some questions about old crt camera view finders

I acquired a pair old crt camera view finders from an electronics surplus store, but before i go hog wild with my soldering iron i have a couple questions. how many amps dose one of these things usually draw? will goofman's mini tv instructable work with any crt or do some crt's not work?

NachoMahma8 years ago
. Locate the part number on the CRT and search for a data sheet. It will tell you voltage/current/&c. Compare specs to CRT in goofman's circuit.