HT 25-19 HF Transistor data

[Amper]

Hi!

First of all im sorry to open a thread for this kind of topic, but i have found other people in other places not getting answers to this question, so i decided to try here anyway.
I have several 13,65MHz power amp boards and i would like to know what they are capable of. They are built around two power trasistors each marked

Code: [Select]

C
HT 25-19
9021

I could not find any documents on the web related to them.

Does anyone have some info?
It should be around 50V operating voltage and 200W Pout.
Im mostly interested in the maximum voltage, is there some way of determining that by careful measurement non destructively?