Your radio was working well but it suddenly died. So, what do you do? You come to the conclusion that’s it’s probably a valve. It’s always a faulty valve, isn’t it? What else could it be? Armed with a screwdriver, you make your first mistake…
MISTAKE No 1.
You take the back off the radio.
Your first mistake could be fatal. There are high voltages inside your radio which are extremely dangerous and can kill.
MISTAKE No 2.
You look at the valves and decide that one or more are faulty because they’re not lighting up.
Your second mistake is to assume that all valves light up brightly. Some perfectly good valves hardly light up at all so the absence of a warm glow means nothing.
MISTAKE No 3.
One or more valves might look black inside, or silvery like a mirror, so you conclude that they need replacing.
Your third mistake is understandable. Surely, a good valve won’t look burnt and black inside the glass? Look at the photos below… Despite their appearance, they are all perfectly good valves.
I’ve known people replace all the valves in their radio for one or more reasons I’ve mentioned and, to their surprise, and cost, the radio still didn’t work. Even a valve which rattles can work perfectly well. Having said that, valves shouldn’t be tapped, hit or rattled. There’s one more mistake people make, and that’s swapping the valves around in an effort to miraculously bring the radio back to life. All valves are different and this action could result in damaging what were perfectly good valves.
I don’t sell valves. My stock is for customers’ radio repairs and, if I start selling valves, I’ll only have to replace them. If you need a valve, then look on one of the auction sites. There are people there who specialise in valves so you should be able to find the one you’re looking for.
Do you really need to replace a valve? I rarely have to replace valves because the originals, from the 1940s and early 50s, are still going strong and have many years left in them. Also, the original valves are often better than the new ones available these days! If you do have to buy a replacement, try and find a ‘new old stock’ valve or even a good used one.