Not all VHF aeroplane radios are made to the same standards….and some can be prone to pack up when you least expect it. Like how? Well, as in many things in life, basically you get what you pay for. A cheap radio can mean cheap performance and reliability.

All plane radios are built to a specification, part of which is the selling price. Cheaper radios often – but not always – use cheap components. Cheaper because their tolerances are lower, there’s a higher fault rate for each batch of components or the circuitry is designed to leave out some potentially more expensive protection systems.

A case in point is voltage ‘spikes’. In the olden days, it was vital to switch off the radio before starting or stopping the aircraft engine. This was to make sure there were no sudden high voltages slamming through the radio. These sudden high voltage ‘spikes’ can wipe out all sorts of bits in the radio.

But modern radios have mostly been designed properly, use good quality components and are not prone to meltdown when you start and stop the engine. Unless….

Here’s an example – the radio works perfectly for a few weeks, even months. Then suddenly it stops transmitting, right in the middle of an approach to land at a busy airfield. You can hear everyone OK but they can’t hear you.

“Oh dear – you’ve had a voltage spike says the manufacturer, it’s damaged our radio. It’s the aircraft wiring/the way you use the radio/the weather’s too hot/too cold/too wet/too dry”. Anything but their fault. But really it is their fault – for using cheap parts and circuits which do not cope with the occasional voltage spike.

We all know who these makers are. But we still want cheap radios, so we risk cheap performance and a maker that isn’t interested in a warranty claim because they say it’s your wiring/weather/engine/airframe maker – anyone but them.

Switch them off I say. Buy a good radio from a well known manufacturer like Garmin, Becker, Icom, Funkwerk, TRIG, Bendix King, Apollo, etc etc. It is a real case of cheap is expensive. One day your life might depend on it.