Wednesday, July 30, 2008

More On PLC Trouble in Portugal

More ominous news from Portugal via UKQRM:

Hi everybody,

I'm Joe, SWL CT0347 and CT4AN, Amateur for several decades and space telecom researcher. Thanks to the owner and moderators for giving me the opportunity to be a member of your Group.

I am very worry about the situation of using main power lines (inside houses or not) with other kind of signals not beeing 50Hz.In my country, Portugal, we have now a new big problem with that kind of signal on wide & broadband TV distribution and Internet services. A few years ago, we had our Power Company trying to establish BPL but, with the strong oposition of SWL, Ham operators and CB's, we finished their business.

Now we have PLC distribution inside the houses, for MEO services (broadband Internet, TV and phone) made by Portuguese Telecom PT, using [law suit avoidance mode -hugh] plc boxes; we are beeing all blocked on HF - all short wave listening, CB band, Amateur HF Bands, etc are getting impossible with the noise produced by those equipments, covering on full data-streem all HF from 2MHz till 35 MHz. It's a junk ... and THE END OF OUR SHORTWAVES.

Even with "gaps" on it's spectrum, located only in some Amateur HF Bands, the QRM is very-very strong, with levels of >80 dB/uV detected in a distance of 200 meters from the focus. The "notch" (when in operation ...) have 40dB of attenuation in the best, that is insuficient to preserve the noise-floor level needed for DX communications on Shortwave Bands (-110dBm minimum). That's a mess ...I would like to hear from you about your PLC experiences in your countries, with your PTT's Authorities, with your Clubs and Associations, and exchange information and possible common solutions and strifes.

J.F.// CT4AN