Is there a mars modification that can be done on the Yaesu FT-991A that will open up the full US 70cm band, From 420.000 MHz to 430.000 MHz, because for some reason that portion of the band is locked?
There is not an approved mars mod that does what you desire. Yaesu’s approved Mars Mod opens 1.8 to 30 mhz continuously, but does not change 6M, 2M, or 440 (70CM).
Well what is the unapproved mare mod that will fix this? I’m not asking for illegal frequencies I’m wanting frequencies that we are allowed to use.
You may want to contact Yaesu Support or one of many amateur radio equipment repair locations/individuals.
Either you have a non-US version OR you installed non-US firmware. Try installing the US firmware and ensure you perform a factory reset afterwards (very important).
73
Yaesu doesn’t know that the US has 420 to 430MHz privileges, as all of their radios have that blocked.
@Robert_Smotherman
You are correct. The FCC US band plan for 70cm is 420 - 450, while the Yaesu FT-991A receives 420 - 470 but only transmits 430 - 450. The Yaesu FT-991A does not transmit on 420–430 MHz because it is designed to comply with International Telecommunication Union (ITU) Region 2 (Americas) amateur radio band plan. Even the Mars Mod, approved by Yaesu does not affect the 70cm band in the Yaesu 991a.
You should also note that the Icom 2730a, the Icom 7000, and the Icom 705 also only transmit between 430 - 450mhz.