SCS model numbers and pactor modes are confusing. Current modems in production are the PTC-IIIusb and the P4dragon, and are recommended. Any previous PTC-II, IIe, IIex, IIpro, or IIusb modem can be licensed to use the Pactor-III protocol for a fee (paid to an SCS dealer or to SCS, not to SailMail) but can’t be used for P4. Pactor-III transfers data 3-4x faster than Pactor-II with good signals, and is slightly faster than Pactor-II even with weak signals. P4 is somewhat faster still, particularly with strong signals. We strongly encourage all members to use at least Pactor-III. SailMail’s stations are all capable of all modes including Pactor-4. We expect that PTC-II-family modems (licensed to use Pactor-III) will continue to be used by most SailMail members because of the significantly lower cost. But for those with greater communications needs, Pactor-4 offers a way to increase capacity. Pactor-III mode was developed after the PTC-II and PTC-IIe were introduced, and was an “option”– part of the newer firmware-updates but had to be “unlocked” with a purchased license-code. For later modems this Pactor-III license-code was keyed to the modem’s electronic serial# (ESN) and was transferable with the modem. For earlier modems, all PTC-II’s and early production PTC-IIe units, without an ESN, the original policy was for SCS to issue a license code that was keyed to the user’s callsign. This license-codes are not transferable to a new owner and are no longer available. If you have a PTC-II or early PTC-IIe that does not have an ESN (i.e. no barcode sticker on the bottom), it may be possible to have the modem retrofit with a hardware ESN. contact Gary at Farallon Electronics to find out. If it is possible, the ESN retrofit and P3 license will cost around $350.
Leave the modem selection in AirMail set to your modem model number. If your modem has indeed been upgraded to Pactor-III mode then Airmail will detect that, and use it. Continue reading