Astron Power Supply Guide: Linear RS vs Switching SS

Best for
Single-radio shacks needing linear quiet

The Astron 20 Amp Power Supply is the RS-20A from the linear RS series. According to the description it delivers 16 amps continuous with a 20 amp intermittent rating at 13.8V DC, where intermittent means a 50 percent duty cycle of five minutes on and five minutes off. That profile suits a VHF/UHF mobile rig, a scanner and accessories, or a small HF rig running reduced power, because transmit current stays well inside the continuous figure.

Be careful with the spec table on this listing. It names a 1700 watt output, an ATX connector, a rack form factor and a personal computer as the compatible device, none of which matches a 20 amp, 13.8V linear radio supply. The description and features are consistent with the RS series, so treat those as the reliable part and ignore the PC-style fields. The listing does not specify dimensions or weight.

• Fold-back current limiting that protects against excessive current and a continuous shorted output
• Crowbar overvoltage protection
• Maintains regulation and low ripple at low line input voltage
• Heavy-duty heat sink with a chassis-mount fuse

Where it gives way: if your transceiver is a full 100 watt HF radio, 16 amps continuous is not enough headroom, and the RS-35A or RS-35M-AP is the better match.

Best for
100W HF rigs on a linear supply

The RS-35A Astron Original Power Supply is the model many operators mean when they say “an Astron.” The description lists 25 amps continuous and 35 amps intermittent at 13.8V DC on the same five-minutes-on, five-minutes-off duty cycle, which is the current class a typical 100 watt HF transceiver needs on SSB and short CW sessions.

Being linear, it is big: the listing gives 7 x 13 x 13 inches and an aluminum enclosure, with UL, FCC and CE listed. The spec table shows 483 watts maximum, which lines up with 35 amps at 13.8 volts. It carries the same protection set as the 20 amp model. A line about a 20+4 pin ATX connector is again a leftover from a PC template and does not describe how you actually connect a radio. The listing does not mention meters or adjustable output, so if you want either, look at the RS-35M-AP instead.

• 25A continuous, 35A intermittent at 13.8V DC
• Fold-back current limiting and crowbar overvoltage protection
• Heavy-duty heat sink with chassis-mount fuse
• UL, FCC and CE listed

Best for
Compact desk setup for mid-power radios

The SS-18 SS18 S-18 Original Astron Switching supply is the middle of the switching range. The title and description agree on 15 amps continuous and 18 amps ICS (intermittent) at 13.8V DC, with 120/220 volt input. The description calls it RFI immune and built with robust components for moderate to high power applications.

This is the model for a 50 watt mobile on the desk, a dual-band rig with accessories, or a lab bench running 12V gear, where you want a supply that takes up far less space than a linear box. It lists protection against overvoltage and overtemperature, plus fuse-based overcurrent protection, and an upper temperature rating of 50 °C. The spec block also claims 13.8 watts output and 100 watts wattage, which contradicts the 15 amp rating, so rely on the title and description for current.

• 15A continuous, 18A peak at 13.8V DC
• 120/220V input range
• Overvoltage, overtemperature and fused overcurrent protection

It gives way to the RS-35A or SS-30M-AP as soon as you move to a 100 watt HF rig.

Best for
Operators wanting meters and Anderson ports

The RS-35M-AP RS35MAP Astron Original Power Supply takes the RS-35 linear platform and adds the features a shack owner actually looks at every day: dual meters and Anderson Power ports. The description lists 25 amps continuous and 35 amps surge, 105-125V AC input and 13.8V DC output that is internally adjustable from 11 to 15V DC.

Adjustable output helps if you run gear that prefers a slightly different voltage, and the meters let you watch voltage sag and transmit current without extra hardware. It is solid-state regulated with fold-back current limiting, crowbar overvoltage protection, a heavy-duty heat sink, a three-wire AC cord and a chassis-mounted fuse. The trade-off is weight: the listing says 25 pounds, at 11 x 11 x 5 inches. One spec field says a barrel connector, which conflicts with the Anderson ports named in the title, so expect Anderson outputs and confirm the rest on arrival.

• Dual meters for voltage and current
• Anderson Power output ports
• Internally adjustable 11-15V DC output
• FCC, UL and CE listed

Best for
Handheld chargers and low-power mobiles

The Astron SS Series Switching Power Supplies listing is for the SS-12, the smallest model here. It is rated at 10 amps continuous and 12 amps ICS at 13.8V DC with 120/220 volt input, measures 1 3/8 x 6 x 9 inches and weighs 3.4 pounds, and comes with a DC power cord.

That size and current make it a good match for handheld chargers, a low-power VHF/UHF mobile, a scanner or a small accessory bench. It lists short circuit and overvoltage protection plus automatic over-temperature shutdown, and states that output current is rated for continuous service. The description notes that some SS models are designed to work with specific land mobile radios. The spec table lists a minimum input of 115 volts and a single fan. It is not the right supply for a 50 watt or larger radio; step up to the SS-18 for that.

• 10A continuous, 12A ICS
• Automatic over-temperature shutdown
• DC power cord included

Best for
Portable or go-kit stations using PowerPoles

The SS-30M-AP SS30MAP Astron Original Switching Power supply is the switching choice for a larger rig. The title promises USB and PowerPole ports and a 30 amp peak, and the spec table names mobile radios as the compatible device, with dimensions of 4 x 11 x 6 inches.

The data here is thin. The listing does not specify the continuous current, whether there are meters, or the input voltage range, and the spec block lists 30 watts output, which cannot be right for a 30 amp peak supply. The only protection feature named is short circuit and overvoltage protection. If you want a compact supply with PowerPole connections for a go-kit or portable operating box, this is the one in the lineup that fits, but check the continuous rating against your radio before buying. Anyone planning battery-backed field operation may also want to compare a portable power station for off-grid use.