RESTORATION OF A 1959 BUSH TV85                                                                                                 Page 2


The big smoothing capacitor is put back into the set. A new mains-rated block shaped capacitor replaces the original waxed tubular next to it.


All the control potentiometers in this set are now opened and waxoyl applied to their tracks. This is done to make for more reliable operation in the long term. Here, a cotton bud is being used to anoint the track of one of the frame linearity pots.

The remains of the old broken mains inlet has been removed and a large washer drilled with mounting holes, to act as a bearing plate for the large sleeved grommet. This grommet has to be made up from various grommet parts and rubber rings to hand.

The HT metal rectifier can be seen beneath. This will be left alone - for now. I'll see how it performs in the finished, working set before deciding whether replacement is necessary.

A start is made on replacing and/or reforming the main run of capacitors.

It proved possible to reform both of thses electrolytics rather than replace them, so this aspect will continue to look original. One of these is dated 1959, matching the year of the set.

Here's the underneath of the I.F. chassis. All the waxed tubulars and black Hunts capacitors here were replaced with new. Then the resistors' values were checked.

There will now be a break for the weekend, while I switch to Detinnitiser development work.

Come Monday, I work through replacing the waxed tubular capacitors atop the IF panel, and, after turning the chassis over, the tubular capacitors the other side - shown here.

Some have slightly awkward values...


... like this monster here. This, designated C96 in the service sheet, couples the live end of the heater chain to the high tension rail. A similar capacitor is seen in other Bushes - for example the TV22.

Its function is somewhat mysterious, but presumably it is intended to provide hum neutralisation by one way or another.

The necessary replacement capacitors are ordered from RS, and should arrive tomorrow.

Here is C96 on the circuit diagram, circled in red. What do you think?

Across my well-worn workbench are strewn the valves. All these will now be tested and, if they pass, will be cleaned up to look like the new ones fitted alongside them.

In the event, several are revealed as faulty. The EY86 EHT rectifier has an open-circuit heater, and one of the PCF80s (now getting rare) is low, as is one of the PCL82 output valves. All are replaced.

Here we see the EBF89 (sound IF amp) under test, which it passes with flying colours.

The new complete set of good valves are now all plugged in to the cleaned-up chassis.

In this view, we can see into the line output transformer's box (to the right). A cover plate will hide this.

Tomorrow, reassembly and fitment of the tube will be undertaken and it'll start to look like a television chassis again!

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