21-08-2020, 08:59 PM
I haven't seen an AM-only car radio for sale since the early '80s. Almost anything you find second-hand - ignoring obviously vintage stuff - will do FM, and should be pretty cheap. The vintage stuff might cost more because people want the authentic radio for their classic cars.
Don't be confused by the term "head unit". I can see how there is an implication that there might be more behind it, but that's usually not the case - almost everything you can buy will be self-contained, complete with amplifiers, etc. Just connect to the power supply, aerial, and whatever speakers you have - job done!
Some of them have phono sockets on the rear, implying that they need to be combined with separate amplifiers. Usually, there will be internal amplifiers; the phono sockets are just there for those who choose to use more powerful amplification - in which case they can be safely ignored. But it's a 2 minute job to check the spec, of course.
For many years now, they have contained 4 channels of amplification - 2 speakers in the front, 2 in the rear. That doesn't mean you have to use all 4 - you could just use one if that's all you can accommodate in the tractor. Just make sure the unused leads are well-insulated, as they sit at half the supply voltage*, and the output amplifiers will likely be damaged by accidental shorts...
*: Because they are usually bridged. If so, each amplifier will be quite powerful - perhaps around 16 real watts into 4 ohms. With decent speakers, there will be plenty of volume to overcome the worst of the engine noise.
The old radios - the ones with two knobs on either side - were called "DIN D". They were superseded during the late '70s/early '80s by what you see today - slightly larger, and a simple rectangle leaving the manufacturer to decide where knobs, etc, could go. These are called "DIN E". The Sony set that I linked to is an example of that form factor. Subsequently, they came out with "Double DIN" - that's what the larger radios that you'll see on my first link are. There's a few words about all this here: https://en.wikipedia.org/wiki/ISO_7736
Just because a modern radio comes with Bluetooth, USB slots, and perhaps slots for memory cards (like you have in your digital camera), that doesn't mean you have to use them, and there's no reason why they should be a problem. Just ignore them. A car radio is still a car radio! But if you think that will confuse the person using it, just pick up something s/h that pre-dates all these modern features. A radio/cassette or radio/CD player from the 1990s might well be a good bet, and won't cost much. But you mentioned DAB - something that is modern enough to have DAB might well have some of these other facilities. As I say, just ignore them.
It's a shame you're asking now. I had 3 sets that I could have given you. Two nice Sony units were given away, and the other (a decent Pioneer) went to the scrap yard with the car - it wasn't worth pulling it out. Frankly, depending on what's local to you, a visit to a scrapyard might be the quickest and easiest thing to do...
Or perhaps something like this might be better: https://www.screwfix.com/p/stanley-sy360...-snr/54182
Given how noisy the tractor almost certainly is, adding a loud car radio to the mix wouldn't be my first choice - and as it's a workplace, the HSE might well have a view on this. These will knock quite a bit of that noise down, and he'll be able to hear the radio more clearly without damaging his hearing any more than it might already be. Those were just the first result I found - many other options exist.
Don't be confused by the term "head unit". I can see how there is an implication that there might be more behind it, but that's usually not the case - almost everything you can buy will be self-contained, complete with amplifiers, etc. Just connect to the power supply, aerial, and whatever speakers you have - job done!
Some of them have phono sockets on the rear, implying that they need to be combined with separate amplifiers. Usually, there will be internal amplifiers; the phono sockets are just there for those who choose to use more powerful amplification - in which case they can be safely ignored. But it's a 2 minute job to check the spec, of course.
For many years now, they have contained 4 channels of amplification - 2 speakers in the front, 2 in the rear. That doesn't mean you have to use all 4 - you could just use one if that's all you can accommodate in the tractor. Just make sure the unused leads are well-insulated, as they sit at half the supply voltage*, and the output amplifiers will likely be damaged by accidental shorts...
*: Because they are usually bridged. If so, each amplifier will be quite powerful - perhaps around 16 real watts into 4 ohms. With decent speakers, there will be plenty of volume to overcome the worst of the engine noise.
The old radios - the ones with two knobs on either side - were called "DIN D". They were superseded during the late '70s/early '80s by what you see today - slightly larger, and a simple rectangle leaving the manufacturer to decide where knobs, etc, could go. These are called "DIN E". The Sony set that I linked to is an example of that form factor. Subsequently, they came out with "Double DIN" - that's what the larger radios that you'll see on my first link are. There's a few words about all this here: https://en.wikipedia.org/wiki/ISO_7736
Just because a modern radio comes with Bluetooth, USB slots, and perhaps slots for memory cards (like you have in your digital camera), that doesn't mean you have to use them, and there's no reason why they should be a problem. Just ignore them. A car radio is still a car radio! But if you think that will confuse the person using it, just pick up something s/h that pre-dates all these modern features. A radio/cassette or radio/CD player from the 1990s might well be a good bet, and won't cost much. But you mentioned DAB - something that is modern enough to have DAB might well have some of these other facilities. As I say, just ignore them.
It's a shame you're asking now. I had 3 sets that I could have given you. Two nice Sony units were given away, and the other (a decent Pioneer) went to the scrap yard with the car - it wasn't worth pulling it out. Frankly, depending on what's local to you, a visit to a scrapyard might be the quickest and easiest thing to do...
Or perhaps something like this might be better: https://www.screwfix.com/p/stanley-sy360...-snr/54182
Given how noisy the tractor almost certainly is, adding a loud car radio to the mix wouldn't be my first choice - and as it's a workplace, the HSE might well have a view on this. These will knock quite a bit of that noise down, and he'll be able to hear the radio more clearly without damaging his hearing any more than it might already be. Those were just the first result I found - many other options exist.
