← Back to hardware

USB Relay / Solid-State Relay Module

A USB-controlled relay or solid-state relay (SSR) module provides a fully isolated dry-contact PTT, or switches higher-current loads (radio power, fan, amplifier keying) under ORLP control. Why it matters: Some commercial radios and repeaters want an isolated contact closure for PTT rather than an open-collector pull-to-ground; an SSR delivers that cleanly. Relays also let a node power-cycle a radio or accessory remotely. Caveat: Mechanical relays add a few milliseconds of switching latency and wear over millions of keyings — for high-traffic PTT, prefer an SSR or an opto keyer. Use mechanical relays for slower control duties (power, fan).