DRA-818 VHF Mini Transceiver Module

Advancement in chip technology and DSP allowed so we can have a complete 1W VHF transceiver in a small module.

The absence of special crystal and mechanical filters, discriminator coils etc, allowed for reducing costs too.

The DRA-818V module is one example, made in China, costs under USD 15.00, take a look at its specs:

Frequency Range: 134~174MHz
Tx/Rx frequency independent, can be the same or at any difference
Channel spacing: 12.5 or 25KHz
Configurable multi-channels
Receiver Sensitivity: -122 dBm
Output power: +27/30dBm (high/low as selected)
CTCSS / CDCSS codes built-in
8 volume levels controlled from the UART interface
8 squelch levels controlled from the UART interface
Simple 9600N81 UART interface to control
Operating Temperature: -20°C ~+70°C

TX current: 450/750mA
Supply voltage: 3.3~4.5V (5V absolute maximum).