These are simple pigtail common mode chokes consisting of RG58 cable with a PL259 on one end and SO239 on the other.  Approx 5-6cm of space between the core and the connectors.
 
The standard widing is 12 times around a 240-43 Toroid core.  Maximum power is 400w.
 
If placed between you tranceiver and antenna you will get sufficient choking effect to isolate your Tranceiver from currents or noise passing on the outside of your coax.
 
If you have purchased one of our EFHW or EFRW antennas you should position the toroid at the receiver and and then have the remaining coax going to the antenna transformer.
 
 
Important: Connector Usage Instructions
 
While we take care to ensure all SO239 (female) connectors are securely attached and sealed to the coax using glue-lined heat shrink, we have received returns where the SO239 connector has been damaged by twisting. Please note that this is an incorrect connection method.
 
SO239 connectors are not designed to be rotated. To connect a PL259 (male) to an SO239 (female), simply insert the PL259 into the SO239 and tighten the outer collar only. Do not twist or rotate the body of the connector, as this will damage the internal contacts of the choke.
 
Please be aware that returns and refunds will not be accepted for SO239 connectors damaged through incorrect use.
 
NOTE
These are built to order and may take a day or so longer than quoted for dispatch.