After extensive user feedback and testing, the consensus is clear: the H4M addresses virtually every pain point of the H2. Real users report "H4M is much much better" with improvements spanning power management, design, and expandability.
- True Power Switch: H4M features a sliding power switch that completely disconnects the battery, eliminating the phantom drain that plagued H2 users.
- No More Accidental Power-On: H2's encoder knob power control frequently activated in bags; H4M's dedicated switch prevents this entirely.
- Battery Status Display: H4M shows real-time battery percentage, voltage, current draw, and estimated remaining time directly in firmware—impossible on H2.
- Faster Charging: USB-C implementation provides significantly improved charging speeds compared to H2's micro-USB.
- Flat, Low-Profile Design: H4M's streamlined form factor makes it easier to store and transport compared to H2's bulkier design.
- Matte Screen Upgrade: The new matte display reduces glare and provides better outdoor visibility than H2's glossy screen.
- Improved Navigation Wheel: H4M returns to the combined encoder and 4-way button design for more intuitive, faster navigation.
- Modern Connectivity: USB-C replaces micro-USB for charging, data transfer, and PC connectivity.
- Built-in Speaker and Microphone: H4M includes onboard audio hardware missing from H2, enabling voice communication apps.
- Automatic Audio Switching: H4M automatically switches between internal speaker and headphones when plugged/unplugged—a feature H2 lacks.
- Microphone Toggle Switch: Physical switch allows instant selection between internal microphone and headset microphone.
- GPIO Port Addition: H4M's I2C-capable GPIO connector opens possibilities for custom modules, GPS units, sensors, and other accessories.
- Module Development Potential: Early applications like fox hunting with GPS/compass integration demonstrate the GPIO's power.
- Enhanced Firmware Support: H4M was designed in cooperation with the Mayhem development team for optimal compatibility.
| Feature |
PortaPack H2 |
PortaPack H4M |
| Power Control |
Soft power via encoder knob (accidental activation) |
True sliding power switch with battery disconnect |
| Battery Management |
4 LED indicators only, phantom drain |
Firmware-based percentage, voltage, current monitoring |
| Charging Port |
Micro-USB (slow charging) |
USB-C (fast charging) |
| Display |
Glossy screen with glare issues |
Matte screen with better visibility |
| Audio |
External headphones/speaker only |
Built-in speaker, microphone, auto-switching |
| Expandability |
No expansion ports |
I2C-capable GPIO port for modules |
| Form Factor |
Bulkier aluminum case design |
Flat, low-profile transparent case |
- Power Management: "Proper on/off button. Much better charging speed and battery info in the firmware."
- Design Preference: "Flat design!" and "Screen is better (less mirroring)" are frequently cited improvements.
- Practical Benefits: Users report the H4M feels "like a huge leap" and fixes "biggest issues with previous designs."
- Both H2 and H4M run the latest Mayhem firmware versions (2.0.1+ as of 2025).
- H4M receives priority development focus for new features and optimizations.
- All existing H2 apps and functions work identically on H4M.
- H4M benefits from web-based firmware updates via hackrf.app.
- H4M bundles typically cost $50–100 more than comparable H2 setups.
- The upgrade cost is justified by eliminating phantom drain, improving usability, and adding expansion capabilities.
- H4M represents better long-term value due to GPIO ecosystem potential and active development support.
- Upgrade if you: Experience phantom drain issues, want better portability, need GPIO expansion, or value improved user experience.
- H2 remains viable if: You've solved power issues with external modifications and don't need new features.
- New buyers: Choose H4M without question—it's the current-generation platform with active development focus.
The H4M's GPIO port positions it for an expanding ecosystem of add-on modules, similar to Flipper Zero's success. Early development includes GPS modules for direction finding, sensor interfaces, and custom protocol processors.
Experience the definitive PortaPack with professional power management, modern connectivity, and expansion capabilities that make it a true portable SDR laboratory.
Get your H4M today!