G3TSO
FT707 Top Band modification
1983
FT707 Top Band modification
The greatest shortcoming of the FT707 was the lack of top band. This modification adds the missing band and uses the blank space on the bandswitch to facilitate selection.
The modification was published in the Radcom magazine.
Before commencing this modification I approached Yaesu who advised against doing it. They claimed the PA could not operate on the band yet the same PA unit was fitted to the FT107. I obtained a set of 160 metre coils from Yaesu for the FT107 and use them to replace the 12 metre coils. The 10m coils were adjusted to cover 12 metres as well. I added an additional Xtal oscillator for 160m and fitted an additional LPF in the rear of the radio for 160m. The results were excellent. Additionally, I arranged to switch off the Receiver RF stage so as to make it usable on 40 metres at night. The RF stage was switched on and off via the redundant FIX switch.