High Voltage Forum
General Chat => Laboratories, Equipment and Tools => Topic started by: Mads Barnkob on September 25, 2022, 03:18:22 PM
-
The previous owner of this Danish vintage oscilloscope had tried to plug it in and the only result was smoke! I was asked if I wanted it for repair or it would be thrown out. The Radiometer Copenhagen OSG 42b was repaired and saved!
/>
The outside with controls, screen and inputs
[ Invalid Attachment ] [ Invalid Attachment ]
The inside reveals a beautiful construction technique. All tube sockets, strip lines and components are mounted on both sides of a base plate in the middle, with the CRT crossing through diagonally. High voltage transformer is located at the bottom and the input stage is shielded off from the rest.
[ Invalid Attachment ] [ Invalid Attachment ]
It turned out that 4x dual 20uF/450V electrolytic capacitors were defective, one of them had sprayed its dielectric all over the inside. It was replaced by newer/desoldered 33uF/450V electrolytic capacitors. The small transformer would not be able to handle larger capacitance that we normally use in smooth capacitance in modern power supplies with less ripple.
[ Invalid Attachment ] [ Invalid Attachment ] [ Invalid Attachment ]
-
That easy...
Electrolytes from the 50ies , well...