Beogram 4004 Type 5526: Electrical & Mechanical Work Complete...First Play Test

I will begin this post with a picture of the Beogram 4004's first play test. It feels great to listen to some Stevie Ray Vaughan playing while I compose the blog report.

To get to this point from the last post I had to install the two Beolover replacement LED modules for the speed trimmer indicator lamps and run the 24 hour platter speed stability test.

Here are some pictures of the speed indicator LED replacement.

The LED lamp replacements on this speed trimmer circuit reduce the load on the Beogram motor control enough to show up as a final improvement on the 24 hour speed stability test. This of course goes hand in hand with the Beolover restoration of the DC platter motor, new trimmers on the main board and the new RPM speed selection relay.

Here are two plots of the 24 hours speed tests I performed on this Beogram motor. The first one, back in May, was with the Beogram before any restoration. The second plot, from the last 24 hours, shows the dramatic difference in the platter speed test results after the completed mechanical and electrical restoration work.

Beogram 4002 Type 5513: RPM Trimmer Panel

Along with the tangential arm assembly work I also performed the restoration steps on the RPM trimmer panel. Beolover's tests have shown that this update reduces the heat load of the platter motor control circuit and improves the motor stability.

Here is the original trimmer assembly with the two original lamps.

The Beolover replacement LED lamp assemblies are designed to connect to the same solder pads as the original lamps so no board modifications are needed. As with all of the Beolover replacement parts a person could change back to the original parts if they wanted to. The new LED light modules have a specific right and left.

A small strip of double sided tape separates the LED board from the trimmer panel board. Here are the new LED lamps installed.

Testing of the new lamps will have to wait until I get the rest of the tangential arm assembly updates done.