Radio in a caterham?

[davidball]

I can just imagine the shouts of indignation this may generate but I am thinking of fitting a radio to my se7en. I will be touring in the UK this year and I cannot bear the thought of motorway tailbacks without Radio 4! I am toying with the idea of a helmet with internal speakers and the radio speaker cables terminated with a stereo phone socket (attenuated of course). Also a motorcycle style intercom so I can hear my passenger.

Is this legal?

[ewenm]

Legality, I'm not sure, but I guess so as motorcycles use similar setups.

I'd be avoiding the motorways entirely though

[davidball]

Thanks for your opinion. Most of the time I will be avoiding motorways but I will have to use them on a couple of legs on the tour.

[ewenm]

I've got an Autocom setup in mine with rally-style ear-defender headsets. The autocom unit accepts an radio/MP3 input and a phone connection and will turn down the music/radio if you or the passenger speaks or the phone rings. the mics also have a "vox" setting to determine how loud you need to speak before it picks it up - useful for avoiding road noise coming through the mics.

Others have a similar setup with in-helmet mic and headphones.

[davidball]

Great! Thanks for the info.

[Charley Farley]

When I got my 7 from Cat Midlands last year- the original owner had fitted a Sony Head Unit, a wapping great amp in the boot and two rather large speakers in the panel behind the seats.

We kept it in for a while but the speakers had blown and sound quality was awful- (when you could actually hear it) so no point really. So we have taken the head unit out and fitted a 12V Socket which is rather handy with the old Tom-Tom and should be in its element for Classic Le mans.

However, as the speaker 'holes' are still there- i am toying with the idea of picking up a new pair on Flea Bay- a much snmaller 2nd Hand Amp and wiring in my I-Pod.... Not ideal when giving it beans- but handy when pottering along steadily- especially as the speakers are right behind your ears...

[davidball]

I found an old cassette radio with a CD input and spent a day trying to find a place to fit it so it would be out of the rain (I have been told I am a wus for even thinking of using the hood). I finally found a place under the dash on the passenger side so I can now relive my Steel Eye Span days. I still have to find a power out from the first notch on the ignition switch though. I installed a cigar lighter so I can power my pda/gps and a 3.5 mm jack socket for ear phones. I found a motor/cycle intercom kit on ebay for less than 10 quid, bought two crash helmets and am know trying to figure out how to install speakers in them without compromising their structure.
Thanks to you all for the very helpful advice.

[davidball]

I have a suplimentary question.

There is no headphone socket on the cassette/radio so I am having to power the headphone speakers in the helmets from the normal 8 ohm speaker outputs. This is not ideal since it could blow the headphone speakers. I am no audio expert but I think I read somewhere that I can throttle the juice by simply fitting some resistors in line. Anyone know if this is so?

[Gingerbread Man]

From a quick google, It seems that headunit's with Headphone line out sockets are pretty much non existent.

What connections do you have on the back of the headunit?

Any line out sockets that you could convert to a 3.5mm jack?

[davidball]

Hi Thanks for your response. No line out sockets at all. The only outputs are to left and right speakers.

[Gingerbread Man]

Easier to buy a cheap headunit. CD Radio can be had for £50 new.

[davidball]

I agree but I rather like the retro look of the one I have and the ability to play cassettes. I do not think my live axle will allow me to play cds very successfully! I have found a wiring diagramme that shows a setup using 10 ohm resistors and 45 mf capacitors. I will give that a try.

[freerange7]

What about an Ipod Shuffle at £32 ?

[Gingerbread Man]

Yes, how did this go in the end? Any pictures of the finished result?

[1st_petrolhead]

I use an Ipod which is then plugged into an Autocom

[davidball]

Thanks everyone. I am just wiring up the helmet speakers with a coiled lead from a telephone handset (4 ply cable) and a 5 pin din plug. I have fitted two din sockets in to a small black box containing a connector block with resistors wired in. This lets me feed both helmets and maintain the pos/neg connections right back to the output on the radio. As soon as I have installed this in the Cat I will post some photos.

[ramrod69]

I've only just got my first caterham and I did toy with the idea of asking the vendor if the car had a radio for a "joke" but by the sounds of it you lot really do mean it!!! Maybe I am a bit keen on driving rather than listening to some knob on the radio. Anyway whatever floats your boat. Ps if a radio is required for the journey maybe you should choose your other vehicle..Ha ha

[Gingerbread Man]

Update?

[davidball]

Sorry for the lack of update. I still have not had time to wire up the helmets. I may have to take the cat to work on Monday (total transport strike in Belgium) and I could be sitting on the Brussels ring for years so I will need Radio 4 and the Beeb World Service. I will make time this weekend and take the photos as I progress.

[davidball]

Here is the finished project. The bits I used were as small black project box, two black coiled telephone extension cables, two 5-pin DIN sockets and plugs, four 10 OHM resistors and two 45 Mfd capacitors. I wired up according to instructions I got from a very helpful guy on an Electronics forum and the result is shown below.
http://img98.imageshack.us/img98/8996/imag0003dy9....
http://img98.imageshack.us/img98/9441/imag0002jx1....
The two 3.5 mm stereo sockets are for the microphones on the comms set which I have not wired in yet.
The speakers in the helmet were wired to the coiled cable and DIN plug.
http://img98.imageshack.us/img98/9360/imag0006ec2....
The box was connected to the speaker cables from the radio/cassette and mounted on the seat back top between the headrests.
http://img98.imageshack.us/img98/6415/imag0007jo7....
http://img241.imageshack.us/img241/2314/imag0009yc...
The radio was mounted under the dashboard on the passenger side.
http://img241.imageshack.us/img241/6240/imag0004yt...
http://img98.imageshack.us/img98/3448/imag0005np2....
http://img241.imageshack.us/img241/7937/imag0014am...
The bits cost about 40 Euros. It works ok but I have not yet tried to connect the output from the comms unit to the helmet speakers. The only difficult bit was the soldering. I had to ducktape my wrist to the desktop to stop my hand shaking when I was soldering the resistors etc to the DIN sockets. Old age sucks!

Edited by davidball on Saturday 4th October 13:45