karn@eagle.UUCP (08/09/83)
With the launch of Amsat Oscar-10, problems have arisen with terrestrial interference to the Mode B (145.8-146.0) downlink. Many hams have become accustomed to operating FM simplex in this range. However, the ARRL 2-meter bandplan designates the 145.8-146.0 mhz range for Amateur Satellite use only. Most amateurs gladly move to different frequencies once they are informed about the satellite and why the segment needs to be kept clear. In my own case, the local radio club had its simplex net frequency on 145.800 mhz. After I announced that Oscar-10 was operational, the club eventually moved to a new frequency. Not only that, I was invited to give a talk on AMSAT at a special club meeting! However, there do seem to be a small number of amateurs who, despite having been politely informed that they are interfering with satellite communications, refuse to move out of the downlink passband. For this minority, there may be legal recourse. On page 63 of the August QST, the Washington Mailbox column quotes an April 27, 1983 letter from the FCC to a repeater council: "The only national planning for Amateur Radio Service frequencies that has come to our attention is that done by the American Radio Relay League. The 1982-83 edition of the ARRL Repeater Directory lists over 5600 stations in repeater operation all over the United States and Canada. In view of this widespread acceptance of their band plans, we conclude that any amateur who selects a station transmitting frequency not in harmony with those plans is not operating in accord with good amateur practice. [For example] The ARRL Repeater Directory lists the frequency pair 144.83/145.43 MHz as a repeater channel. Therefore, designation of the channel by the regional frequency coordinator in [an] area is in accord with the ARRL national band plan." The article goes on to state: "The bottom line is that if stations transmit on frequencies 144.83 or 145.43 (to use the Commission's example above), in a manner that creates interference to coordinated repeaters, then sufficient cause would exist for issuance of an Official Notice of Violation of Section 97.78. And, such operation could mean an additional Notice for deliberate and malicious interference (97.125)." If you are having problems with local interference to Oscar-10 in your area, I would recommend that you first try the diplomatic approach. If you're lucky (as I apparently have been) and get a chance to explain what's going on, you might even find a few of the people asking furtive questions about 70cm antennas, amplifiers, etc! Only when all else fails should you bring up the fact that the FCC appears willing to back up the ARRL band plans. Good luck. Phil Karn, KA9Q AMSAT Asst VP, Engineering