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.
We specify impedance ratios as an output to input ratio where the output (or load) is given first and the input is given second (e.g. 100:50 (2:1) would mean a 100 ohm output and a 50 ohm input; a 25:50 (1:2) would mean a 25 ohm load and a 50 ohm input). Most all products use a 50 ohm input unless otherwise specified.
We have products that are available as kits for the do-it-yourself (DIY) person or fully assembled and tested units for the “Plug & Play” crowd.
Our impedance transformers are available using two different topologies: Binocular cores or toroid cores with multiple turns for increased effectiveness and wide band frequency transformations. We utilize single and multiple core transformers using high order windings when needed to extend product performance.
We rate the power ratings as watts PEP (Peak Envelop Power) with standard duty cycles for various modes. To determine the PEP rating required for your needs, see: Choke & Transformer Power Ratings
This website page serves as a link page to the frequency ranges of our impedance transformers configured as either baluns or ununs. You can click on a picture to go to the specific page about the products described in the picture.