PTT over Ethernet

  • Hallo,

    for those who like to control their amplifiers idle current, my idea is to send a PTT-Signal via Ethernet to the Radio which can be placed far away (Pluto and amplifier) closed to the dish. To avoid confusion, the PTT-Signal is switching the amplifier to transmit. For this special solution the Pluto is not involved.
    PoE-Adapters gives Ethernet and two independend lines for a very low price. The PoE-Plugs can be removed or changed (in my shack to Cinch).

    The PTT-Signal at the PC-Side is generated with a USB-Relay. The Relay is supported by the Console if it is conform with HID-Standard.

    I just tested the adapters, works nice. It is possible to use a PTT-Signal from GPIO-Ports of the Pluto also but there is a delay of about 800 ms switching on and off.

    Have fun with fluently SSB-Speaking.

    Andreas DL5CN

  • Hallo Valdimir,

    ok, but a diagram isn't necessary. The POE-Adapters (can be seen above) with a RJ45-Socket are sticked to each end of a normal cable. And the RJ45-Plugs of the adapters are connected to Ethernet devices. This gives a normal Ethernet-Connection (red) with 2 twisted pairs, for example between Adalm Pluto and PC . The other two wire pairs can be used to bring the PTT-Information (green) from the USB-Relay at the PC to the Pluto. With other words, the POE-Adapter splits the Ethernet cable into two functions, normal Data exchange and PTT-Signal.

    Oh, I remeber a symbolic graphic, I did for a friend some time ago. Here it is.

    To switch to transmit, the PTT-Button gives a "low" to a USB to TTL-Converter and the Console goes in transmit mode.

    If there are more questions, don't hesitate to ask.


  • Hallo Vladimir,

    1. WSJT unterstützt einen seriellen COM-Port für PTT. Ist dieser an aktuellen PCs nicht mehr vorhanden, kann man einen USB zu seriellen Wandler nehmen, z.B. einen FTDI-Chip wie FT232. Das erfordert einen FTDI-Treiber im PC. An einer der Statusleitungen (CTS, RTS) kann man ein Signal abnehmen. Dem Programm muss die COM-Port-Nummer mitgeteilt und die Statusleitung ausgewählt werden.

    2. Um einen Pluto mit Ethernet zu betreiben ist ein USB zu Ethernet-Wandler erforderlich. Der Micro-USB-Stecker muss einen OTG-Kontakt haben. Damit wird der Pluto auf Ethernet geschaltet. Es gibt viele USB zu Ethernet-Wandler, nicht alle funktionieren, leider. Da sind Tests erforderlich. Zusätzlich müssen am Pluto und PC Einstellungen der IP-Adressen erfolgen oder DHCP benutzt werden.