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 RFSMxxxx 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. > RFSMxxxx 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
