EMAIL PROTECTED] As to Matt's use of it on MARS, there too its prohibuted as it needs approval for use since its not using a standard DLP such as FS1052DLP or S5066DLP.
[digitalradio] Re: RFSM file transfer
Hi Rick, The last time I checked they had still not released the details of the Data Link Protocol (DLP) being used, which could be just about anything by the way, which means FCC rules make it's use illegal. As to Matt's use of it on MARS, there too its prohibuted as it needs approval for use since its not using a standard DLP such as FS1052DLP or S5066DLP. Anyhow, to get full performance from any MIL-STD-188-110 PSK modem the radio IF BW needs to be wide enough for the symbol rate and PSK carrier being used, which in full up standard mode is a full 3Khz, This is especially critical with more channel QSB to achieve the needed error correction rate. /s/ Steve, N2CKH --- In digitalradio@yahoogroups.com, Rick W [EMAIL PROTECTED] wrote: Several of us have tested RFSM2400 on HF and some local hams have tested it with me on VHF. While you do need pretty good signals to work at the higher speeds, it can work quite well as long as signals are high enough above zero dB SNR to permit throughput at the slowest speed. I like the idea of having one basic software package that covers a wide spectrum of conditions and has a very basic and understandable appearance on the computer screen. You can use these high baud rate single tone MIL-STD-188-110 modems here in the U.S. throughout most of the VHF and higher bands and also it is my view that they can be used to transmit images and FAX in the phone/image portions of the bands. I doubt that the FCC will give you any grief if you do that. If you had the commercial product, which has a server, I think you could also act as a gateway station to forward e-mail into the internet. John, VE5MU, would know how that is done. 73, Rick, KV9U
Re: [digitalradio] Re: RFSM file transfer
The program claims to be compatible with MIL-STD 188-110, thus it would be very surprising if the FCC did not allow its use here in the U.S. I suppose if it did not interoperate with any other MIL-STD-188-110 modem, then you could get suspicious about how it functions, but almost no hams would have such a modem available to them for testing, HI. Since RFSM2400 also includes a non-standard mode made specifically for ham audio bandwidth use it does not seem that this is a limiting factor. It is probably a moot point since it is likely not being used by many (any?) of us due to its limitations. It is doubtful that I will be using it anymore since further development on the free version has been discontinued and I it is rare that anyone will pay for digital ham software now that there are so many good programs available that can outperform MIL-STD-118-110 when the signals become weak ... which is so often the case on ham frequencies. The main use of high speed modems has been for casual e-mail use when conditions are good enough to permit such transfers. There is some interest in being able to send larger documents and images, by a few of us, but it is a very small subset of hams and I have not seen much interest from others. 73, Rick, KV9U shajducek wrote: Hi Rick, The last time I checked they had still not released the details of the Data Link Protocol (DLP) being used, which could be just about anything by the way, which means FCC rules make it's use illegal. As to Matt's use of it on MARS, there too its prohibuted as it needs approval for use since its not using a standard DLP such as FS1052DLP or S5066DLP. Anyhow, to get full performance from any MIL-STD-188-110 PSK modem the radio IF BW needs to be wide enough for the symbol rate and PSK carrier being used, which in full up standard mode is a full 3Khz, This is especially critical with more channel QSB to achieve the needed error correction rate. /s/ Steve, N2CKH
[digitalradio] Re: RFSM file transfer
Hi Rick, --- In digitalradio@yahoogroups.com, Rick W [EMAIL PROTECTED] wrote: The program claims to be compatible with MIL-STD 188-110, thus it would be very surprising if the FCC did not allow its use here in the U.S. There is modem ( MIL-STD-188-110 ) and its mode ( PSK serial tone ) that comes into play and the data link protocol layer ( e.g. FED-STD- 1052 DLP or S5066 DLP or other ) to consider, regarding the RFSM it is the details of this layer that is unknown. I suppose if it did not interoperate with any other MIL-STD-188-110 modem, then you could get suspicious about how it functions, but almost no hams would have such a modem available to them for testing, HI. RFSM is only compatible onto itself as its non-standard. Since RFSM2400 also includes a non-standard mode made specifically for ham audio bandwidth use it does not seem that this is a limiting factor. That is at the modem ( MIL-STD-188-110 ) layer where you can select the symbol rate and PSK carrier to reduce the IF BW reguirment, a number of today's hardware MIL-STD-188-110 modems can also do so, I did so with MARS-ALE in PC Sound Device based software modems and others such as the RFSM boys have followed that lead as the standard symbol rate of 2400bps and PSK carrier of 1800hz requires a full 3Khz IF BW which is a problem when not using Military grade HF transceivers for the most part. It is probably a moot point since it is likely not being used by many (any?) of us due to its limitations. It is doubtful that I will be using it anymore since further development on the free version has been discontinued and I it is rare that anyone will pay for digital ham software now that there are so many good programs available that can outperform MIL-STD-118-110 when the signals become weak ... which is so often the case on ham frequencies. Your view is short sighted in this regard in my opinion Rick. The use of PCSDM based MIL-STD-188-110 modems and a given DLP is just the ticket for properly configured Amateur stations looking to make use of high speed HF communications as a dediated PC to such communications is far less expensive and more versatile compared to any hardware based modem/DLP. Such communications as I view the world are NVIS based ECOM rather than Skywave, where any Amateur can setup a good NVIS antenna and operate at 100w ( which due to multi-path you don't want to exceed on NVIS paths ) power levels. However, here in the U.S. it is rather moot as FCC rules prohibit us from taking full advantage of MIL-STD-188-110 modems. I no longer get this forum in my e-mail, I have not since last winter, I as looking at list of forums I subscribe to today an opened this one to see what the current topics were and looked back at the last two weeks worth of posts, it seems to have calmed down here a lot, perhaps I will turn it back on for daily e-mails. /s/ Steve, N2CKH
Re: [digitalradio] Re: RFSM file transfer
Hi Rick and Steve, I confirmed with the author that the DLP layer was not standard. Further, they are not too likely to release it because they believe it is better than the standard. Based on this, the FCC may not allow it. My testing confirms that it works very well. Under 'fair' conditions, this is the fastest software for transferring messages. (I do not include Pactor 2 or 3 in this comparison because I do not have those modes and they are not available in software.) Perhaps the WINMOR modem will work well too. Howard K5HB From: shajducek [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Friday, October 31, 2008 11:54:43 AM Subject: [digitalradio] Re: RFSM file transfer Hi Rick, --- In digitalradio@ yahoogroups. com, Rick W [EMAIL PROTECTED] wrote: The program claims to be compatible with MIL-STD 188-110, thus it would be very surprising if the FCC did not allow its use here in the U.S. There is modem ( MIL-STD-188- 110 ) and its mode ( PSK serial tone ) that comes into play and the data link protocol layer ( e.g. FED-STD- 1052 DLP or S5066 DLP or other ) to consider, regarding the RFSM it is the details of this layer that is unknown. I suppose if it did not interoperate with any other MIL-STD-188- 110 modem, then you could get suspicious about how it functions, but almost no hams would have such a modem available to them for testing, HI. RFSM is only compatible onto itself as its non-standard. Since RFSM2400 also includes a non-standard mode made specifically for ham audio bandwidth use it does not seem that this is a limiting factor. That is at the modem ( MIL-STD-188- 110 ) layer where you can select the symbol rate and PSK carrier to reduce the IF BW reguirment, a number of today's hardware MIL-STD-188- 110 modems can also do so, I did so with MARS-ALE in PC Sound Device based software modems and others such as the RFSM boys have followed that lead as the standard symbol rate of 2400bps and PSK carrier of 1800hz requires a full 3Khz IF BW which is a problem when not using Military grade HF transceivers for the most part. It is probably a moot point since it is likely not being used by many (any?) of us due to its limitations. It is doubtful that I will be using it anymore since further development on the free version has been discontinued and I it is rare that anyone will pay for digital ham software now that there are so many good programs available that can outperform MIL-STD-118- 110 when the signals become weak ... which is so often the case on ham frequencies. Your view is short sighted in this regard in my opinion Rick. The use of PCSDM based MIL-STD-188- 110 modems and a given DLP is just the ticket for properly configured Amateur stations looking to make use of high speed HF communications as a dediated PC to such communications is far less expensive and more versatile compared to any hardware based modem/DLP. Such communications as I view the world are NVIS based ECOM rather than Skywave, where any Amateur can setup a good NVIS antenna and operate at 100w ( which due to multi-path you don't want to exceed on NVIS paths ) power levels. However, here in the U.S. it is rather moot as FCC rules prohibit us from taking full advantage of MIL-STD-188- 110 modems. I no longer get this forum in my e-mail, I have not since last winter, I as looking at list of forums I subscribe to today an opened this one to see what the current topics were and looked back at the last two weeks worth of posts, it seems to have calmed down here a lot, perhaps I will turn it back on for daily e-mails. /s/ Steve, N2CKH
Re: [digitalradio] Re: RFSM file transfer
Since the modem is readily available for anyone, including the FCC to use, I don't see any of this as a problem. I might agree that technically speaking, it could be a violation of the rules as you point out, but I suspect that if asked, the FCC would either say no problem, or more likely would just not respond, (which seems to be one of their solutions for dealing with sticky issues in the past year). It appears from your comments that you believe that I do not support sound card modems. Clearly, I most emphatically do, but not necessarily this specific product. If someone else came along and developed a MIL-STD-188-110A, or even an MIL-STD-188-141B, Appendix C modem, I would find it very interesting provided there was no charge. As you know, I have spent a great deal of time researching MIL-STD/FED-STD/STANAG systems and have published some (hopefully) helpful outline on the hfdec yahoogroup site that looks at the three generations and maybe make some sense of what is a fairly complicated series of improvements over the past 25 + years. Direct comparisons of multi tone and single tone modems have been fairly close for a given bandwidth. I have seen at least one study that did suggest (based on projections, not total empirical data) that the multi tone may work better overall. This was for a difficult and necessarily low angle (non-NVIS) path to the south pole. Power used was in many cases, well above amateur levels. Even then, only certain hours of the day were available for any traffic to be passed depending upon ionospheric conditions. I am very open to any of these technologies and no particular bias. In fact, I have been one of the few hams who have actually tested some of these technologies. Frankly, most hams show very little interest:( I do have a healthy skepticism toward high speed single tone modems becoming popular for amateur use. Unlike military use, we do not have the ability to install the kinds of antennas that they do nor can we keep increasing power levels like they do to overcome difficult conditions. Even NVIS has its limitation. Most of us have to slow down the throughput with our more modest equipment, antennas, and power levels. But we can get the data through if we use ARQ modes, even if more slowly. I have not seen much hardware adoption of modems since the inception of PSK31. The main exception may be Pactor and Pactor2 and Pactor 3 use, especially for HF Winlink 2000. But even there we are seeing a renewed movement toward sound card technology after a hiatus of three years. [ Important clarification: I am not inherently opposed to paying for software, and I have spent hundreds of dollars in the past.. My experience has shown that when digital mode software (often true of any software) becomes freely available, adoption of similar software that has monetary cost is quite reduced and you may not have enough hams to meaningfully participate. And anything new, hardware or software, must have some compelling reasons for adoption. RFSM tests that I tried were competitive with existing software under some conditions, but not really that compelling either. ] Speaking for myself (others may view this differently) I would prefer open source, but ideally free as in beer, if not free as in speech. We have that now with at least one multi-mode digital cross platform software suite with fldigi and flarq. It is definitely a changing landscape from just a year or two ago. 73, Rick, KV9U shajducek wrote: There is modem ( MIL-STD-188-110 ) and its mode ( PSK serial tone ) that comes into play and the data link protocol layer ( e.g. FED-STD- 1052 DLP or S5066 DLP or other ) to consider, regarding the RFSM it is the details of this layer that is unknown. That is at the modem ( MIL-STD-188-110 ) layer where you can select the symbol rate and PSK carrier to reduce the IF BW reguirment, a number of today's hardware MIL-STD-188-110 modems can also do so, I did so with MARS-ALE in PC Sound Device based software modems and others such as the RFSM boys have followed that lead as the standard symbol rate of 2400bps and PSK carrier of 1800hz requires a full 3Khz IF BW which is a problem when not using Military grade HF transceivers for the most part. Your view is short sighted in this regard in my opinion Rick. The use of PCSDM based MIL-STD-188-110 modems and a given DLP is just the ticket for properly configured Amateur stations looking to make use of high speed HF communications as a dediated PC to such communications is far less expensive and more versatile compared to any hardware based modem/DLP. Such communications as I view the world are NVIS based ECOM rather than Skywave, where any Amateur can setup a good NVIS antenna and operate at 100w ( which due to multi-path you don't want to exceed on NVIS paths ) power levels. However, here in the U.S. it is rather moot as FCC rules
Re: [digitalradio] Re: RFSM file transfer
I too would like to see this and I think that I have asked this same question in the past but the only hams who can do this are those who have the SCS modems, so it is a very small number. The main limitation of the RFSM modems seems to be when the signals are weaker than around +5 or 10 above zero dB SNR. Then they can not provide throughput since they do not implement the slower and more robust speeds of the MIL-STD-188-110 standard. I am assuming that they have not added the robust STANAG modes but have not heard that they have done further development for that purpose. Pactor 2 and 3 are able to work very much deeper into the noise and may even be able to compete well with the most robust soundcard modes under difficult conditions. The reason I say may, is because we don't really know, since there have not be tests like Tony has been doing with the sound card modes that compare throughput with varying amounts of Doppler and multipath. Since Pactor 2 and 3 use PSK type modes, they may not be all that robust against certain kinds of conditions with high levels of ISI. My suspicion is that the operator would never know, especially if they are trying to connect with an automated station. There are likely times that they would not connect even though they might hear each other. But when signals are quite strong, even with some ISI/Doppler, etc., the RFSM modems should do well based upon the experiences of other operators mentioned in the past day or so. My tests have not been so favorable, but the signals were more typical of HF where you are just at phone quality communications, but not really all that strong either. 73, Rick, KV9U kf4wbs wrote: CAN YOU COMPARE RFSM 8000 TO PACTOR III UNDER SIMILAR CONDITIONS ?
[digitalradio] Re: RFSM file transfer
CAN YOU COMPARE RFSM 8000 TO PACTOR III UNDER SIMILAR CONDITIONS ? --- In digitalradio@yahoogroups.com, Les Keppie [EMAIL PROTECTED] wrote: Hi Tommi In testing here in VK - VK2JN and VK2DSG have passed files in excess of 4 Mb on 80m band - best time seems to be late afternoon when atmospheric noise is a lesser problem Both stations here using licenced versions of RFSM8000 VER .534 To achieve these speeds around the 3000 bps you do require quite good S/NR figures - but who is going to try and pass a 4mb file if S/NR is -5 - just forget about it until you have good conditions Sound card calibration is another thing that requires some attention using this program to get the best transfer speeds Here in VK we both used CheckSR.exe from MixW - and Calibrate.exe from RFSM8000 - later withdrawn by author But we used to calibrate with both programs and then made an average reading of both results and used this in the tx/rx soundcard setup In my opinion - a good program for use on HF - given fair to good conditions and maybe a lot better on VHF Regards Les VK2DSG From: Tommi Holopainen Sent: Monday, October 13, 2008 6:04 AM To: digitalradio@yahoogroups.com Subject: [digitalradio] RFSM file transfer Hello Just wondering has anybody else tryed transfer quite big files on HF with RFSM or some other mode?. We just tranfered OH7TE --- OH7JJT Big 1.3 MB file 80m band. File was simply zipped program file. Propagation on 80m band was not very good, some qrm, aurora and fading as usually here dark time. We had abt 400 km QRB. Transfer time was about 1 hour Stations setup: OH7JJT: Yaesu FT 990 40 w Dipole abt 8 m up Software RFSM 8000 version 0.534 OH7TE JUMA TRX2A Digi Mode Edition + Lauta Mosfet PA abt 60 w Dipole up 12m Software RFSM 8000 version 0.534 -Tommi OH7JJT-
