My banana chips didn't go crispy. Not even after 30 hours.
My replacement dehydrator book arrived today (the original one got lost in the post). It mentioned 8 hours for drying banana slices, and mentioned chewy. Nothing about crispy, snappable, chips.
I googled why arent my banana chips crispy dehydrator (or something like that) and found pages of people bemoaning their inability to get crispy banana chips.
There is even information from Excalibur saying that it is not possible to get crisp banana chips in a dehydrator.
It appears the chips have to be fried before drying.
I'm going to try frying some courgettes (as I have an abundance of those) and then drying them.
Meanwhile, I've tested the temperature of the dryer using a probe thermometer. Spot on!
And the dehydrator book contains a number of recipes for dehydrator macaroons... very interesting.