A set of 160 metre Inductors were purchased from Yaesu as replacement parts for the FT107. The 12 metre BPF coils were replaced with the 160 metre coils; an additional Xtal Oscillator was added to the Osc Board, and a 160 metre LPF squeezed into the PA compartment.
Top Band Xtal Osc Top Band LPF
The 10 metre BPF was then retuned to cover 12 metres as well; no bands were lost and 160 metres was included on the unused position of the bandswitch. Finally, diode switches were added so that the Receiver RF amplifier can be turned off; the difference on 40 metres at night is astounding! This was wired to operate using the FIX switch.
My initial apprehension of this modification was initiated by Yaesu who had told me that conversion was not possible, because the PA was not designed to operate on 160 metres; this seemed quite odd as the same PA unit is fitted to the FT107 which includes 160m. The conversion provided a new lease of life to the 707and completed the round about route to mobile operation on that band. The only snag is that now I had 2 home brew transceivers and the 707 all on top band!