The little Opal is now successfully working at 20 Mhz. Over the weekend I will try 22 Mhz, 24 Mhz and 30 Mhz, though I suspect the limit is 22 or 24.

In any case, I don't see any advantage at all in going beyond about 27 Mhz, since the way the levels are configured on this machine, to be able to use level WG7 as a tournament level, you would need to go all the way to 40 Mhz, which is impossible. But with 27 Mhz, and you can use level WG6 as the tournament level and get move averages of just under 3 minutes per move.

I will report back if my house does not burn down first