Hi Siggi,
I tried my very early PG506 with a 7904 / 7A29 or 7A16p / 7B92A. I can't measure any jitter between the trigger output and the fast rise outputs at the 50-100psec level. The rise time of the high amplitude output into 50ohm is about 10nsec and due to the time delay between the trigger and high amplitude pulse I have to use the delayed sweep on the 7B92A to get to 1nsec/div so more uncertainty but the jitter is at the 100ps or less level. 1.5nsec sounds like something badly wrong.
Roger
