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 Previous: Foundation for Amateur Radio Announces 2006 Scholarship Winners |  Next: Surfin': Finding Ham Radio in Popular Culture |
REVISED Aug 3, 2006 08:33 ET
 The BPL signal can be heard along "miles of road" on 40, 20, 17 and 15 meters, one Manassas amateur has reported. |
 Manassas hams check BPL interference earlier this year: (L-R) Butch Blasdell, W4HJL, George Tarnovsky, K4GVT, and Brian Cochran, WC4J. All three have filed BPL interference complaints with the FCC. |
NEWINGTON, CT, Jul 21, 2006--A Manassas, Virginia, radio amateur who has complained of BPL interference to his mobile operation has taken issue with how FCC-mandated interference testing was performed. Dwight Agnew, AI4II, told the FCC July 20 that a testing review, carried out July 14 by Columbia Telecommunications Corp (CTC), "did not represent the Manassas BPL system at peak system loading," as the FCC had required, and therefore was not representative.
"The BPL folks' unwillingness to bring the system to peak traffic load further illustrates a lack of openness and cooperation," Agnew wrote the FCC's Spectrum Enforcement Division. "It's ludicrous that a system operator would not keep track of system loading and deny the existence of any such reporting mechanism." Agnew asserts that it's impossible to carry out objective interference testing unless the system is loaded at peak levels.
Responding in March to Agnew's complaint, FCC Spectrum Enforcement Division Chief Joseph Casey called on COMTek and the City of Manassas to take measurements at locations Agnew cited in his complaint "during the hours of peak usage of the system by BPL customers." He reiterated that directive in June.
Working with CTC's Lee Afflerbach, W3BRH, Agnew and other Manassas radio amateurs on July 14 reviewed testing done earlier by Product Safety Engineering (PSE) on behalf of BPL system operator COMTek and the city, which owns the power grid. The latest PSE testing responded to a June 16 request from Casey. He had ordered the city and COMTek to provide a "detailed report on the actions you have taken and the progress you have made in resolving the interference complaint or reducing the emissions in the area referenced in Mr Agnew's complaint to 20 dB below the Part 15 limit." Casey told Manassas and COMTek to address and "reach a resolution" with regard to Agnew's interference complaint "as soon as practicable."
In its reply to the FCC July 17, COMTek said the remedial actions it and the city took "have successfully resolved Mr Agnew's complaint." Local radio amateurs did not witness the actual system testing.
Interference Measurements Reviewed at Three Points
CTC reviewed the earlier test results at three BPL system test points picked by Agnew and the other radio amateurs. CTC subsequently reported in part, that while the BPL signal "was perceptible in at least one test location" the "very low amplitude BPL signal did not impair the reception of communications from the stations monitored during the test." BPL signals within the ham bands "were substantially attenuated" from BPL signals outside the ham bands, the report said.
The CTC report, which Manassas supplied to the FCC as a supplement to the PSE testing analysis, suggested that some interference radio amateurs have attributed to BPL "may in fact originate from other sources." Afflerbach recommended that radio amateurs in the BPL-served area employ "proven modern receiver technology" such as bandwidth filters and noise-suppression technology to minimize the effects of interference, "including any from BPL transmission."
PSE said in its report that Agnew confirmed "subjectively" that the remedial actions COMTek and the city had taken had "eliminated the BPL interference completely or reduced them [sic] to acceptable levels."
Interference Back the Next Day
 The Manassas BPL system uses Main.net equipment operating between on frequencies between 4 MHz and 30 MHz, according to the BPL database. |
Agnew said in his letter this week that monitoring un-notched BPL signals on 8 MHz indicated that system traffic during the post-testing review "was very low and did not represent peak or even normal system usage."
At one point during the demonstration, Agnew said, Butch Blasdell, W4HJL, transmitted briefly at 10 W while tuning his mobile antenna. The signal "caused the BPL system to burst data," Agnew told the FCC. "During this time Mr. Afflerbach's test receiver indicated bursts of BPL noise far greater in amplitude that the background BPL interference."
George Tarnovsky, K4GVT, one of the hams witnessing the post-testing review, told ARRL the data burst was due to RF ingress into the BPL system that caused data packets essentially to back up. When the RFI is eliminated, the data packets are sent at much greater amplitude, resulting in substantially higher interference levels. Tarnovsky said the interference "was right back" the day after CTC conducted its interference review.
"They're trying to discredit the ham radio community," he charged, referring to COMTek and the City of Manassas. "When the system is active, you'll hear it." Tarnovsky says the post-testing review indicated to him that the BPL system had not been tested at peak loading.
Agnew said the radio amateurs requested reports on the system's loading but were told by representatives of BPL equipment manufacturer Main.net and the city that no such reports existed. "We disputed this since we have seen these reports in the past," Agnew said in his letter to the FCC.
"Further testing without the system at peak loading is just purely a waste of time," Agnew said. "If the BPL folks are unwilling to share the peak loading data with us, I would like to recommend future testing of the Manassas BPL system be conducted by the FCC." To date, the Commission has not done any testing of the Manassas BPL system.
Strong Language from the FCC
 The Manassas BPL system operates over both overhead and underground utility wiring. |
The sternly worded letters in June from the FCC's Enforcement Bureau directed Manassas and COMTek to take appropriate steps to eliminate harmful interference to Amateur Radio operators. Several hams in the Manassas area have complained, some repeatedly, about severe interference from the BPL system.
The FCC also detailed what it wants the city and COMTek to do to ensure its system complies with Part 15 rules governing BPL systems and even hinted that it may shut down all or part of the system. Casey asked the city and COMTek to provide "the specific steps you will take to inform customers of a cessation of service in the event you are directed to cease operations, either in part or system-wide."
Based on earlier engineering reports the FCC had received from the city and COMTek in response to the Agnew complaint, "it appears that the BPL system is not in compliance with the Commission's emission requirements at several frequencies," Casey said last month, although none were in the amateur bands. "You are directed to take immediate steps to eliminate all excessive emissions," he said.
Other Amateur Radio Complaints Pending
Manassas and COMTek still must address specific longstanding interference complaints from Tarnovsky, Blasdell, Bill South, N3OH; Jack Cochran, WC4J, and Art Whittum, W1CRO.
The July 17 reports on behalf of COMTek and the City of Manassas complied with one of two reporting deadlines the FCC imposed. In late June,
COMTek obtained 10-day deadline extensions saying severe weather and power
outages had "wreaked havoc with testing schedules." The next reports are due by
Wednesday, July 26.
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