Sony Tuner Timer TT-3000

[RKnight]

A few years ago I was on the lookout for a Betamax recorder and came across an auction for one. This one in particular was the portable Sony SL-3000 and in a separate auction was the companion tuner timer unit, the TT-3000.

I placed a bid on both thinking it might be useful to have the tuner unit as it can power the recorder just in case I couldn’t power the recorder on its own.

Anyway I won the tuner and lost the recorder, so I was stuck with what was essentially clock with a tuner in it.

I tried to sell the thing on but the only interest I got was someone in India, but was put off by the £100 shipping charge. So it went into the loft for 6 months or so until I decided to do something with it.

I can't find the picture of the unit working as a whole, but i'll put that up if I can find it.

[RKnight]

These are the pictures of the clock which will be put together but I haven't decided the best way to do this.
The clock panel on the front is purely the VFD and the buttons to control the clock.
The actual circuitry which operates the clock is on a large PCB which is a pain; as if I put it behind the front panel it will stick out.

What I did find was a battery which had leaked and made a mess on the board which I thought was rechargeable but appears not to hold a charge and becomes warm if I pass current through it.

I measured the battery connections on the board and with no battery there is 6.2V at the terminals and to 4.2V when I connect a rechargeable battery but the current passing is only 1mA which is next to useless.

The clock board will run happily on a single 12V supply and the VFD runs from a 3V centre tapped supply from the original transformer.

To test the function of the battery I connected a 4.5V supply to the battery terminals on the board and measured the current when the 12V supply was disconnected. When the board operates from the battery only there is a slight squeal from a component on the board and the current jumps to 200mA.
I noticed that the VFD will still operate if the original transformer remains plugged in.

[RKnight]

According to a spec sheet available on http://www.mrbetamax.com/SL-3100TwelfthPage.htm# it states that there was a 60 minute battery backup which I assume was rechargeable in the past but due to the age the charging circuit is damaged.

I once powered the clock up into 12 hour mode where AM and PM could be displayed, but I only got that once.
I imagine that there is procedure for powering up the clock in 12 hour mode as opposed to 24 hour and I managed to find it, or trick it with a lower voltage while I was testing.

I've attached a picture of a closeup of the VFD, the original transformer and the old battery.

[RKnight]

The tuner was easier to assemble and consisted of three main boards about the same length as each other which was glued to a piece of wood. The tuner panel sits at the top, the output connections will be attached at the back and at the front is the channel selection.

While I was taking boards out and measuring voltages, I found that the tuner requires a 60V supply as do the channel selection neons.

I was able to find 60V on the original transformer so I rectified and smoothed it and with a computer power supply unit (for 12V and 5V) I was able to make the tuner unit work.

There was a problem with the unit before I dismantled it where the neons didn't glow when the unit was cold but after a good half hour or so, they started to glow dimly and then got brighter.
I also had tuning drift problems originally which must have been caused by a fault on the original power supply board, probably a capacitor.

[RKnight]

Here are some shots of the tuner in operation.

The last picture shows the circuit boards and heatsinks which are no longer required.
The unit could supply 2.6A at 12V for an external camera and also the recorder which explains the large heatsinks and big transformer.