THE PROBLEM:
You Spent $4,000 on Your Radio. Are You Protecting It With a $3 Fuse?
Fuses were patented over 100 years ago. The basic concept hasn’t changed: a thin piece of wire melts and breaks when too much current flows through it. Fuses do a reasonable job of protecting wiring and preventing fires — and that’s exactly what they were designed to do.
The problem is that your radio isn’t wire. It’s sensitive electronics. And fuses have two significant weaknesses when it comes to protecting gear like yours:
They’re slow. A fuse takes time to heat up and melt. Modern electronics can be damaged in milliseconds — faster than any fuse can respond.
They only protect against overcurrent — not overvoltage. If your power supply fails and sends 16 volts into a radio designed for 13.8V, your fuse won’t blow. Your radio will absorb every volt of it.
Many hams have had radios and other 12V electronics destroyed by overvoltage from a faulty power supply. It happens more often than you’d think — and it’s completely preventable.
THE IRONY
The $59 Power Supply Problem
There’s a running joke in the ham radio community: operators will spend $4,000 on a new radio and then head to Amazon to find the cheapest power supply they can get away with.
It’s understandable. Power supplies seem interchangeable. But cheap supplies fail — and when they fail, they often fail dangerously, sending overvoltage spikes directly into your equipment.
The SPS-1 Smart Power Switch sits between your power supply and your radio. Whatever comes out of that power supply, the SPS-1 decides whether it’s safe to pass through.
THE SOLUTION
Introducing the SPS-1 Smart Power Switch
The SPS-1 replaces your traditional fuse holder with a solid-state protection device that monitors your power 1,000 times per second. It uses an automotive-grade Infineon PROFET™ semiconductor switch — the same technology trusted in cars and trucks — combined with a microcontroller that enforces three layers of protection:
Overvoltage Shutoff If voltage exceeds a safe threshold, the SPS-1 disconnects your equipment in under 1 millisecond — far faster than any fuse could react. No damage. No drama.
Configurable Smart Fuse Set standard current limits from 5 to 25 amps using the rotary dial, or set it anywhere from 5 to 35 amps over the DCN interface. If current exceeds your setting, the SPS-1 shuts off. No fuses to carry. No fuses to replace. No burned fingers. Reset can be configured to be manual or automatic.
Undervoltage Monitoring When voltage drops below a safe level — like when your battery is dying or your supply is struggling — the SPS-1 disconnects before your equipment starts behaving erratically.
Local or Remote Control You can control the switch locally with a simple, low-current switch closure to ground. Status and Fault outputs are provided for LED indicators. You can also control it remotely over the DCN interface- see below.
Automatic Mobile Mode Running ham radio in your vehicle? The SPS-1 detects when your engine shuts off (voltage drops as charging stops) and powers down your radio automatically. When you restart, it brings your radio back up. No ignition tap required. No wiring modifications needed. An adjustable turn-off delay keeps your radio on for 1 to 100 minutes to finish up that last QSO.
DCN COMPATIBILITY
Built for Integrated Station Control
If you’re running a Sierra Radio Systems Station Controller or building a network using the Device Control Network (DCN) protocol, the SPS-1 is a native fit.
The DCN, developed by George KJ6VU of Sierra Radio Systems, is an open, published communications protocol used to connect station control hardware over RS-485 wiring via standard CAT5 cable. It’s the backbone of an increasingly popular ecosystem for integrated ham station control — from remote HF stations to repeater sites to full shack automation.
The SPS-1 uses the same RJ-45 connector and pinout as Sierra Radio Systems Station Controller modules and fully implements the DCN command protocol. That means it can sit on the same network as your other DCN hardware — GPIO modules, coax switches, RF watt meters — and be controlled and monitored from the same interface.
What you can do over DCN:
- Remote on/off control — switch your station power remotely from your Node-Red dashboard, a Python script, or any DCN-compatible interface
- Live monitoring — query real-time voltage, current draw, and device status over the network
- Remote configuration — set or change any SPS-1 parameter (current limit, overvoltage threshold, Mobile Mode settings) without physical access to the unit
This makes the SPS-1 particularly well suited for remote station installations, where knowing the power state and being able to cycle it remotely can save an unnecessary site visit.
The full DCN command reference for the SPS-1 is documented in the SPS-1 User Manual, available on the store page and on GitHub.
Check out Sierra Radio Systems and Station Controller equipment here:
DCN protocol and Sierra Radio Systems Station Controller are the work of George KJ6VU / Sierra Radio Systems. Used with permission.
SEE IT IN ACTION
Watch the Product Introduction Video
PRE-ORDER
Pre-Order the SPS-1 — Limited First Run
The SPS-1 is currently available for pre-order. I’m a one-person operation running a first production run of 100 units, and I’m funding it through pre-orders to keep costs manageable and avoid building inventory I don’t need.
Pre-order price: $99.95 (introductory pricing for the first production run) Pre-order deadline: July 31, 2026
A $10 deposit secures your unit. The balance is due when your order ships.