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![]() HFguy wrote: Are those two people open to hearing about BPL interference to international shortwave broadcasting? Most interference to international shortwave broadcasting is reportable and, in theory, enforceable. Broadband Over Power Line, both access and in-premise BPL, can and does cause interference to HF and low-VHF reception. There are several types of BPL, and each has its own unique characteristics, but all types of BPL have some characteristics that help identify it. o The most important factor to diagnosing BPL is to determine that it is in operation in your area. The FCC mandates that the BPL industry maintain a database of BPL locations and contact information. See http://www.bpldatabase.org. Don't do too many searches, though, as each search after your first slows the site way down. If you have any complaints about the BPL database, contact the FCC about them. ARRL also maintains a BPL database page at http://p1k.arrl.org/~ehare/bpl/ex2.html. It contains information from a much broader range of sources, and has much added value such as hyperlinks to interference reports, etc. Contact for any comments or questions about the ARRL's BPL pages. o BPL occupies a significant swath of spectrum. If you were hearing a narrowband noise, perhaps across 30 kHz of a SW band, or noise spaced every 30 kHz across a wide range, this is not BPL. It fully fills any spectrum it occupies. o BPL can consist of close-spaced, usually digitally modulated carriers, typically every 1.1 kHz, or it can sound like broadband noise. If noise you hear has a strong 120-Hz component to it, it is still related to power lines or electrical devices, but it is not BPL. o In its use of spectrum, the onset of BPL vs spectrum is rather abrupt. For example, you could be tuning up the bands, and at 4 MHz, the band is clear, but by 4.1 MHz, the noise has increased dramatically, and stays that way over a few MHz (typically), then disappears in the same way farther up the band. It's not uncommon for BPL to occupy several blocks of spectrum over tens of MHz. If your location and noise match the above, you will probably also see BPL equipment on your power lines. Look for new boxes and new BPL couplers on the lines near your house. The ex2.html site listed above has links to pictures in a number of the entries, as does the ARRL BPL resource page at http://www.arrl.org/bpl. If you do have BPL intereference, most of the procedures outlined in http://p1k.arrl.org/~ehare/bpl/complaints.html also apply to filing complaints about the reception of international shortwave broadcast. Unfortunately, although administrations are required to write regulations to protect the reception of broadcasts from other countries, the reception of shortwave broadcasts within the US probably doesn't enjoy such protection. Most SWLs probably listen to more than just the US religious stations, so if you do have SW interference, focus your complaint toward the international stations. The US stations could be interested in receiving your reports, though, as they may at some point want to speak out about international concerns about BPL. Your ability to listen to Amateur Radio stations should also be protected, as is the reception of WWV, etc. Unfortunately, you probably cannot claim harmful interference to the reception of utility stations that are not intended for reception by the general public. Your initial complaint about BPL should be sent to the operator of the BPL system. In many cases, you won't know whether this is your electric company, or a separate ISP, so the most certain way is to start with your electric company. Send informational cc's to the FCC addressess listed in the complaints.html URL. In all cases of interference, it is generally important to identify it correctly. Although power-line noise can also cause interference, and it, too, should be reported to your electic utility company and FCC, it should not be confused with BPL. Every little burst of noise that may occur for a few seconds, or every single computer "birdie" is not necessarily harmful interference as defined by the rules, but "legal limit" broadband signals will be S9 or greater across tens of MHz, typically over a large geographical area. Although ARRL's cooperative program with the FCC is specifically focused on Amateur Radio, the information on ARRL's web page about power-line interference may also help the SWL better understand power-line noise and know how to proceed with complaints. Those complaints should be directed to the FCC Call Center in Gettysburg, PA. See http://www.arrl.org/tis/info/rfi-elec.html. Interference from other devices can also affect radiocommunications. ARRL's general RFI pages at http://www.arrl.org/tis/info/rfigen.html points to a wide range of free information about interference. Inquiries about interference involving Amateur Radio can be directed to . BPL-related questions can be sent to me at . Ed Hare, ARRL Laboratory Manager Tel: 860-594-0318 |
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