Getting Started

This guide will help you get your RS-UV3A up and running for basic voice operation.

What You’ll Need

Before powering on your RS-UV3A, gather these essentials:

1. Antenna or 50Ω dummy load
2. Power source (one of the following):
   • USB cable and USB power supply/computer
   • 9V battery
   • 12V DC wall adapter (5.5×2.1mm barrel connector)
3. Speaker (or headphones)
4. Microphone (electret type)
5. PTT switch (momentary contact)

Minimum Connections

1. Antenna

Connect a suitable antenna or 50Ω load to the SMA jack. The RS-UV3A is tolerant of antenna mismatches (even open or short circuits), but a well-matched antenna gives best performance and equipment longevity.

Never transmit without a load

While the RS-UV3A can survive momentary antenna mismatches, always connect an antenna or dummy load before transmitting.

2. Power

You have several options for powering the RS-UV3A:

Method	Voltage	Notes
USB	5V	Powers board and provides serial
VIN Jack	3.5–16V	5.5×2.1mm barrel, center positive
PW Header	3.5–16V	For custom installations

The RS-UV3A includes diode protection, so USB and external power can be connected simultaneously. This provides backup power capability—connect a USB power bank to keep operating if primary power fails.

Power Switch

The PW header has a factory-installed jumper. Remove it and wire in a switch for on/off control.

3. Audio and PTT

For basic voice operation, connect:

Connection	Signal	Notes
SPKR	Speaker output	8Ω speaker, level via VR1
MIC	Microphone input	3.3V bias for electret mic
PTT	Push-to-talk	Ground to transmit

The ground pads next to each signal provide convenient connection points.

Factory Default Settings

Out of the box, your RS-UV3A is configured for:

• Frequency: 146.520 MHz (2m FM simplex calling frequency)
• Mode: Simplex (TX and RX on same frequency)
• Power: High (~200 mW)
• Squelch: Level 3
• Baud Rate: 19200

At this point, you can listen on 146.52 MHz and transmit by pressing PTT!

Next Steps

To change frequencies or adjust other parameters, you’ll need a serial connection:

• Serial Setup — Connect to a computer for full control
• Connections Reference — Detailed pinouts for all connectors
• Voice Operation — In-depth guide for voice communications

Quick Test

1. Power on the RS-UV3A
2. Connect a speaker to hear receiver audio
3. Turn the squelch control (VR1) to hear background noise
4. Tune a handheld radio to 146.52 MHz and transmit
5. You should hear the signal on your RS-UV3A speaker

If you have a serial terminal connected:

FS146520    # Confirm frequency
SQ3         # Set squelch level
VU15        # Set volume