hopz Posted August 9, 2009 Share Posted August 9, 2009 I found this cute little battery powered AM/FM/WB radio... Sony. Works great with head phones- in the house. Have intentions of putting it on the bike and I was poking around looking for a good place to mount it. Tried the radio with the bike running and have nasty loud squeal. Radio is there but behind the noise. Same noise with ignition on but not started... any thoughts on how to fix this? Works fine on FM, and I think the WB does too but I might be wrong about the WB. Maybe just use the FM band? Link to comment
smiller Posted August 9, 2009 Share Posted August 9, 2009 I'm afraid there aren't many practical solutions when it comes to radiated interference. Usually the best soloution is eliminating such noise at the source but in this case the source is your entire CANbus electrical system so not much you can do about that. If relocating the unit doesn't help about all you can do is find some FM stations that you like... Link to comment
Bernie Posted August 9, 2009 Share Posted August 9, 2009 Have you tried to locate it in the tank bag? Maybe you can stick it into your jacket pocket. I know that if I route the headset leads for the AutoCom inside the frame rails below the seat from the rear to the front of seat, I will get all kind of noise, but if I route the wires outside of the body work and tuck it under the left edge of the front seat. The noises are gone. I think the bike battery is transmitting a lot of these noises. Link to comment
Tony_K Posted August 9, 2009 Share Posted August 9, 2009 I think the bike battery is transmitting a lot of these noises. Um, no. Bikes (in this case) are equipped with a wonderful little power plant called a Alternator which in turn creates a magnetic field with electromagnetic interference also know as... ta da! radio frequency interference. So the AM band gets compromised by this interference. The field output can be reduced with extensive shielding but it's not worth it for AM! Link to comment
hopz Posted August 10, 2009 Author Share Posted August 10, 2009 I concur with all the comments- thanks. The good news is that Rush is now on am FM station here so all is not lost... unless I leave town. Link to comment
NoHeat Posted August 10, 2009 Share Posted August 10, 2009 Do you have an HID light? I'm thinking of that because it would be on when you have the ignition on but the engine is not running. I'm not sure, but I think the power for an HID light is AC that makes use of a switching power supply with a frequency of about 20kHz. If that's so, it might generate harmonics in the AM band, which is about 100kHz. Link to comment
hopz Posted August 10, 2009 Author Share Posted August 10, 2009 Sorry- no HID... The noise appears as soon as the ignition comes on, and even before engine start...fuel pump maybe? What if I wrap the entire motor in aluminum foil...? Link to comment
der Wanderer Posted August 10, 2009 Share Posted August 10, 2009 I think the interference in question is karma from the entire universe when you tune to that particular radio station... Link to comment
smiller Posted August 10, 2009 Share Posted August 10, 2009 The good news is that Rush is now on am FM station here so all is not lost... unless I leave town. Maybe that squealing noise you heard on AM was Rush... Link to comment
realshelby Posted August 10, 2009 Share Posted August 10, 2009 Fuel pumps are notorious noise makers in modern vehicles. But, it should go away moments after you turn the key to on if you do not start the engine. Metal fuel tanks, capacitors, are used to combat the fuel pump noise but almost none of the fixes are easily adapted to a motorcycle. Because your Sony is meant to be carried on a person as a portable device it is likely not built with any shielding for interference like would be found in/on a motor vehicle. Link to comment
der Wanderer Posted August 10, 2009 Share Posted August 10, 2009 How about placing a shield between the radio and the rest of the bike? Something like the pierced panel in the door of a microwave? I'd have it horizontal in the top case or maybe bottom of a tank case, with the radio above it, to avoid blocking 180 degrees (or half the world, varying based on your bearing). May not work perfectly, have corner effects, reduce the radio efficiency, etc, but better than nothing. Link to comment
bobbybob Posted August 10, 2009 Share Posted August 10, 2009 I found this cute little battery powered AM/FM/WB radio... Sony. Works great with head phones- in the house. Have intentions of putting it on the bike and I was poking around looking for a good place to mount it. Tried the radio with the bike running and have nasty loud squeal. Radio is there but behind the noise. Same noise with ignition on but not started... any thoughts on how to fix this? Works fine on FM, and I think the WB does too but I might be wrong about the WB. Maybe just use the FM band? Are you running it through an autocom? If so, is it being powered off the bike's electrical system? If not, then it's not a ground loop, which is where I was going with this. Most likely RF interference caused by 1) radar detector 2) another radio receiver or transmitter of some type 3) bike's onboard electronics. Link to comment
hopz Posted August 11, 2009 Author Share Posted August 11, 2009 As I mentioned, this is not an Autocom issue. The interference begins when the ignition key is turned ON and/or when the motor is running. AAA Battery power... Sony earphones. Key ON=Noise. Key OFF, no noise. Only on AM band. Link to comment
NoHeat Posted August 11, 2009 Share Posted August 11, 2009 fuel pump maybe? If you had an oilhead, I could suggest pulling the fuel-pump fuse or the fuel-pump relay, and if that doesn't identify the problem, pulling more fuses until you found the culprit. But you have an R1200, and I don't know anything about diagnosing with CanBus instead of fuseboxes. Link to comment
Tom B Posted August 11, 2009 Share Posted August 11, 2009 Using an AM radio on a bike is not going to be easy, as it will be very sensitive to the bikes electrical noise. It is sometimes easy to cure electrical noise that’s coming up a power lead, but airborne electrical noise is not so easy to cure. You can’t just shield the radio because that would stop the radio signal as well as the airborne electrical noise. So the only thing left is to try to shield the bikes electrical noise getting to (and contaminating) the radio signal, which is not easy to do. Things you could try, if you really think its worth it! Get an FM radio, probably not what you wanted to hear! Make sure all the HT leads and plugs are suppressed Custom make metal shielding covers to go over the HT coils and make sure these are a tight fit and bolted (or bonded) to ground (the bikes frame or battery negative terminal) this can sometimes help a lot, after all it would be part of the radio fitting kit for a BMW bike! Make sure the radio is mounted as far away from the HT leads/coils/plugs as possible. Perhaps on the bikes handle bars? If possible, try making a suitable remote antenna for the radio and mounting that somewhere far away (like the moon!) and then you can perhaps shield the radio??? but then it may be difficult re-tuning etc, and the chances are electrical interference will still be picked up by the remote antenna? Make sure you are tuned only into STRONG radio signals You may also need to fit a suitable noise filter across the fuel pump 12 volt supply Other things that can sometimes help, for example; on a Triumph Daytona there is a heat shield mat fitted between the engine and fuel tank, and this heat shield has a metal foil to one side, which if EARTHED to the battery negative terminal massively reduces airborne electrical interference, which otherwise radiates from the HT leads/coils onto the bikes tank and then contaminates most radio signals. Sometimes if you can earth the bikes metal fuel tank is has the same effect. Sometimes some of this will work ok on one bike, but on the next bike it doesn’t work quite so well? Not always a practical solution, but I knew of one customer who recorded his radio show each day and then listened to it from a tape player the next? If you want to bike power the radio, find and use an in-line 12 volt power filter (like our part 2439) to help prevent electrical noise coming up the power lead. (AM radios are very sensitive to this sort of thing) and if bike powered you will also require an ISOLATION interface lead to your Autocom, so using batteries is probably best as you should not need to use power filters or isolation interface lead to the radio. If you like solving problems and have plenty of time, this could be an interesting project. But if you don’t have time or don’t like to be disappointed then go for the easy route and used a different audio device. Autocom UK Tom Link to comment
bobbybob Posted August 11, 2009 Share Posted August 11, 2009 As I mentioned, this is not an Autocom issue. The interference begins when the ignition key is turned ON and/or when the motor is running. AAA Battery power... Sony earphones. Key ON=Noise. Key OFF, no noise. Only on AM band. Sorry Hopz, did not see any reference to not being Autocom in your posts. But TomB is correct about AM frequencies--they are just too close in the frequency "bands" to ignition sparks and other RF inteference, plus the "amplitude modulation" mode for AM opens the door to all RF noise, where the "frequency modulation" mode for FM closes that door. AM is measured in KC (kilocycles) while FM in MC (megacycles)--huge difference in the way they work. CB radios are also afflicted by the same issues; FRS/GMRS frequencies solves the issue. Link to comment
hopz Posted August 11, 2009 Author Share Posted August 11, 2009 Thanks Tom... and all others... I found that if I press the little button that says "FM" or even the one that says "WB" it goes away pretty good. Link to comment
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