I scanned the two pages of the PL-368 manual which explain the ETM function and have attached them here. It is the same as the PL-330 ETM and I have attached that entire manual for other details, many of which are the same. Recent Tecsuns share many similarities so this should give you the info you want.
I just got my PL-368 and will write it up fully after a few weeks of testing and comparisons.
Let me know if I can provide any more info...my review is in progress.