Mobile Station RFI Kits

Coax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHz

CMNF-500-50

Coax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHz CMNF-500-50

For coax feed lines with receive and transmit signals, you will love the small size, wide frequency range and excellent attenuation of common mode noise interference

- Reduces broadband common mode receiver noise* picked up on the outside of the antenna coax feed line.

- Wide frequency range works on all brands of radios and coax fed antennas from 1-60 MHz

- Common mode noise rejection up to -38 DB (3-6 "S" units) depending on frequency

- Simple plug & play installation: plug a short jumper from the CMNF-500HF to your radio and plug the feed line into the other SO-239 CMNF-500HF input. Either connector can be input or output. Rated at 500 watts PEP, 50 ohm input/output

- will work with Bias-T antenna switches and will pass DC voltage from input to output with no attenuation

* not effective for noise from AC power lines or noise received directly by antenna

Installation Note: For best results, and to reduce co-interference between choked and unchoked coax feed lines with multiple antennas, ALL antenna feed lines entering the radio room need to have a separate feed line choke particularly if they are at a different frequency then HF, like VHF or UHF.

If you use a antenna switch for multiple antennas in the 1-61 MHz range, place the CMNF-500HF in the "common" line of the antenna coax switch and the receiver.

If you use a higher powered transceiver over 500 watts PEP or use an amplifier, consider the CMNF-1500HF (1.5KW PEP) or CMNF-5000HF (5KW PEP) placed at the output of the amplifier.


This product was formally named CMNF-1/1M prior to October 31, 2017


$59.95 In stock
UPC:Does not apply
Brand:Palomar Engineers
MPN:CMNF-500HF
Country/Region of Manufacture:United States
Filter Power Rating (PEP watts):500
Choking Impedance (ohms):1000-6500
Common Mode Attenuation (db):21-38 db
RFI Suppression Range (MHz):.1-60
Insertion Loss (db):.025
# Ferrite Filters:3
Enclosure Size (inches):3" x 2 x 1"
Typical Use::Coax Noise filter at radio end of coax
Coax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHzCoax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHz
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.