Two Slices - Am I Doing this Correctly?

W4JBB

On my 6400, I am attempting to have one slice that is voice and one that is data for SHARES. Output power is set at 100 W. I was trying to adjust output power by which slice is transmitting (i.e. 100 W for voice, 30 W for data). If there's a way to do that, I haven't figured it out.

What I did find in the Flex Community was not to adjust my transmit power but to adjust Tx gain in the DAX control window for the slice that's transmitting data. I seem to be able to adjust my output power by doing this. My transmit level is roughly halfway between -10 and 0... around a -6 or so and my output RF power (in SmartSDR) is about 30 - 40 W.

When I switch back to the voice slice, my transmit power seems correct according to the RF power meter in SmartSDR - it's voice... It peaks at about 80 W or so and I'm fine with that.

Is adjusting the Tx gain in the DAX control window the proper way to adjust data transmissions?

Thanks,

Joel - W4JBB/NNB4JB

Andrew O'Brien

Usually, the suggestion to adjust the audio gain, rather that transmit power, is accompanied by the suggestion to monitor your ALC levels with data modes. Set the transmit to maximum (or what you think will be sufficient for the intended purpose) and watch your ALC as you increase the TX gain in DAX, aim for about "zero" on the ALC gauge.

Andy K3UK

John KB4DU

Since the actual data signal is audio, not digital data, adjusting the tx audio controls the transmit power, kind of like speaking softly into the mike or speaking louder. More tx audio, more power out. Less tx audio, less power out. Although we call these digital modes, the digital processing encodes and decodes the data, but the actual rf signal is audio within the voice frequency range.