============================================================================== K E N W O O D >>> A M A T E U R R A D I O S E R V I C E B U L L E T I N <<< ============================================================================== Kenwood Service Centers Kenwood Service Corporation Kenwood Service Center, East 2201 East Dominguez Street 829 Lynnhaven Parkway, Suite 130 Long Beach, California 90801 Virginia Beach, Virginia 23452 Telephone 1-310-639-5300 Telephone 1-804-340-1702 ============================================================================== BULLETIN # 4 MODEL: TS-520 SUBJECT: AM BROADCAST INTERFERENCE WE HAVE FOUND A FEW INSTANCES OF CUSTOMERS WHO LIVE NEAR AN AM BRADCAST STATION HEARING THAT STATION ON THE 3.5 MHZ BAND OF THEIR TS-520. SHOWN BELOW IS A FILTER THAT MAY BE INSTALLED IF THIS OCCURS. |------------------------------| | RF UNIT | | NAT |--- | GND |- | | ---------------| | | | | |---------------| | | | L1-C1 (ADD IN LINE) | | TO <------------------| S-9 A SUGGESTED LOCATION FOR THE FILTER IS ON A SMALL TERMINAL STRIP THAT IS THEN MOUNTED ON A MOUNTING SCREW OF THE RF UNIT. THIS SCREW IS LOCATED AT THE FRONT CORNER NEXT TO THE VFO. THE CABLE BETWEEN S-9 (WWV SWITCH) AND TERMINAL -NAT- OF THE RF UNIT IS REMOVED FROM TERMINAL NAT AND CONNECTED TO ONE SIDE OF THE FILTER. A SHORT PIECE OF RG-174U IS THEN CONNECTED FROM THE OTHER SIDE OF THE FILTER TO THE TERMINAL -NAT-.THIS SHOULD PREVENT THE AM BROADCAST INTERFERENCE. COMPONENT VALUES ARE AS FOLLOWS: FREQ. L1 C1 1300 KHZ 22 UH 680 PF 1000 KHZ 100 UH 220 PF 700 KHZ 100 UH 470 PF