TO: FEDERAL COMMUNICATIONS COMMISSION FROM; AMCOM, INC. WFN SUBJ: EVALUATION OF TELETYPE ON THE INLAND WATERWAYS Dear Sirs, Enclosed you will find a complete evaluation of the teletype system that was used by WFN and the M/V Joe Pickering KVBH We found that the increase in power was probably the most significant factor in the reliability of the system, over what we had previously used. We found that the system not only met, but surpassed all expectations we had anticipated. The only limitation we found to exist, was that of propagation, and this could have been overcome with the assignment of a 2 MHz frequency. The Joe Pickering operated in the Cairo, Illinois area while the tests wore conducted. Radio Station WL0 in Mobile, Alabama, also copied our signal when there were operators available to do so. Both stations reported no difficulty in copying the traffic that was sent. The Joe Pickering copied all transmissions 100 percent, when sent between the hours of 0600 and 2000. After 2000 and before 0600 the propagation was such that the signal could not be copied. We are of the opinion that the test turned out so well that teletype will become an integral part of the communications used on the inland waterways. If this does in fact become the case, the problems of frequency assignment should be dealt with now, and not after the frequency becomes so congested that communications is impossible. There did not appear to be any problems arise by using 100 words per minute over 60 words per minute. The traffic was handled so much faster that we consider the 60 words per minute speed only to be a hindrance. All the other communications systems at WFN, such as, TWX and closed circuit teletype are also 100 word per minute systems. If WFN can be assigned its own teletype frequencies, without having local interference, we are certain that teletype will become our priority means of handling all but telephone interconnect traffic. In line with the assignment of frequencies, WFN would like to request that it be permitted to operate teletype on the 6455 KHz frequency already assigned for sideband communications. Since this frequency is in fact in the teletype band, we see no reason why it could not and should not be assigned as such. The system on the vessels communicating with WFN would be a selective digital calling system. The keyboard will feed a buffer storage unit, that has up to 1000 characters storage capability. This storage unit will hold the traffic until WFN calls for it. This will eliminate the inability of the captain to type at the 100 word per minute speed, thereby handling the traffic faster and keeping the frequency in use for less time. Due to this type of system being installed, we request that simplex frequencies be assigned. We can not think of any case where duplex operation would have an advantage over simplex operation. At the present time WFN is assigned the frequency of 6838.5 KHz and 4614.0 KHz. The M/V Joe Pickering is assigned the frequency of 6353.0 KHz and 4171.0 KHz. This puts the transmit and receive frequencies at least 500 KHz apart in each case. We find that the receiver sensitivity suffers in this case, and know of no transceiver on the market that can operate efficiently with the transmit and receive frequencies so far apart from each other. This is another reason we feel that simplex operation would best fit our needs. Equipment used at WFN Transmitter - Communications Associates Model CO-70-MS with the CL-35 Linear Amplifier Converter - Communications Associates Model CF-8 Telepriner - Teletype Corp. Model 28 Antenna - Half Wave Dipole Power Output - 800 watts Frequency - 4614.0 KHz transmit 6838.5 KHz transmit 4171.0 KHz receive 6353.0 KHz receive Points of Communications - Jeffersonville, Indiana to Cairo, Illinois Equipment used on M/V Joe Pickering KVBH Transmitter - Communications Associates Model CA-35-MS Converter - Communications Associates Model CF-8 Teleprinter - Kleinschmidt Model AN/FGC-80 Antenna - Shakespear Model 222 34 foot Vertical Whip with CU-35 antenna coupler Power - 150 watts Frequency - 4171.0 KHz transmit 6353.0KHz transmit 4614.0 KHz receive 6838.5KHz receive Points of Communications - Cairo, Illinois to Jeffersonville, Indiana ----------End of WFN Letter to the FCC--------- WEBMASTER COMMENTS: This letter is of 1973-74 vintage and was provided by the WFN Station Manager at that time, Robert Grau, K3ISS. Thank you, Bob. In contrast to the High Seas and Great Lakes where duplex operation was the norm all of the inland waterways SSB communications were on simplex frequencies with both WFN and the towboats using 6544.0 KHz at that time. Since duplex frequencies were used for these tests they must have been assigned by the FCC temporarily for the tests. In a message to me Bob reported on the outcome of the tests: "Nothing much came out of using RTTY on our tow boats. During a captain's meeting held in Jeffersonville the captains turned down using RTTY thinking it would take too much time."