Hardware Revisions

The RS-UV3 has gone through several hardware revisions. This page documents the differences between revisions and compatibility considerations.

Revision Summary

Revision	Key Features
Rev A (Current)	On-board USB, buck-boost DC-DC, 3.5V–16V input
Rev D	Battery charging, 9V–16V input, FTDI cable required
Rev C	Battery charging, LED indicators, sub-RX header
Rev B	Basic design, battery charging

RS-UV3A Rev A (Current)

The Rev A is the latest and recommended version.

New Features in Rev A

Feature	Description
On-board USB	FTDI FT230X for driverless USB serial
Wide-range DC-DC	Buck-boost converter accepts 3.5V–16V
USB Power	Can be powered entirely from USB
Micro USB	Single connector for power + serial
LED Indicators	Power, TX, and user-configurable Status
DE-9 Power	Optional 8.5V on pin 6 via I/O_P jumper

Removed in Rev A

Feature	Notes
Battery Charging	No MCP73213 charger circuit
Battery Connector	No BATT header
9V minimum	Now accepts down to 3.5V

Specifications

Parameter	Rev A
Input Voltage	3.5V – 16V
Power Consumption	1.6W max
Weight	34 grams
USB Serial	On-board FTDI

RS-UV3 Rev D

Features

• Battery charge management (MCP73213)
• 8.4V dual-cell LiPo support
• 9V–16V DC input required
• Three LEDs (PWR, TX, ST)
• Requires external FTDI cable for serial

Specifications

Parameter	Rev D
Input Voltage	9V – 16V
Battery	8.4V dual-cell LiPo
Charge Current	150 mA
Weight	~40 grams
USB Serial	External FTDI cable

RS-UV3 Rev C

Features

• First revision with LED indicators
• Sub-receiver RF output header (S_RX)
• Battery charging
• I/O power jumper added

Specifications

Parameter	Rev C
Input Voltage	9V – 16V
RX Current	180 mA max
TX Current	400 mA max
Weight	40 grams

RS-UV3 Rev B

The original production version with basic features.

Features

• Basic transceiver functionality
• Battery charging
• No LEDs
• No S_RX header

Rev B Support

If connecting RS-UVPA to Rev B, contact HobbyPCB Technical Support for guidance.

Firmware Compatibility

All revisions use the same firmware, but some features are revision-specific:

Feature	Rev A	Rev D	Rev C	Rev B
LD (ST LED)	✓	✓	✓	—
BS (Battery Status)	Legacy	✓	✓	✓
VT (Voltage)	✓*	✓	✓	✓

*Rev A returns internal 8.5V rail voltage

Physical Compatibility

All revisions share the same:

• Board dimensions (120 × 75 mm)
• Mounting hole positions
• SMA antenna position
• Arduino header pinout

This ensures enclosures and accessories are compatible across revisions.

Upgrading from Older Revisions

Rev C/D to Rev A

If upgrading from Rev C/D:

1. Battery: Rev A has no charging—use external power management
2. Serial: Rev A has on-board USB—FTDI cable not required
3. Voltage: Rev A accepts lower voltages (3.5V vs 9V)
4. Settings: Use FD1 to reset to defaults after firmware update

Power Considerations

Revision	Minimum Voltage	USB Power
Rev A	3.5V	Yes
Rev C/D	9V	No (FTDI for serial only)

RS-UVPA Compatibility

The RS-UVPA power amplifier is compatible with:

• RS-UV3A Rev A
• RS-UV3 Rev D
• RS-UV3 Rev C

Rev B may require additional modifications—contact HobbyPCB.

Installation Differences

Rev A Installation:

1. Remove solder from SJ1
2. Add AMP, PW, and PA headers
3. Remove VIN connector (interferes with amp)
4. Mate boards

Rev C/D Installation:

1. Remove solder from SJ1
2. Add required headers
3. Remove VIN connector
4. Mate boards

Identifying Your Revision

Check the silkscreen on the PCB near the edge for the revision letter:

• “RS-UV3A Rev A”
• “RS-UV3 Rev D”
• “RS-UV3 Rev C”

Or query firmware:

FW

Firmware versions don’t indicate hardware revision, but feature behavior may hint at the hardware (e.g., BS command behavior).

Documentation Notes

This documentation primarily covers the RS-UV3A Rev A. Some features described may not be available on older revisions:

• On-board USB: Rev A only
• USB power: Rev A only
• Battery charging: Rev C/D only
• 3.5V minimum: Rev A only

When in doubt, refer to the original documentation for your specific revision on the HobbyPCB Wiki.