As an enthusiast of radio communication, I recognize the importance of having a coax switch, which gives me the freedom to switch between different antennas or transceivers by using just a single coaxial cable. This is a perfect solution for anyone like me, an amateur radio operator, a hobbyist, or even a professional who values the flexibility and convenience in radio setups.
Let me share with you how a coax switch works. The magic lies in its mechanical or electronic relays that are designed to connect or disconnect the center conductor and the shield of the coaxial cable to varying terminals. These terminals are marked with numbers or letters and the switch position indicates which terminal is connected to the common port, which is the port connecting to either the antenna or the transceiver, depending on the direction of the signal.
I love that coax switches come in different shapes and sizes, boasting diverse specifications and features that cater to my specific needs. Here are some of the things I often look for:
Frequency range: The switch must handle the highs and lows of frequencies without losing or distorting the signal.
Power rating: I prefer switches that can handle high power levels without getting damaged or overheated.
Insertion loss: Less insertion loss ensures better signal quality and efficiency.
Isolation: A switch with a high isolation level guarantees better signal integrity and noise reduction.
VSWR: The voltage standing wave ratio measures how well the impedance of the switch matches the impedance of the cable and equipment. A lower VSWR means better impedance matching and less reflection.
Connector type: I make sure the connector type matches the type of cable and equipment used.
Grounding: I love features that allow unused terminals to be automatically grounded for static and RF protection, preventing potential damage.
Switching mechanism: I have options between manual, remote, or automatic switching mechanisms.
Two of my favorite models are the MFJ-1702C and MFJ-2703 coax switches from MFJ Enterprises Inc., a leading manufacturer in the industry. Both these switches are very well built and very heavy to provide a solid base when turning the indicator for switching.
MFJ-1702C is a 2-position coax switch that comes with a center ground position and lightning surge protection. It can handle frequencies from DC to 900 MHz, power up to 2.5 kW PEP/1 kW CW at HF, insertion loss less than 0.2 dB, isolation more than 60 dB at 300 MHz, and more than 50 dB at 450 MHz. It has a sturdy die-cast design and is just the right size for my needs.
The MFJ-1702C is great for switching between two antennas or two transceivers at HF or VHF/UHF frequencies. Its built-in lightning surge protector is a lifesaver in case of a strike. To use it, I just connect a coaxial cable to the common port labeled C on the switch and connect it to my antenna or transceiver. Another coaxial cable is then connected to one of the terminals labeled 1 or 2 on the switch and the other end to my other antenna or transceiver. Then, I just rotate the knob on top of the switch to select which terminal I want to connect to the common port.
On the other hand, the MFJ-2703 is a 3-position coax switch with gold plated flanges and connector contacts that provide low VSWR and low insertion loss. It can handle frequencies from DC to 800 MHz, power up to 2 kW at HF, insertion loss less than 0.2 dB, isolation more than 70 dB, and has UHF (SO-239) connectors. Its use is similar to the MFJ-1702C, just with an extra terminal to utilize.
In conclusion, coax switches are essential gadgets that offer an easier way to switch between different antennas or transceivers using a single coaxial cable. They boast different specifications and features that cater to varying needs, making them perfect for different applications.
The MFJ-1702C and MFJ-2703 models from MFJ Enterprises Inc. are my top picks for delivering high quality and reliability. They’re an excellent addition to the equipment list of any amateur radio operator, hobbyist, or professional.
73, Marius, de ZS1ML
