EB5AGV's Workbench: Tono Theta 5000 restoration

A top-class and classic terminal

Tono 5000

This page is devoted to the restoration of my Tono Theta 5000E terminal. I hope you enjoy it!

Tono Theta 5000

Complete, automatic send/receive of Morse code (CW), Baudot code (RTTY) and ASCII code (RTTY) with the addition of any video monitor for display. The Perfect addition to complement any amateur radio installation. Below are a few of its outstanding features:

Lots more info about this unit can be found here: TONO THETA 5000 - specifications


Unit as received

I got the unit in unworking condition, having a known fault, and without keyboard. But, besides this, it was extremely dirty of tar from a really heavy smoker. It was lots worse than the pictures show, trust me!

Tono 5000

Tono 5000

Tono 5000

Tono 5000

Tono 5000

Tono 5000

Just to show how bad the tar layer was, here you have some samples of what is below it:

Tono 5000

Tono 5000

Once the main board was removed, I found all metal case was... well, look at it:

Tono 5000

The power supply was below a large dust and tar layer:

Tono 5000

And, of course, picture tube neck, which gets pretty hot, was completely darkened with baked tar residue:

Tono 5000

Flyback and other parts were also badly affected:

Tono 5000

See what is below the layer!

Tono 5000

This is a detail of the power supply assembly, once removed from its place. Really ugly looking!!!

Tono 5000

But beauty is sometimes in the inner side:

Tono 5000


Cleaning

So it was time to clean the unit... armed with alcohol, cotton swabs, rags, paper towels, patience and so on.

After lots of hours, these are the results. Now you can look at the chassis!

Tono 5000

The picture tube had been cleaned but not fully:

Tono 5000

This is the tube and the monitor assembly properly cleaned:

Tono 5000

Tono 5000

Tono 5000

And the power supply is now looking fine!. I replaced the rectifier bridge, as it was faulty:

Tono 5000

Tono 5000

General look of the unit before putting back main board:

Tono 5000

What took more time to clean was the main board, as it has lots of components and access to the board is pretty limited between them. But result is good:

Tono 5000

This is the unit with all modules back on it:

Tono 5000


Testing

OK, now that unit was assembled, it was time for an smoke test!

First power on...

Tono 5000

Well, at least it powers up. GREAT!!!

Tono 5000

I need to clean the switches and pots, as they are all electrically very dirty. And check the unit with some on-air signals...


More to come soon... keep tuned!


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