Big HF amplifiers need a lot of current to operate effectively and as the vast majority are mobile units which run off a 12VDC supply this means using a high current power supply to get them working at home. For a linear amplifier with a high output above 100 Watts running it off its own separate power supply will give your whole radio setup good performance and stability.
So just how much juice are you going to need to power a typical amplifier?
A 500 Watt all mode linear amplifier (AM/FM/SSB) will consume about 30 AMPS at 12VDC while being used on FM but this will rise when using SSB because of the overall peak signal output from the amplifier. Take into account any surge current that a large linear sometimes needs and your looking at least a 35 AMP (constant current) 40 AMP (surge current) power source to enjoy top performance from your 500 Watt linear amplifier.
When using a 500 Watt linear in SSB mode start looking at close to 50 amps as a good current figure for a 12VDC power supply. Examining the full specs on any linear amplifier will give the current needed at full power output and use this information to help choose a suitable power supply.
Heavy Duty 12VDC Power Supplies
Pyramid PS46KX 35 AMP Power Supply
Supplying a constant 35 AMP current output with a 40 AMP surge the PS46KX is an ideal power supply for using with linear amplifiers with built in safety features that protect your equipment and the power supply itself from any fault conditions.
- Short Circuit Protection will instantly turn off the output if a complete short is detected
- Thermal Protection to shut down the power supply if it gets too hot and stopping any permanent damage
- Electronic Overload Protection with auto reset
An adjustable 12-15VDC output allows for fine tuning of the voltage to optimize performance while the user controlled built-in cooling fan will help you keep things cool during those long radio sessions.
QJE Regulated 48 AMP Compact Power Supply
As you approach the 50 AMP range of current output power supplies can be physically big taking up a lot of space in the radio shack. QJE have bucked this trend by producing a compact unit that will give a constant 48 AMP (52 AMP surge) output from a small and quiet power supply.
With an adjustable output for fine tuning voltage to suit various pieces of equipment or a fixed standard 13.8VDC voltage output for powering all that mobile radio equipment. Due to the small size of the case the output terminals are located on the rear freeing up the front panel for the combined voltage/current meter and all the control options.
Choosing the right power supply for your linear amplifier will ultimately make all the difference to how it performs.
Controlling The Cost Of Big Output RF Linear Amplifiers
Not only is a quality RF linear going to dig deep into you piggy bank but its also all the other things needed to incorporated it into your CB radio setup. Keeping these costs down to a minimum means taking a look at the existing installation, making a list of the upgrades needed and doing some shopping around.
Along with the obvious need for a power supply to feed the linear there’s also possible upgrades to antenna, coax and any diagnostics tools (SWR meters etc) that are designed to handle the extra wattage.