Written at 15:05:56 on Saturday, 2nd December, 2017.
The following safety warnings and disclaimer should be considered when dealing with any information contained on this website.
Australia's electricity supply can deliver fatal shocks. The nominal supply voltage at a household powerpoint is 240 volts. Contact with this at a current flow of only 50mA can kill a healthy adult male in ONE second by inducing a medical condition on your heart known as ventricular fibrillation. Women, children, elderly and infirm people are more at risk. The risk of electrocution increases dramatically when you do not exercise commonsense when handling equipment like antique radios. At times, old electrical equipment is discarded because it develops a fault. It is not easy for beginners and other inexperienced people to ascertain what the fault might be.
Vintage Radios contain transformers which do two jobs. The first is to step-down the mains voltage to supply power to the dial lamps and valve heater filaments. The second job is to step-up the mains voltage to supply a high-tension current flow to the speaker field winding and the tuned circuit. The high-tension voltage is usually somewhere between 350 volts and 1000 volts, depending on the receiver. The current carrying capacity of a high-tension circuit is still strong enough to kill you in the same way that the mains supply can.
Old radio circuits are also connected together with wire insulated with Vulcanised Indian Rubber (VIR) or woven cotton. Both materials perish with age and prove to be quite flimsy when the wire is continually disturbed. Some radios, especially the very early ones, were connected together with small-gauge busbars which were bare! The occasional 1930's set still had some exposed transformer or choke terminals - it pays to learn about these traps before letting fingers wander.
I recommend that you do not touch the workings of a vintage radio receiver unless you know exactly what you are doing. Take time to learn what goes on before you work on them and understand the consequences of complacency. I also recommend that you do not try to use a vintage radio receiver until it has either been checked by yourself (if you are experienced) or you have had an experienced person check it for you. At times previous owners of sets do modifications to them and these present unwary traps for budding collectors. As an example, I have seen a set where a mains plug was used as a terminal for an extension speaker. Old radios were not usually designed to run more than one speaker and doing this work with something that can be plugged into the power is very wrong.
All work on vintage radios should be carried out in a clean, well-lit, well-organised workshop rather than the loungeroom or dining room. You should use either an isolation transformer or an RCD (Residual Current Detector) to provide a degree of protection against electric shock but at the same time you must understand that these devices do not completely protect you. They merely enhance safety and do not replace the need to use commonsense.
You will use any or all information on this website at your own risk. The owner accepts no liability of any kind for any damage to property, personal injury or other losses you or someone else suffers as a result of any actions you take in relation to the use or misuse of any information situated on this website.