Not extending the antenna of any modular radio, whether it is synthesized or not can harm the module with excessive heat build up if left this way for any length of time.
Having the antenna fully retracted MAY not harm the module for short periods of time, but to be on the safe side, again, with any radio that utilizes a module, it is suggested to have the thickest portion out.
The 100+ feet of range is valid with the antenna's first segement out.
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
ORIGINAL: DaddySam
Hello Krysta
Okay, but just out of curiousity is it because of the synthesizing module? I did read the manual, but I bought my radio before the synth module became available, and it clearly states that the Tx antenna be all the way in and the range be 100+ feet. So if I have the thickest section extended, do I need to look for more range, or is the 100 feet still a valid test? If the antenna being out is a requirement for the synth module, may I suggest that Futaba include a small addendum to the instruction sheet that comes with the module?
Thanks,
Sam