Snap On RF Choke/Isolator - 3/4"/18.7mm cable, 5/10/15 Bead Option, 1-300 MHzProduct DetailsBrand: Palomar EngineersMPN: SNO-3/4-5Effective Frequency Range (MHz): 3-100PEP Power Rating (watts): same as coax cable ratingEstimated Insertion Loss (db): .025Input Connector Type: noneOutput Connector Connector Type: noneGround Connector (Y/N): noneEnclosure Size (LxWxH inches): noneUse for 3/4″ Cable LDF-4, Heliax(R), LMR-600, etc.
Use five split beads for 80-10 meters (3-30 MHz) or ten split beads for 160-10 (1.8-30 MHz) meters or use 15 split beads for even higher choking for 1-10 MHz.
Typical Impedance per split bead: 10 MHz: 50 ohms, 25 MHz: 95 ohms, 100 MHz: 195 ohms, 250 MHz: 322 ohms
A minimum impedance of 500 ohms is needed for 50 ohm cable or 10 times the cable impedance for other cables.
The beads clamp to the cable and may be operated as is for indoor or outdoor use. For longer life outdoors to protect the plastic covers from weathering – use electrical tape for best results or heat shrink to ensure longer life. All kits come with instruction manual which covers assembly and application tips.
As you can see from the impedance vs frequency graph, you can very effectively increase the choking impedance by increasing the number of beads on the cable.
Excellent choke size for multi-turn RG-8X or similar size cables
Snap On and Slip on Feed line chokes available in sizes to fix cables with outside diameters of 1/4", 3/8", 1/2", 3/4", 1" - check website for other size options.
Use for 3/4″ Cable LDF-4, Heliax(R), LMR-600, etc.
Use five split beads for 80-10 meters (3-30 MHz) or ten split beads for 160-10 (1.8-30 MHz) meters or use 15 split beads for even higher choking for 1-10 MHz.
Typical Impedance per split bead: 10 MHz: 50 ohms, 25 MHz: 95 ohms, 100 MHz: 195 ohms, 250 MHz: 322 ohms
A minimum impedance of 500 ohms is needed for 50 ohm cable or 10 times the cable impedance for other cables.
The beads clamp to the cable and may be operated as is for indoor or outdoor use. For longer life outdoors to protect the plastic covers from weathering – use electrical tape for best results or heat shrink to ensure longer life. All kits come with instruction manual which covers assembly and application tips.
Excellent choke size for multi-turn RG-8X or similar size cables
Snap On and Slip on Feed line chokes available in sizes to fix cables with outside diameters of 1/4", 3/8", 1/2", 3/4", 1" - check website for other size options.
Christmas lights or yard lights with switching DC power supplies are often the RFI source and a clamp on ferrite bead on the AC AND the DC side feeding the lights is needed to help suppress the switching power supply RFI noise. Suitable snap on beads are FSB31-1/2 for the 1-250 MHz range.
We have also had reported wireless HDTV boxes, and FOSCAM and AMCREST security camera systems causing RFI to garage door remote openers. Use our Garage Door Opener RFI kit to suppress the interference to the opener (VICTIM) – you need one kit for each opener. Maximize the distance from the camera to the openers may also help. Additionally shield cable to the garage door sensors may be needed depending on severity of the camera RFI.
Obvious Tech Note: make sure your remote batteries have enough energy to activate the GDO or the signal they transmit may not be large enough to over ride the RFI signal, but a fresh battery may be able to overcome the weak RFI source and allow the GDO to operate correctly.