sanders@menlo70.UUCP (09/25/83)
I have a Liberty Freedom 100 terminal at home that scrambles channels 2,4, and 5 on my housemate's TV. I tried putting a high-pass filter on the antenna (Radio Shack $1.99 special) with no success. Any other - preferably cheap - suggestions? (Someone please tell me if there is a better group than net.misc for this.) -- Rex ucbvax!menlo70!sanders
parnass@ihuxf.UUCP (09/27/83)
In response to the following item: --------------------------------------------- I have a Liberty Freedom 100 terminal at home that scrambles channels 2,4, and 5 on my housemate's TV. I tried putting a high-pass filter on the antenna (Radio Shack $1.99 special) with no success. Any other - preferably cheap - suggestions? (Someone please tell me if there is a better group than net.misc for this.) ---------------------------------------------- Sometimes, electronic "noise" is conducted from the device, in this case a terminal, into the power lines. Try using an AC line filter between your terminal and the AC power outlet. These filters are now available by mail order or in Radio Shack. Many come in fance cabinets, with all kinds of pilot lights and switches. They are very overpriced. Radio Shack sells a hermetically sealed module for less than $10. You can install it in a metal box and put the connectors on it yourself. These external filters are always a compromise. A better way is to mount these filters in the offending device (if space permits). The FCC has set two sets of standards for electronic equipment. These standards, class A and B, specify maximum permissible limits of electromagnetic radiation over different frequency ranges. One class is for equipment sold for use in business. The other is for equipment sold for use in consumer house- holds. The latter is more stringent. If you borrow a terminal from work that meets only the industrial FCC standards, and bring it home, you are likely to run into the types of problems you describe. The FCC has field tested several personal computers. It found that about 30% of those taken right off the shelf do not meet the FCC radiation limit standards they are legally supposed to. I think Commodore was just fined by the FCC for selling printers that did not comply with the appropriate specifications. Welcome to the world of electromagnetic compatability! -- ============================================================================ Robert S. Parnass, AT&T Bell Laboratories, ihnp4!ihuxf!parnass (312)979-5760
fremont@hplabs.UUCP (09/29/83)
I have an IBM PC with an IBM color graphics board and a Taxan RGB-III color monitor. I get lots of tv interference (chs. 2,4,5) from the *cable* between the pc and monitor. It helped to wrap the cable in aluminum foil and ground the foil. mike