Penn State does not routinely operate on OpenSky. They maintain their own radio systems at their campuses or, in some locations, operate on county systems as mentioned above. PSU Main shares the trunked system with Centre County.
This page explains the status PSU has:
https://en.wikipedia.org/wiki/Commonwealth_System_of_Higher_Education
PSU and the other three public universities listed on that page (Temple, Lincoln, and Pitt) are in a different category than the "real" state universities. These four receive some funding assistance from the state but are not state entities.
The other universities are under the SSHE umbrella, are actually owned by the state, and include East Stroudsburg, Kutztown, West Chester, Cheyney, Lock Haven, Mansfield, Clarion, Slippery Rock, Shippensburg, Indiana, Bloomsburg, Edinboro, and California Universities.
As far as I know, none of the SSHE schools use the OpenSky, either, even though they are a state entity.