Coax Common Mode Noise Filter - 500 Watts PEP, 1-60 MHz
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
Typical user comment:
The filter was quite effective. Was surprised that it actually reduced the noise level more than the signal so S+N/N improved by 1.9 S units. Bill