This paper explains a filter that ellminates intermodulation that are generated in two radio transmitting stations where having neighboring antenna each other. The STV Hakodate station changed its transmitting frequency when power up from 1kW to 5kW. AS a result, frequency difference is 36 kHz from the first radio channel of NHK. Such a narrow frequency difference is seldom found, if ever, anywhere else in transmitting stations operating at a kilowatt level. The intermodulation anticipated to be generated between these two stations were examined and tested, and goods results were obtained with a filter fabricated for this purpose. The radio transmitting station with this filter is operating in good condition.
