RE: Best way to range check with 9Z
The 9Z transmitter antenna doesn't have a wire to it. It makes contact with special wiper contacts at the antenna ball on the top of the transmitter. The antenna doesn't make proper contact with the circuitry until the large, bottom section is pulled out until it "clicks".
A good range check with the first section extended, with the model's engine running and not running should give you the conficence you need for flight.