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ARRL Volunteers Find, Fix "The Ditter"
NEWINGTON, CT, Jul 28, 2000--ARRL staffers were greeted the morning of July 24 with reports of a continuous string of CW dits near 14.008 MHz--heard throughout North America over the weekend. Initial reports gave conflicting beam headings, but when FCC staffer John Reiser, WQ4L, called ARRL to report his observations, things started to happen.
Reiser facilitated an FCC DF trace to the San Diego area. The ARRL San Diego Section leadership was notified, and Section Manager Tuck Miller, NZ6T, coordinated local hams in a close-range DF effort. San Diego section Official Observer Coordinator Bill Sallee, K6TWO, took several field readings. At one point, when he'd narrowed the location to within two miles, the signal abruptly disappeared. The ARRL Monitoring System also was alerted. It was confirmed that this was a normal CW signal, not a return of a broadband "woodpecker" type of intruder. All concluded the most likely cause was a turned-on, unattended rig with a grounded dit paddle on the keyer.
Dialing around the bottom edge of 20 meters early on July 26, IARU Region 2 Monitoring System Coordinator Martin Potter, VE3OAT, heard the ditter once again, this time near 14.026 MHz. Flipping on his oscilloscope, Potter found that the signal had an identical period, duty cycle, and beam heading as the one heard earlier. He notified ARRL Headquarters, and the San Diego hams picked up where they'd left off.
Equipped with a DF antenna and a battery-powered Elecraft K2 transceiver, Sallee started taking field readings, which drew him closer and closer to the coast, where the heading reversed. Sallee reports that he ultimately found the apparent source in the oceanfront community of La Jolla. He says the woman who answered the door said her husband was a ham and allowed Sallee to take a look at the station. Sure enough, a stuck dit paddle was keying a powered, unattended rig, which Sallee disabled.
Sallee theorizes that heating and cooling within the ham's uninsulated shack and a combination of corrosion in the keyer paddle's pivot mechanism and close dit contact spacing contributed to the contact's migrating to a closed position. He said the ham later told him that he'd been operating on 14.007.5 MHz on July 21 but did not return to the shack until Monday afternoon. "He remembers listening to a CW contact on 14.026 but did not transmit," Sallee said. "He then left the shack unaware that by leaving the rig on, he would fall victim to unattended transmission when the moisture and temperatures began to change."
Sallee says the ham, whom he did not identify, "was most embarrassed."
"I really felt sorry for him and assured him that public hangings were no longer in vogue," Sallee said. "He said he had learned a valuable lesson about disabling a rig that will be unattended."
ARRL Regulatory Information Specialist John Hennessee, N1KB, points out that Part 97.7 of the FCC's rules require a control operator for each amateur station. "Unless there are procedures for remote or automatic control, a control operator must secure the station before leaving it," he said. Simply flipping the off switch or disconnecting the power source are simple ways to comply with §97.7 and prevent unintentional transmissions, Hennessee said.
But all ended well, and Potter was among several who sent deserved kudos. "Congratulations to both the ARRL Monitoring System and the San Diego Field Organization," he said. "A fine example of quick reaction and good, solid work on this unintentional emission. You guys are an inspiration to everyone."--Brennan Price, N4QX
Page last modified: 10:49 AM, 28 Jul 2000 ET
Page author: awextra@arrl.org
Copyright © 2000, American Radio Relay League, Inc. All Rights Reserved.
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