Problem Interference
Dear Gary: In Charles Wood’s article in Issue 43 on the DTC 100 vs. DISH 6000, I was very happy to see that he mentions the "annoyance that is common to all owners of satellite HD systems, and that is momentary dropouts of audio or audio and video." Well, I thought I was the only person who has experienced this problem. I have had it for a few years, even prior to HDTV, which I have also a 60-inch ProScan. But, the dropout problem is something that should be corrected. It has to do with over-the-air interference. It started to be intermittent between the hours of 4pm and 8:30pm but now has become quite common around the clock. I have a 12-foot paraclipse dish and have had satellite TV for over 12 years. There was no problem until recent years. I bought a microwave filter ($700) and that worked for a while but does absolutely nothing now. I know that the problem is interference because my satellite installer (DJL Satellite) put a spectrum analyzer on the lead-in and whenever it peaked or spiked, the picture would go out. I also contacted the DWP and they sent someone out to see the readings on the spectrum analyzer. He said whatever it is, it is illegal. But he was unable to trace it to the source. As you are probably aware, the FCC moved from their Long Beach, California headquarters years ago, after federal funding dried up for them. When you phone them, you get their Virginia offices. Due to lack of funding they can no longer solve these types of problems. I have used all types of surge protector plugs, including the new one from Monster Cable®. Quite expensive, but the spikes still come through. Even when I play a DVD (Toshiba progressive scan) the picture flickers. The interference comes down the line into the TV making the picture flick off and on several times. When I read Wood’s article it is apparent that this interference is all over the area. I was pleased to see he is in California, where this is happening. I suggested he use a spectrum analyzer on his system to see if it shows spikes when the picture goes out. We have to get together to solve this thing. I was transferring a 1-inch tape to 3/4-inch and when the Sony player tape ended I picked up a voice from a radio station, coming through the Sony. My landlord said it was from a Cuban radio station in Florida. Somehow they are retransmitting this signal all over Los Angeles, or even California, illegally. Could this be the problem? And the interference seems to come at the same time on a daily basis. I thought it may be the new Metro Rail system but it was occurring before it was running on a regular schedule. Please investigate and try to solve this problem.
Via E-Mail
Contributing Writer Charles Wood
Thanks for your e-mail. After reading your description of the reception interference difficulties you are experiencing, it seems likely that you’re experiencing not one but several different types of interference. Additionally, the dropout problems that were a problem on the HBO HD feeds on C-Band, and passed through to DirecTV® and DISH Network™, were data-related problems. Numerous viewers have observed the dropouts simultaneously nationwide so they were not a result of local interference. These problems seem to have lessened to a great extent recently, indicating that some action has been taken at the point of origination (HBO). Another dropout problem that some DISH Network users were experiencing was the result of switching their receivers to 720p instead of 1080i in the mistaken belief they would improve the motion artifacts that are a fact of life with interlace. Not only did they really not improve anything, their doing so tended to create an induced dropout problem. One of your descriptions of interference seems to be that of classic terrestrial microwave interference on C-Band. I believe that you could be receiving this interference now (you indicate it wasn’t a problem until more recently) as a result of a new microwave link being placed into operation that is transmitting energy in your direction and it is getting into your dish and being reflected by the feedhorn. The interference might also be coming from television helicopter news crews. I’m not sure what frequencies TV stations use to link the signals back to their studios but I seem to recall they are in or around C-Band satellite frequencies. Do you notice this interference on all satellite locations or just when pointed to certain satellites? I also personally observed that digital noise being radiated by computers and other AV components, created serious problems with a Uniden 4800S which I owned at one time. On the other hand, neither my GI 4DTV and HDD200 or my Chaparral Monterey have any difficulty in rejecting this type of interference. Lastly, your RF interference from the Cuban radio station is strange, to say the least. I suspect that perhaps the station is audio streaming on the Internet, someone in L.A. is picking it up and rebroadcasting it with an illegal transmitter. Admittedly, the FCC has virtually zero funding any more for tracking down illegal RF activity but I think if you sent the FCC an e-mail and copied your local U.S. Representative and/or Senator, you might get some action. I think the identification of the interference as Cuban-sourced might get some attention in Washington. If you have "clean power" feeding your system via surge protectors, power line conditioners, etc., then you’ve probably eliminated the power line as a source. If you still find interference riding in on the power lines, then you may wish to consider a conditioner that actually converts the incoming AC to DC and back to pure very high quality AC (no outside waveforms or noise riding on the AC waveform). You may know but I’ll remind you that most surge protectors don’t really clean up the AC very much. They protect against spikes but the MOV devices aren’t capable of eliminating noise on the incoming AC. Finally in closing, I actually live in Utah. I’m pretty fortunate in that I don’t have much airborne RF interference hitting any of my satellite systems. I wish I could offer more solid solutions but the types of interference you describe can be very difficult to isolate and trap. As an example, one commercial satellite downlink/uplink site nearby in Salt Lake City suffered from terrestrial interference so badly they dug a huge pit to install their 30-foot dish below the surface of the ground and a high fence around their property to further shield it from interference. I wish you good luck in solving your problems. Please let me know how you progress.
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