Crossband (3-band) echo repeater(non-profit project)
The device allows you to combine three amateur bands. The repeater is connected to almost any type of transceiver and is designed to issue information messages on amateur radio frequencies, for example, on how to open the repeater, as well as record voice messages with subsequent playback. Extreme simplicity provided excellent reliability of the device. Despite the simplicity of the circuit, the repeater has remarkable parameters that more expensive and hyped devices do not have. The repeater memory allows you to store a total of 3min (DD1 M25P16) to 25min (DD1 M25P128) of audio messages. One of the tasks in the development was the use of mass non-specialized and cheap SPI memory.
This project is a development of a single-channel echo repeater.
Repeater circuit diagram
The repeater can be connected to the transceiver in 2 different ways: using a squelch signal (SQL signal) and without using a squelch signal.
Open enclosure echo repeater
The device should be placed in a metal case. The components of the high-pass filters and also the processor part of the repeater should be carefully shielded. Otherwise, flash memory may be degraded by RF radiation.
Echo repeater inside
Software written specifically for the echo repeater allows you to fully configure the device in a few minutes. However, if desired, the device can be “fine-tuned” using the console utility. The memory card and details of the programming process are in the device description, which can be downloaded here here.
Main dialog box
The software installation package, documentation and firmware can be downloaded here.