COMTek and the lab claim they did on/off testing. There were one, possibly two things wrong with what they did. First, instead of a typical radio receiver hooked to a typical antenna they used a spectrum analyzer -- which is not as sensitive as a typical receiver -- and a loop antenna -- which is far less efficient than even a typical mobile antenna. What they were actually measuring was the noise floor of their own equipment, so when they did the on/off test, it didn't have much effect. (According to their measurements the noise sometimes INCREASED when the BPL equipment was turned off!) Second, it isn't clear from the interim test report that they actually turned off the BPL "system." They may have just turned off the nearest injector. It is unlikely that they turned off all of the in-premises modems in the homes of nearby customers. Dave -----Original Message----- From: Wade [mailto:walstrom@mchsi.com] Sent: Wednesday, April 12, 2006 10:32 PM To: Sumner, Dave, K1ZZ; arrl-odv Subject: RE: [arrl-odv:13990] Manassas developments One sure fire way to determine if th eCOMTEK system is causing the interference: Shut it off momentarily and see if the interference goes away! Of course, the right thing to do then would be to leave it off if the system was indeed causing the interference. None of these actions are likely, unfortunately. 73, Wade W0EJ -----Original Message----- From: Sumner, Dave, K1ZZ [mailto:dsumner@arrl.org] Sent: Wednesday, April 12, 2006 3:50 PM To: arrl-odv Subject: [arrl-odv:13990] Manassas developments Last week, COMTek provided the FCC with less than the FCC had required in responding to the BPL interference complaint filed by Dwight Agnew, AI4II. That did not prevent COMTek from issuing a news release that made it sound as if they had been found to have a clean bill of health: http://www.comtechnologies.com/pr_20060407.htm The ARRL Web story has just been posted: http://www.arrl.org/news/stories/2006/04/12/102/?nc=1 You will find links to the COMTek response to the FCC and to the interim lab report. Ed Hare has completed a scathing analysis of the deficiencies in the lab report. Chris Imlay will be filing it with the FCC as soon as he gets a chance. Dave K1ZZ