On Monday, February 8, 2016 at 8:43:46 AM UTC-5, Surge wrote:
On Monday, 8 February 2016 15:29:53 UTC+2, Tango Whisky wrote:
The FSG16 is an almost 40 years old design. At the time, the channels/frequencies were stabilized with one dedicated quartz per frequency, and the FSG16 was designed to hold 12 quartzes. Simple as that.

So 12 individual crystals was a cheaper solution than being able to tune into any of the 720 usable channels that the rest of the receiver unit is capable of?

Correct, same for many radios (including RC radio's). The hardware could cover a wide range, but it was the crystals that did the actual tuning.
Later radios did all this without "crystals" and could also do smaller steps in between freq's.