HF Mobile Transceiver RFI and Noise Reduction Kit, RFI Range 1-300 Mz
| Quantity | Price per item | Discount |
| 2 items | $35.95 | 10% off |
| 10 items | $33.95 | 15% off |
| 100 items | $31.95 | 20% off |
Palomar Engineers RFI Filter Kit for HF Base Radio Mobile Transceivers up to 300 MHz
BUY THIS KIT NOW TO SOLVE YOUR RFI/EMI NEEDS! WORKS WITH MANY BRANDS OF HAM/COMMERCIAL RADIO RIGS
Purpose
The RFI kit is designed to be installed on your radio transceiver to reduce Radio Frequency Interference (RFI) caused by common mode current on the outside of the coax braid at the output of your radio and AC/DC power cable. Additional chokes are included to reduce common mode currents on 3 more transceiver cables including computer control, audio and another.
This kit will help reduce or eliminate:
1. “Hot mic” RFI caused by poor grounding of antennas or common mode currents from linear amps feeding unbalanced (coax fed) antennas without baluns/line isolators.
2. RFI to neighbor’s electronic devices including audio/video systems, computers, telephones, garage door openers, etc.
3. RFI to your other radios, audio/video systems, computers, telephones, etc.
A side benefit is a reduction in noise floor in your receiver depending on the amount of noise being introduced by common mode currents (which are blocked/reduced by the chokes in this kit).
These chokes use a special mix of ferrite core material that is effective in suppressing radio frequency interference from transmitters and high noise floor on receivers.
The split beads beads are easy to use, don’t require modification of the protected equipment and work in almost all cases, even when plug-in filters fail.
Use of the chokes often helps cure SWR problems between transceiver and a linear amp and between transceiver and antenna tuner or direct to antenna. The DC power line choke helps keep common mode current out of the power line which could cause interference to other devices connected to the same power line if not suppressed.
Included are the following chokes and installation guidelines:
RF Input/Output: F240 for toroid balun – 5-9 turns of RG-58/RG-8X size coax cable through center
DC Input: F240 – 3-7 turns of DC power cable
3 additional I/O cables - 1/2 snap on for 1-2 turns through center. Multiple wires can share the same filter.
For additional RFI suppression, use a feed line choke at the antenna feed point to suppress common current on the coax feed line.If you use a linear amplifier use an amplifier RFI kit for additional RFI interference suppression.
SLIP-ON FERRITE BEADS
Baluns are used to connect balanced antennas to unbalanced transmission lines (Coaxial cable) and Ununs are used to connect unbalanced transmission lines to unbalanced transmission lines or unbalanced antennas (e.g. verticals). In the case of 1:1 baluns the input is usually an unbalanced coax cable and the output load is a two terminal balanced load like an antenna. Ununs are also called line isolators, feed line chokes, and 1:1 coaxial baluns (incorrectly). 1:1 Baluns and ununs stop common mode currents (flowing on the outside of the coax braid due to skin effect) when they are located at the antenna feedpoint. They can also be used as “line isolators/chokes” anywhere along the cable to suppress flow of induced RF (antenna near field radiation and neighborhood noise pickup) which helps suppress RFI into the radio receiver/transmitter. For best results, put one at the antenna feed point connection, and one at the radio room entrance, and for difficult common mode current cases, one every 1/4 wavelength along the antenna feed line. For low (below 3 MHz) frequencies, use two 5 bead baluns in series to double the choking impedance or order the 10 bead or 15 bead version for higher choking power.