sorry for not replying sooner, but I was away on a customer site then off on holiday last week.
I have found that the TechCons for 2017 and 2018 are available in VLE but I assume you have to have a subscription to be able to download them https://learning.osisoft.com/Labs/Subscriptions .
I was interested in a Techcon from 2016. That is available under standard TechSupport File downloads if you filter on training materials (also all the other lab workbooks).
Took a while to find this but hopefully it will save others time in the future.