Any radio can be a base station radio. What really makes a radio a base station radio, is how you set it up, and use it. However, in general, when people talk about base station radios, they mean larger stationary radios that have more power and capabilities than handheld or mobile radios. Some characteristics of a base station radio are that it is not meant to be moved, it has a permanent place in your house or shack, it usually has a larger more permanent antenna mounted as high up as possible, and an external power supply if the radio does not have an internal power supply, usually a 120V to 12V power supply.
The Radio
In the modern era of radios, a lot of the “base station” rigs are actually quote mobile, or easily used mobile if needed. Radios have gotten smaller, and they are able to pack in a lot more features than in the “good old days”. Most base station radios will be capable of 50 – 100W of output to help your signal get out. The will generally be larger, and have more buttons, bigger dials, and bigger and better screens. Because they are not as limited on space as when they make a handheld, or a mobile radio, they give you more buttons to make settings and changes easier and faster. Same for the dial and the screen. When they have more real estate, they give you better features to make life easier. Since the radios can be larger, they also have more room for additional circuitry. Smaller handheld or mobile units generally don’t hold a candle to the filtering, sensitivity, or sound quality of the much larger and more expensive base stations.
The Antenna
Base station antennas are generally permanently mounted, and larger with more gain than handheld or mobile antennas. Since the antennas aren’t as limited on space, they can be larger or longer, and thus have a lot more potential to be high gain. Also, on a base station antenna, since you are usually able to mount them much higher than you would be able to get a handheld or mobile antenna, you will have a longer line of sight if it is a vertical antenna like an omnidirectional antenna for VHF/UHF. Most larger base station radios however are geared more toward HF frequencies, where line of sight isn’t as important since you are skipping your signal off the ionosphere. Also, when you are dealing with HF, you are usually using something much larger than a pole mounted unidirectional antenna. EFHW (End Fed Half Wave), Dipoles, Hex Beams, Moxon, Loops, and large directional Yagis called Beams are all common. Wire antennas, like the EFHW don’t really require a pole or tower. You can have one end start from your radio, and the other end going up into a tall tree. For Dipoles, you can have them in lots of configurations although the inverted V and flat are the most popular.
Coax
Again, since you are not moving the radio around, or limited on space, base station radios usually take advantage of much larger coax that has much less loss per foot. 1/2″ coax is a standard, but you can get away with much less, or go for broke (literally) and install Heliax. You will need to consider the characteristics on the loss for the frequencies you plan to use the most. If you are using VHF/UHF the most, you will want a coax that has less loss in the 144 – 450 MHz range. For HF, you would want a coax with great efficiency in the 3 – 54 MHz range. In general, the larger the coax line’s diameter, the less loss you will experience. Some great coaxes to consider are Messi and Paoloni Airborne or Ultraflex in 10mm or 13mm, LMR400, RG8, RG8X, and many more. You will need to decide which coax meets your requirements, and will work in your situation (bend radius etc.).
Grounding
Every radio needs a good ground. Having a common ground for all of your equipment is important to avoid problems. A good ground helps establish an RF ground. It helps reduce electrical noise and interference. Grounding refers to the path you give to a ground potential for any fault currents to go to ground instead of your or your equipment. This can help protect you from static buildup, electrical shocks, and lightning strikes. We also need to discuss the difference between bonding, and grounding. Bonding all of your equipment together means all of your equipment has a common connection from the metal part of the chassis to every other piece of equipment so that they are all connected by a ground wire of some sort. Once bonded, you would then connect the bonded ground to a path to ground, like a ground wire going to a grounding rod, usually 8 feet long and driven into the ground. Some installations use multiple ground rods, all tied to one another so you don’t have a difference in ground potential. Generally, when it comes to ground wires, the thicker and more conductive the better. So copper will usually be better than aluminum due to its better conductivity if the 2 wires are the same gauge, but a thicker aluminum might be better than a smaller copper wire for the price.
Surge Arrestors
Once you have bonded your equipment, and have established a good path to ground, you will want to ensure your equipment is protected from surges with a surge protection system. Don’t get me wrong, it you sustain a direct lightning strike, no surge arrestor will protect everything. However, there are a lot of times when a lot of static in the air, or a nearby strike will induce a surge or a charge in the air that is seeking all possible paths to ground. Give it a safe one.
Most surge arrestors have a replaceable gas discharge tube (GDT). These gas discharge tubes work by allowing the voltage to go across a gas-filled tube, causing the gas to ionize and form a plasma, which then conducts electricity and produces light, heat, or a protective crowbar effect, thus protecting your equipment from becoming the fastest path to ground. The GDT is between the center conductor and the shielding on your coax. Normally, there is no connection between the two, but once it ionizes, you will need to replace it. This would be apparent if you see your VSWR (Voltage Standing Wave Ratio) increasing over time, or suddenly after a storm or event.
Power Supply
A lot of base station radios do not have a built-in power supply. A power supply will have a rating, usually expressed in Amps, which tells you how many amps it can provide. The more amps it is capable of sustaining, the more it will cost. So if your radio only needs a 23 Amp power supply, buying one that can put out 45 Amps will just be a waste of money.
When it comes to power supplies, there are 3 main types: Linear, Switching, and Battery.
Linear Power Supplies
A linear power supply will be bigger, heavier, less efficient, and usually quite a bit more expensive than a switching power supply. A linear power supply will also generally provide a much cleaner power to your radio, which means the power supply will not introduce interference to your signal.
Switch Mode Power Supplies
Switching (or switch mode) power supplies on the other hand, are cheaper, lighter, and more efficient. Due to the way a switching power supply works however, they are more prone to introduce some noise into your radio/signal. How much noise will depend on how much filtering is in the power supply, and how well the circuit is designed. The Samlex switching power supplies I use, are well built and I have not noticed any discernable difference between them and my Astron linear power supply.
Battery Power
A stand-alone battery however is the absolute most quiet power source you can get. Pure DC, no noise. However, you will always have to find a way to recharge the battery. If the battery is in your vehicle, the vehicle will introduce some noise onto the power wires. If the battery is in your house, a battery charger will likely do the same. If you charge the battery when not in use, and disconnect the charger when it is in use however, you will have really clean power.
Accessories
Base stations lend themselves to a lot of accessories since they have a permanent place in your home or shack. Things like a really comfortable chair, a high quality microphone, external speaker, professional headset, a computer to run HamClock, tracking software, or logging software for your contacts. Some Hams have custom built desks or racks to hold their equipment. They run multiple clocks so they can easily tell the time in several time zones. They have large format maps on the wall for easy reference. They sky is the limit when it comes to making your base station easier or more fun to use for hours on end.
