Mobile Station RFI Kits

Off Center Fed (OCF) antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center. For example, the Palomar Engineers 4010 OCF is a very popular antenna and consists of an off center fed dipole with sides of 55 feet and 11 feet and it will work all bands from 40-6 meters.The End Fed OCF uses the same dimensions but the wire section is 55 feet as in the OCF and the coax outer braid is used for the “other” short side of the OCF dipole. We place a choke on the coax at the 12 foot distance from the matching unit and we essentially have an OCF antenna with its great frequency range, but with only a 55 foot wire length instead of the 66 feet required by the regular OCF. You feed the antenna from one end which may be more convenient for some installations. This antenna will work on 40-30-20-17-15-12-10 and 6 meters. Most bands are under 3:1 SWR and easily tuned by your transceiver’s internal antenna tuner or external tuner used with an amplifier. (see BULLET-4006 for specific details and SWR curves).

These antennas are MUCH BETTER PERFORMERS than End Fed Half Wave antennas because they work the WARC bands, DO NOT HAVE A DANGEROUS HIGH VOLTAGE at the antenna connection and are SHORTER to fit in smaller spaces yet provide more band coverage up to 6 meters!

Mobile RFI kits work two ways: They suppress RFI from on board computers and other sensing/control devices in your vehicle that may cause your radio to be a VICTIM of RFI, and second they suppress RFI generated by your radio as a SOURCE which may affect your on board computers or other devices.  Mobile operations of HF radios (1-30 Mhz) tend to experience more RFI effects than VHF/UHF mobile stations.  If you have both HF and VHF installations in your vehicles, you may need both kits.

To address separate solutions we have developed two separate RFI kits: one for HF (1.8-300 MHz) mobile installations and another for VHF/UHF (30-1000 MHz) mobile installations.  Each kit uses the appropriate ferrite mix for the frequency range desired.