RFI Common Mode Noise Filter Kits for FLEX RADIO Antenna Genius Antenna Switches - Isolate Non-Selected Coax Braid Noise!
Coax antenna switches generally only switch the center conductor of the coax and all the coax braids remain connected in parallel summing the common mode noise off ALL coax lines onto the coax selected - this means you may be picking up common mode noise from coax lines that are not even connected to the coax antenna selected. The only practical solution is to isolate the coax braids from each other BEFORE they connect to the antenna switch as shown in the picture for a FLEX RADIO Antenna Genius 8 port switch or just a simple 2 position antenna switch.
This product listing is for antenna switches from 2 - 8 antennas. Each switched line needs a common mode noise filter prior to being connected to the switch. In some cases you can use a double male barrel connector to attach the filter to the switch or you may need a short jumper cable.
We offer a low power filter (CMNF-500-50 up to 500 watts PEP and up to 46 dB of common mode noise suppression per line) or a high power (Maxi-Choker, MC-1-1500 up to 1.5KW PEP and up to 42 dB of common mode noise suppression per line) and 2-8 ports of antenna switch. If you use a dummy load for one of the switched ports you do not need a filter for that port. Each filter has a range of 1.8 to 61 MHz (see individual listing on this website for specifics).
Picture shown is 8 port FLEX RADIO Antenna Genius at AK6R with one dummy load and 7 antennas. Inputs to Antenna Genius is from TUNER GENIUS with SO2R option.
This kit also includes 1/2 snap on filters for the ethernet line and the 12 volt power supply and two 1" snap on filters for the RF input lines (1/2" ID RG-213 shown and also works with 1/4" ID RG8-X/RG400, etc.).
Also make sure you connect a good RF ground to the transceiver ground post.
Note to Flex Radio users: Use snap on ferrites for firewire cable, speaker cable and mic cable, Ring ferrites for Antenna output and DC power.
For additional RFI suppression, use a feed line choke at the antenna to suppress common current on the coax feed line – see our store for feed line choke alternatives for use at the antenna.
If you use a linear amplifier we have RFI kits for linear amplifiers that help suppress RFI in your shack or in your neighbor’s house.