Interference HOW-TO Page 1 - Page 2 - Page 3 - Page 4 - Page 5 - Page 6 Filters This page covers HOW-TO install some helpful TVI/RFI-filter at the interfered equipment. This is the last, and hopefully not needed way to solve your problems with TVI/RFI. It involves the interfered equipment and some easy to install filters,- Installations of these filtes must of cause be done in total co-operation whith the owner of the interfered equipment. - Powercables and RFI-Problems - You can use toroid-core for blocking RFI-problems picked up via the Power-cord to any interfered electrical equipment. Before doing this,- you should concider trying to apply an Toroid-core onto the AC-Power cord on your Power-Sypply at your Transmitter. Installation of an Purple-4C65 'AMIDON' Toroid core on AC-Power cord To use the Toroid-core to block RF-Interferance going in to any electrical equipment,- the Procedure is the same as when using them at the transmitter side. Make a coil of the AC Power-cord onto the toroid core,- The toroid core need to be made of proper ferrite material color-code with purple or pink. (Code 4C65 or 4A11) You have to make som experiments to get the right numbers of turns,- should be about 6 if working on 27MHz. (Lower frequency = more turns) Note! The core/coil should be placed on the power-cord as close to the equipment as possible!. - Ferrite Beads - 'Beads' is an smaler type of 'toroid' core,- The beads is made specially for RFI-Blocking use,- In most cases the beads is made easy to apply to any Power-cable,- Telephone-line or Stereo-Speaker cable. The beads is installed to 'Block' any RF-Signal that may be 'Leaking' from your transmitter to, or picked up by the AC-Power system in your house. In general the beads should be installed as close to the Intake on the interfered equipment. - Telephones and RFI-Problems - To block RFI in telephone equipment, the beads is used on the thelephone line that connects the interfered thelephone. Sample Ferrite bead - Closed/Open Ferrite bead - On AC-Power coord Ferrite bead - On Thelephone line - TVI Filter - High-Pass Filters s.a. Micro-Tronics model HPM50101 is used to block unwanted radio signals to enter any Antenna input. (An interfered Television Set) The High-Pass Filter is attached on your TV-Antenna cable, close to your TV-Set, It blocks any signal beneath an 'fix' frequency. example: Micro-Tronics model HPM50101 got a 'Stop-Band' going from 0-80MHz whitch make it sutable for use to 'Block' RFI/TVI from an Transceiver-Set. The Web-Site for Micro-Tronics. - NOTE! - You can-NOT use beads to block Radio-signals on an antenna-cable to a tv-set,- it will also block your TV-Signal!! High-Pass Filter Micro-Tronics model HPM50101 Page 1 - Page 2 - Page 3 - Page 4 - Page 5 - Page 6 *** End of page *** <--Back