Theory of operation:

Reproducing CW timing through the Internet has always been difficult because of the unreliable packet delivery of the Internet. The RemoteTx audio system, though, delivers audio precisely. This can be used to send audio CW tones from a PC to a remote radio (via RemoteTx RPi) and generate reliable CW transmissions. At the remote radio/RPi, a USB sound card that has VOX triggering is used to key the CW key jack.

The approach is as follows:

• AT REMOTE PC:
  A CW keyer that emits CW audio sidetines is plugged into a PC sound card that is set as the default microphone of the RemoteTx audio connection.
  (Winkeyer WKUSB-AF or Ham-Gadgets Pico Keyer are good options)
• AT RADIO STATION WITH RemoteTx RPI:
  A Ham-Interfaces or SignaLink USB Audio device with VOX triggering circuit is used to trigger the radio’s key input. When a CW audio tone is received from the remote PC, the VOX PTT is triggered which is fed into the radio CW key input which in turn keys the radio. The radio key setting is set to straight key.
  The radio phones jack is also connected to the VOX USB sound card line in, so that RX CW can be heard on the remote PC.
  RemoteTx now has custom built Ham-Interfaces VOX/CW adapters for this solution available.

 

 

 

List of Materials:

HamGadgets KEYER FOR REMOTE PC:
https://hamgadgets.com/UPK-Ultra-Pico-Keyer-Built_p_31.html

VOX / PTT CIRCUIT FOR RADIO:
https://www.ham-interfaces.com/product-page/digimode-3-micro-yaesu-built-in-usb-sound-card-and-vox-ptt
RemoteTx now has custom built ham-interfaces VOX sound cards on hand that easily plug into the key and phones jacks of radios. Please contact RemoteTx.

SOUND CARD FOR REMOTE PC:
https://www.amazon.com/dp/B00IRVQ0F8/

3.5 MM SPLITTER:
https://www.amazon.com/dp/B07CZYRPG9

3.5 MM male/male adapter:
https://www.amazon.com/dp/B0CPDFRZ4H

Audio Mixer:
https://www.amazon.com/dp/B0824Q3WY8

MINI SPEAKER FOR REMOTE PC SIDETONE:
https://www.amazon.com/gp/product/B007OYAVLI/

 

EXAMPLE SIDETONE-KEYER SETUP: