PowerGenius XL - PTT Options?

There are two basic ways to do what you are trying to do. 1) keep PTT from keying the AMP while the tuner is tuning.  2) Prevent the flow of RF from the radio while the tuner is tuning.  Most people go to the first idea first, but the issue here is that the radio can still put out 40-50W which will go through the amplifier if it's PTT is not enabled.  I think the better way of doing this is to run a line from the Palstar to the FLEX-6000 TXREQ input line.  You will have to enable the input and set the polarity in SmartSDR or the Maestro.  Then when you key the radio, it will assert PTT which will tell everyone you want to transmit, but no RF will be emitted until the TXREQ line is released.  

The same goes for a SteppIR or anything that potentially is adjusting and needs to have RF held up until it is finished tuning. This is also how amplifiers can hold off RF if they need a longer time to key after receiving PTT.