On any transmitter that utilizes a module 9Z, 9C, 8U, etc, it is best to range test with the "largest" section of the antenna out of the transmitter. This would be the section nearest the transmitter when fully extended. This helps to dissipate any heat build up in the transmitter thus protecting the internal electronics.
I hope you find this information helpful. You can also reach our Futaba support technical team at 217-398-8970, or via fax at 217-398-7721.
Sincerely,
Krysta
Lead Futaba Customer Service and Programming Technician
Also you may want to check our Website at (
http://www.futaba-rc.com)