TV Interference

It always seems to happen. You have earned your license, spent your bucks on that new dualbander, and finally, your ticket comes in the mail. You decide to get on the I0-70 repeater for a chat, and then, the phone rings. Its your neighbor down the street asking, "Are you talking on your ham set?" You say that you are, and he tells you that he is unable to watch the auto race on ESPN. Because you don't know better, you agree to get off the air until the race is over. While you set there, unable to use your radio, it is a big mystery that something like this has happened. You wonder how it is .that only cable channel 18 is involved. Here is what's going on: When cable TV began, it used channels 2 through 13. These are the same channels that any U.S. standards TV will tune. These are known as the VHF channels. (54-88 and 174 -216 Mhz) As cable TV grew and satellite delivered programming became available, the cable companies needed more channel space. They started using the frequencies from, 108 to 174 Mhz. This is called the midband Since then, many systems now occupy the superband, that is, 216 Mhz and above, The 2 meter ham band is allocated 144 to 148 Mhz to the Amateur Radio Service on an exclusive basis in this region. (144-146 worldwide) The cable industry decided that cable channel 18 ( not UHF 18, WETM) would be from 143 to 149 Mhz, with the video carrier at 145.25 and sound carrier at !48.75 Mhz. The cable operator has every right to place stations in the mid-band ur where ever, as long as their signal does not leak from their system. The FCC does not give the cable operators any privileges to any over the air frequency use. This means, when someone dials up cable channel 18 to watch ESPN in Corning, or TNN in Elmira, they are actually tuned to the 2 meter band. Coaxial drop cables are shielded, but not that wall shielded. When you add in connectors, splices, self done hookups, this spells viewing disaster for the TV'. watcher, and unhappiness for the ham. What do you do? First, don't panic, secondly do not get off the air. Remember that you, as a licensed Amateur Radio operator have exclusive use of that frequency. You are not obligated to share it with your neighbors or the cable TV operator. First, tell the neighbor the reason he is having difficulty with his cable TV reception, You might want to keep a copy of this article to pass around. Next, tell the neighbor that the cable company is responsible for good reception and that you will call them and make them aware that there is a problem. When you call, you might ask to speak with the chief technician, as the people at the desk usually aren't technical people. Leave the rest to the cable operator, Its their business decision to put a popular channel on a channel that is assigned to ham radio. In Corning, the angle of attack is to use double and triple shielded drop cables. They will also put all new connectors, remove splices where ever they can. They also give the customer a double shielded cable to attach between their VCR and TV set. One last note. How the cable company handles the complaint is very important. You have probably spent years building good relations with your neighbors. They help you, you help them, you drink their beer, etc. This all can be ruined by lines on their TV. Make it known to the cable company that the interference is their problem and that they must take full responsibility for using that channel. They must tell the customer that it is not the ham operators fault. They should advise the neighbor that the ham is not at fault and should not be hassled over the difficulty. Whew! It looks like this months technical article isn't completely technical. However, in "such cases, it is important to know how to deal with others. By the way, if you operate the 222 Mhz band, you will see wiggles on channel 24 and if you operate the 440 band, those are channels 60 and 61.

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