Fc-20 Autotuner - Yaesu FT-100 Undocumented

After modification
There is also a software work-around to get the fans running on 2 and 70 on RX only,
by using the 'SPL" button and VFO A/B to turn on the SPLIT function.:
• Set the VFO "A" on the RX QRG on 2m or 70cm band and VFO "B" on a TX
frequency on HF or 6m.
• Briefly press the TX PTT (which briefly transmits on HF or 6m)
• Now the fans are running full speed and will slow down in a few seconds without
stopping entirely.

FC-20 Autotuner

The FC-20 auto tuner is available as an accessory for the FT-100. The FC-20 was
designed specifically for the FT-847 and FT-100 and is intimately mated to them. The
FC-20 is capable of matching a SWR up to 3 to 1. It features 100 memories that
memorize your favorite frequencies so that when you return to them, the unit can
"instantly" tune to a frequency without having to evaluate the SWR as it tunes.
People have identified two limitations to the FC-20: the matching range and the inability
to use both CAT control and the tuner simultaneously. If you don't need a wide matching
24