THE PROBLEM

Some early AC/DC radios, the Bush DAC90A, for example, use 3.5 Volt 0.15 Amp dial light bulbs. The problem is that these bulbs are no longer manufactured. Even if they were still available, they were so dim that they did nothing to light up the dial. The Bush DAC90 is even worse with only one dial light bulb.

It is possible to use a series resistor or voltage divider network to drop the mains voltage to suit readily available 6.3 Volt bulbs, but resistors get very hot. It is also possible to change the value of the original shunt resistor across the bulbs in the DAC90A, but that can cause more problems. I love the warm glow of the lamps from the radio dial so, I looked for a solution.

THE SOLUTION

I've found a source of 6 Volt transformers which will power two 6.3 Volt dial light bulbs nicely. The encapsulated transformers create virtually no heat and are physically small, fitting inside most radios without making any permanent modifications to the chassis or wiring. The bulbs will give a constant brightness and light up the dial beautifully. So, what are the benefits?

THE BENEFITS

The bulbs will be at full brightness from switch on with no dimming or slowly reaching a dull glow as the radio warms up. Apart from the obvious benefit of having a decently lit dial, the other advantages are numerous. Firstly, 6.3 Volt bulbs are inexpensive and readily obtainable. With the original design, the shunt resistor will become very hot if the dial lamps fail, and some radios will not work at all if one or both lamps fail. With the transformer fitted, there will be less heat generated inside the radio and, should the bulbs fail, the radio will still work with no detrimental effects such as overheating. If one bulb fails, the other will still work.

THIS IS AN EASILY REVERSABLE MODIFICATION

There is no permanent modification required to your radio. The last thing you want is to devalue your vintage radio by permanently modifying it. The radio can be put back to its original design at any time simply by removing the transformer, swapping a couple of wires around and fitting the original bulbs.

THE COST

The cost of supplying and fitting the new transformer and bulbs to your radio will be in the region £20, depending on the type of radio you have. I now have the transformers and bulbs in stock, so email me or give me a ring and arrange to bring your radio over for this truly effective and worthwhile modification.

CUT THE COST IN HALF

I can cut the cost down to £10 if you'd like me to carry out the modification when I service your radio.