I would buy an old dubble beam scope at "blocket" or eBay. Don't pay to much (1000sek max) and start to mess around with it. Soon you will know what/if you need something else.
If you are working on stuff connected to the Mains (you say tubes..) make sure you know what you are doing when connecting scope test leads.
If you don't have a transformer for the DUT this might be a good time to stop and read up on safety issues when working with high voltage.
There are people on this forum who know about these things a million times better than me though
If you are working on stuff connected to the Mains (you say tubes..) make sure you know what you are doing when connecting scope test leads.
If you don't have a transformer for the DUT this might be a good time to stop and read up on safety issues when working with high voltage.
There are people on this forum who know about these things a million times better than me though