VA2SFN, this is a little late to the party but have you read through this thread? Are you using a Digirig Lite or a Digirig Mobile? The Lite is not going to work for you and you need a Mobile. The PTT pin on the radio is shared with the microphone up/down buttons. There needs to be ZERO Ohms from PTT to Ground to transmit. Any resistance will instead cause an up or down function instead. The Lite has a limiting resistor between PTT and Ground and will cause this.