Icom 821H setup and PTT?

I’m trying to get Digirig to work with the Icom 821H for FT8 and there doesn 't appear to be anything online. Receive works via the Digirig cable, but I have some questions about PTT for transmit. I understand I can only use RTS for PTT (which seems odd…there’s a perfectly good pin on the Digirig mic cable plug…)

  1. Do I need to cut the connector on the Digirig board for PTT control?
  2. What kind of cable from the Digirig serial port to the CI-V port on the Icom? A simple 3.5mm stereo cable?

I have a separate CI-V cable that controls frequency but the WSJT-X software doesn’t work for it to use RTS to activate PTT on transmit.

Regular stereo cable should be good for CI-V between Digirig’s serial port and transceiver CI-V/remote socket.

You can use PTT by CAT if supported, but usually PTT by RTS is available option in software including WSJT-X since you mentioned FT8. This method does control PTT line in audio cable.

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I cut the traces and soldered the jumpers for CI-V control on the Digirig as per the instructions/video. Now, frequency control works via a TRS cable. However still not PTT via RTS. I measured the voltage and the Digirig is putting out 3.3v at the tip and sleeve.

You must be checking on the serial connector. 3.3V is normal for CI-V.

PTT is on the ring 2 of audio cable. There should be no DC voltage there: sleeve is ground and tip is the audio line decoupled through capacitor. For more info you can check out the schematic at the bottom of this post: