Operating Notes

Laptop: Special Mouse Controls:

  • Roller: When using a laptop that has a mouse with a roller, the roller can be used to change vfo settings by hovering on the frequency digit to change and rolling the roller. The roller can also be used to adjust slider values by hovering over them and rolling up or down.
  • Right Mouse Button Click as PTT: If the mouse pointer is anywhere in the radio control area, pressing and holding the right-mouse-button down will put the radio into Tx state. Releasing will switch the radio back to Rx.
    Also see USB Mic Ptt Adapter.

Laptop Tx/Rx with space bar:

After initially clicking the Tx/Rx button in the radio control interface, subsequent Tx/Rx toggling can be done with the space bar as long as it stays selected in focus.


RemoteTx works well with a variety of headsets and mics. Excellent audio reports have even been achieved with an iPhone and it’s stock earphone/mic ear buds. What works well with your phone, tablet or computer will work fine with RemoteTx. It is best to experiment with gain levels on the device and the radio while you are at your station, note the best settings, and then leave it that way when you operate remotely.

Things that have been tried with success:

  • iPhone with stock earphone/mic.
  • Yamaha CM500 on Dell laptop.
  • Sony MDR 100ABN noise cancelling bluetooth headset on iPhone and iPad.
  • Heil HMM-IC on Dell laptop with USB Mic Ptt adapter. (See Photos)
  • Kenwood Dynamic Mic (from TS-480) with USB Mic Ptt adapter. (See Photos)

Audio Timing:

Depending on the latency of the network you are on, there can be a slight delay in audio transmission. The most common effect this has on operators is the tendency to switch from Tx back to Rx a little early leading to the audio at the end of the transmission being clipped. (Tx/Rx switching activates faster than the audio streaming.) Simply keep this in mind and hesitate a fraction of a second after you have stopped talking to switch back to Rx.

Network Quality:

The RemoteTx interface displays network quality information in both the Setup tab and Radio tab. The metric that is displayed is the millisecond round-trip time from your device to the RPi and back again. Typically this is under 100ms on non-cellular networks even though anything under 200ms is acceptable. If it is much over 200ms, delay on the audio and control functions may become noticeable. By far the most disruptive network conditions to operating are packet loss and network drops.  If the underlying networks are not reliable enough to provide low packet loss and consistency both audio and control can be adversely affected. RemoteTx is built to automatically reconnect radio control functions when networks drop or change. Audio, though, may need to be restarted manually when underlying networks fail. If all else fails, refresh the browser.

Power Control:

  • RPi Signalling:
    RemoteTx includes control of 3 of the GPIO pins on the RPi.  These can be toggled on and off to control devices connected to these pins. The Iot Relay by Digital Loggers is a great way to control AC power from a RemoteTx RPi. Digital Loggers Iot Relay on Amazon
  • Smart Plug:
    If in the course of operating it is necessary to hard re-boot the RPi it is a good idea to have a way of power cycling it that is independent of it’s own control systems. Recently available Internet controlled Smart Plugs are ideal for this. It is a good idea to have the RPi plugged in to one of these so it can be power cycled remotely from your smart phone if needed. See the Power Accessories Amazon list for ideas.


RemoteTx will work with the RPi on wifi, but isn’t recommended. It is too easy to lose connection unintentionally. It is included, though, so it is possible to remote a radio that is not near a hardwired ethernet network connection.  For example: a radio at a remote site that does not have an Internet connection could be made available via a cellular hotspot.

Tx Timeout function:

If the radio is transmitting, RemoteTx will automatically switch the radio back to receiving under the following scenarios.

  • The operator exits the radio control browser window by either closing it or navigating to another site.
  • The operator changes networks. (Cell phone is switched from cellular data to wifi or visa-versa.)
  • Network connectivity is lost for more than one minute.

Mobile Listening:

Bluetooth your cell phone into your car and listen to your favorite HF net while driving around.