Best 13.8V Power Supplies for Your Ham Radio Station
Buy a 13.8-volt supply rated for at least 25–30 A continuous if you run a 50 W mobile as a base, or 30 A+ for a 100 W HF rig. The Powerwerx SS-30DV is the best all-rounder (30 A, Powerpole outlets), the Astron RS-35M is the zero-RF-noise linear classic, and the Samlex SEC-1235M and Alinco DM-330MV are proven RF-quiet switchers. Cheap generic switching bricks can hash up HF — this is the one station component where 'unbranded bargain' backfires.
Every mobile and base transceiver expects what a car battery provides: 13.8 volts DC, with serious current on transmit. The power supply is the least glamorous purchase in radio and the one that quietly decides whether your HF receiver hears signals or a wall of switching hash.
This guide does the amps math for common rigs, explains the switching-vs-linear noise question honestly, and picks four supplies that hams have run for years. It pairs with best beginner base stations and best mobile radios under $300 — the radios these supplies feed.
Top picks for 2026
Independently chosen for beginners. We never show live prices — tap through to check the current price.
Powerwerx SS-30DV
30 A continuous, native Anderson Powerpole outlets plus binding posts, compact and quiet. The default answer for powering a 50 W mobile-as-base or a 100 W HF rig without drama.
Astron RS-35M
The 20-pound transformer supply your elmer still uses: 35 A intermittent / 25 A continuous, analog volt and amp meters, and absolutely zero switching hash on HF. Heavy is the feature.
Samlex SEC-1235M
A switching supply with a linear-like reputation on HF, front meter, and 30 A on tap in a lunchbox footprint. The middle path when an Astron is too heavy and generic bricks are too noisy.
Alinco DM-330MV
30 A switcher with variable 5–15 V output, front convenience terminals, and a noise-offset knob that shifts residual switching birdies off the frequency you're using — a clever HF-friendly touch.
How many amps do you actually need?
Size the supply from your radio's transmit current draw (in the manual's specs page), plus headroom:
| Radio class | Typical TX draw | Supply to buy |
|---|---|---|
| 25 W dual-band mobile | ~6–8 A | 15 A+ |
| 50 W dual-band mobile | ~10–13 A | 20–25 A+ |
| 100 W HF transceiver | ~20–23 A | 30 A+ |
| QRP rig (5–20 W) | 1–5 A | Almost anything clean |
The rule of thumb: buy roughly 25–30% more continuous capacity than peak draw. A supply loafing at 60% load runs cooler, quieter (fan-wise), and lasts. Note the difference between "peak/intermittent" and "continuous" ratings in listings — the Astron RS-35M, for example, is 35 A intermittent but 25 A continuous, which is exactly right for a 100 W rig.
Switching vs linear: the RF noise question, honestly
Two technologies, one trade-off:
- Linear supplies (big transformer, heavy): electrically silent — effectively zero RF hash — but heavy, warm, and pricier per amp. This is why 20-pound Astrons from the 1990s still sell.
- Switching supplies (light, efficient): modern ham-brand switchers (Powerwerx, Samlex, Alinco) are engineered to keep switching noise out of the HF bands and are fine for 99% of stations. Generic switching bricks — CB-shop specials, repurposed server supplies, no-name Amazon boxes — are the ones that paint S7 hash across 40 meters.
Practical guidance: for a VHF/UHF-only station, any reputable switcher is fine (noise issues concentrate on HF). For HF, buy a ham-brand switcher with a noise-offset feature or a linear. If you can hear a buzz-saw across the band that disappears when the supply is on battery, you've met bad switching hash.
Standardize on Anderson Powerpoles early
The ham world (and ARES officially) standardized DC connections on Anderson Powerpole connectors: genderless, polarized, rated for real current, and identical on every club member's gear. Adopt them on day one — put Powerpoles on the radio's DC leads and buy a supply with Powerpole outlets (the Powerwerx SS-30DV has them native), and every battery, solar panel, and friend's shack becomes plug-compatible with your station. A crimper and a bag of 15/30/45 A contacts cost about $40 once, and end the era of bare-wire-under-thumbscrew connections.
Setup details that prevent smoke
- Fuse both leads at the radio (mobile radios ship with fused harnesses — keep them inline even on a bench supply).
- Use real wire gauge: 10 AWG for 100 W rigs' full runs; thin speaker wire drops voltage on transmit and causes mysterious resets.
- Check the meter under load: 13.8 V idle sagging below ~12 V on transmit means undersized supply or wiring.
- Keep the supply out of the RF path: a couple of feet from the antenna feedline and a common ground point — see grounding & lightning protection.
- Adjustable-voltage models: set 13.8 V and leave it; the adjustability is for edge cases, not experimentation with your $1,000 rig attached.
Battery backup: the other half of the power plan
A supply runs the station while the grid is up; a 12 V LiFePO4 battery keeps it alive when the grid isn't. The clean pattern: supply charges the battery through a West-Mountain-style power gateway (or you simply move Powerpole plugs), radio runs from the battery bus. A 20 Ah LiFePO4 runs a 50 W mobile for an evening of normal use, or an HT essentially forever. If emergency capability is a goal, this is the architecture — more in emergency communications 101.