Inside a Mobile Ham Shack

What happens when a seasoned ham takes a retired ambulance and transforms it into a rolling emergency comms station? You get a mobile ham shack packed with radios, SDRs, Victron gear, and enough battery power to run off-grid during Field Day and real emergencies. Here's the tour of one operator’s ultimate off-grid command center, and what you can learn from it.

The Ambulance That Became a Ham Shack

Meet Lee Ott, callsign WA4CNL, the ARES Emergency Coordinator for Calhoun County, South Carolina. When a 1993 Calhoun County ambulance became available, the sheriff's office handed it over to Lee Ott, who transformed it into a fully functional mobile communications unit.

Originally outfitted for shoreline power, Lee upgraded it to handle a full 30-amp feed and added a generator input. But the real magic? The entire system can now run on battery power alone, including a mini-split air conditioner.

"It just works. Everything, from radios to AC, runs on battery. And I love it."

Radio Capabilities: From VHF to HF

This mobile shack is loaded with RF gear designed for real-world emergency ops:

• Winlink VHF Gateway: Transmit and receive Winlink messages, bridging local RF to global internet.
• Palmetto 800 SDR Monitoring: Listen in on the statewide emergency services network.
• Dual-band 2m/70cm Setup: Standard ham VHF/UHF rig with SDR panadapter capability.
• HF Station: Icom IC-7300 for voice and digital modes like FT8 and Winlink.
• Computer Integration: All systems HF, VHF, SDRs controlled from a single PC workstation.

For antenna deployment, a pneumatic mast extends up to 55 feet, supporting a 2-meter antenna and an end-fed half-wave antenna for HF operations.

Off-Grid Power System: All Battery, No Problem

Powering this beast is a Victron-based system built for resilience:

On a typical day, Lee reports idle draw as low as 46 watts, with everything including the AC fan running. Thanks to the Victron monitoring system, he can see live current draw and energy flows, ensuring efficient usage during off-grid operation.

Field Day Ready: Testing in Real Conditions

This system isn’t just theory, it’s being field tested. Lee plans to deploy the shack for Field Day, operating digital modes like FT8 right from the converted ambulance. His setup includes:

• Full internet access via MikroTik router connected to external Wi-Fi antennas
• POE (Power Over Ethernet) conversion for streamlined networking
• Backup connection options including cell phone tethering or county cradlepoint network
• Space to sleep and operate from inside the vehicle

The mobile shack doubles as both shelter and station, proof that you can stay operational and comfortable even in grid-down scenarios.

Lessons for Your Own Mobile Shack Build

Whether you’re a weekend warrior or a county EC, Lee’s build offers key takeaways for any ham planning a mobile shack:

Conclusion: A Blueprint for Mobile Emergency Communications

Lee’s mobile ham shack shows what's possible with planning, quality gear, and a little ingenuity. It’s more than a cool conversion, it's a real-world solution to the challenges of emergency communications in rural areas where infrastructure may be fragile.

If you’re building your own mobile station, think like Lee. Prioritize power independence, radio versatility, and system integration. Field-test it. Live in it for a weekend. Sleep in the operator’s seat if you have to. When the lights go out, you’ll be ready.