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 wo organizations have filed comments with the FCC that augment previously expressed worries about potential interference from and to Broadband over Power Line
(BPL) systems. Picking up on the "grave concerns" the Federal Emergency Management Agency
(FEMA) http://www.fema.gov
expressed over BPL December 4, the nonprofit Disaster Preparedness and Emergency Response Association
(DERA) http://www.disasters.org called on the FCC to require impartial BPL field testing as well as additional public comment and full and open public hearings.
"DERA concludes that serious interference to and disruption of critical emergency communications systems in several licensed services throughout North America would almost certainly result from BPL implementation as currently proposed," DERA said. Endorsing the earlier FEMA remarks, DERA said proposed BPL systems don't just pose a risk of interference, they've already been shown to "actually cause harmful interference to licensed radio services."
Meanwhile, the Amateur Radio Research and Development Corporation (AMRAD) has filed additional test data with the FCC to support preliminary findings suggesting that BPL systems are susceptible to interference from even modest Amateur Radio HF signals. AMRAD said its newest data demonstrated that amateur operation in the test neighborhood would cause many homes to lose their Internet service.
"At least an area out to a radius of 0.51 miles from the transmitting station could have their Internet connection interrupted," AMRAD said. "Closer-in homes would almost certainly have their Internet service interrupted." For its RF susceptibility experiment, AMRAD used the Potomac Electric Power Company system test site. It features a mid-1960s vintage home with unshielded interior electrical wiring and overhead power lines.
AMRAD found that at a distance of just over one-half mile, data transfer ceased in the face of a 100-W signal on 3980 kHz from a mobile transmitter. Adjacent to the test property, AMRAD said data transfer ceased in all but one instance at a transmitter power of just 4 W in the BPL operating band of from 4 to 21 MHz.
The ARRL hopes to complete an independent BPL engineering study early this year. It will explore how BPL might affect HF and low-VHF amateur operation as well as how Amateur Radio operation could affect BPL systems.
In related news, BPL equipment manufacturer
Amperion, Inc recently announced an "industry first" by successfully testing its high-speed "Connect" system on 69 kV transmission lines. Typical BPL systems have employed medium and low-voltage lines to deliver broadband and Internet access. Amperion said its tests, performed in conjunction with American Electric Power, demonstrated multi-megabit data transmission to a distance of nearly one mile without the need for a repeater. There's more information on Amperion's Web site
http://www.amperion.com/press.asp?pid=89.
Additional information about BPL and Amateur Radio is on the ARRL Web site
http://www.arrl.org/tis/info/HTML/plc/. To support the League's efforts in this area, visit the ARRL's secure BPL Web site
https://www.arrl.org/forms/development/donations/bpl/.
-From ARRL Letter January 2, 2004
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or those of you who don't know, I had a small stroke on Christmas day. The only effect seems to be the loss of some of my peripheral vision on the left. Further tests indicate some artery blockage. I'll know more about this later.