03-09-2022, 08:52 PM
Hi Jim ! Welcome to the Phorum. The service data for the model 610 can be found in the library of the main site. Here is the link... https://philcoradio.com/library/download...l.%201.pdf
As you can see, looking at the schematic, the tube used originally is the type 80, a very common full wave rectifier used right up unto the 1940s. It uses a 4 pin base with this pin out...
[Image: https://64.media.tumblr.com/2e59a8fcee06...77b1b1.jpg]
The 5Z3 has the same 4 pin base and the same pin out, and can be used as a substitute in most cases for a type 80. This was probably done in the 1950s or 1960s by a service man who had the 5Z3 on hand but no type 80 which was by then considered obsolete.
[Image: https://64.media.tumblr.com/709e5bbc008e...12b82a.jpg]
As you can see, looking at the schematic, the tube used originally is the type 80, a very common full wave rectifier used right up unto the 1940s. It uses a 4 pin base with this pin out...
[Image: https://64.media.tumblr.com/2e59a8fcee06...77b1b1.jpg]
The 5Z3 has the same 4 pin base and the same pin out, and can be used as a substitute in most cases for a type 80. This was probably done in the 1950s or 1960s by a service man who had the 5Z3 on hand but no type 80 which was by then considered obsolete.
[Image: https://64.media.tumblr.com/709e5bbc008e...12b82a.jpg]
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
