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2014 Harley-Davidson Street Glide FM Recpetion

Printed From: the12volt.com
Forum Name: Motorcycle Electronics
Forum Discription: Installing Stereos, Alarms, Remote Starters, Lights, Garage Door Openers and other electronics on motorcycles.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=141052
Printed Date: October 15, 2021 at 7:01 PM


Topic: 2014 Harley-Davidson Street Glide FM Recpetion

Posted By: pts760
Subject: 2014 Harley-Davidson Street Glide FM Recpetion
Date Posted: March 21, 2016 at 11:06 PM

I have a customer with a 2014 Harley Street Glide that he had a stereo installed at another shop. They installed 4 speeakers and a 4-channel amp. The amp was mounted behind the ferring to protect it from the elements. By doing so, they placed the amp above the radio. They customer is now complaining that the radio get no local FM stations.

The customer is not going back to the other shop because he has had nothing but problems with them since. I've been doing a little research and think that the radio and the amp are creating either EMI or RFI interferece with each other, in turn, affecting thr FM tuner.

With that being said and leaving the amp in its current location, I was thinking about using a thin sheet of copper to divide the amp and the radio to eliminate any interference between but I've never tried this before. The problematic area is suppose to be blocked by a conductive or magnetic material from what I have read. I assume thats why headunits were copper chassied on high end head units.

Any suggestions or experience with this would be great.

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I drink current, eat ohms, and bleed voltage



Replies:

Posted By: the12volt
Date Posted: March 21, 2016 at 11:14 PM
Have you verified the antenna is correctly plugged into the back of the radio? It's unlikely the amplifier is causing what you described.

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Posted By: pts760
Date Posted: March 21, 2016 at 11:20 PM
I though about that after I finished my last post. I havent pulled the ferring off yet. I've been busy fiberglassing some speaker pods on the bike and the customer approached me with this issue. I was just trying to get a heads up before I dove in and was wondering if anyone else had experience with this.

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I drink current, eat ohms, and bleed voltage




Posted By: the12volt
Date Posted: March 21, 2016 at 11:32 PM
I'd check the obvious first. Chances are it's as simple as that.

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Posted By: pts760
Date Posted: March 21, 2016 at 11:39 PM
I'm gonna do that but for me gaining more knowledge in the EMI/RFI area have you ever dealt with the shielding technique I purposed.

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I drink current, eat ohms, and bleed voltage




Posted By: the12volt
Date Posted: March 21, 2016 at 11:39 PM
Simple test before you take anything apart (no need to have the engine running)... if you can get some FM stations while the radio is on but no AM at all, then it's most likely an antenna issue (probably unplugged). If you get AM and no FM, then there is an issue with the radio itself.

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Posted By: the12volt
Date Posted: March 21, 2016 at 11:53 PM
I'm betting EMI/RFI is not the issue with this one. No, I have never had an issue with mounting an amplifier above a radio causing a decrease in FM reception, and I've done it several times when necessary.

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Posted By: pts760
Date Posted: March 22, 2016 at 12:06 AM
I may sound like a idiot asking this question and sorry to bug you but, what is the theory behind the FM/AM test. I'm not arguing just interested. Why would you only get FM if the antenna is unplugged and why would you get AM and no FM is the radio tuner bad? Wouldn't you recieve no signal at all if the tuner was bad?

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I drink current, eat ohms, and bleed voltage




Posted By: the12volt
Date Posted: March 22, 2016 at 12:17 AM
In metro areas, most tuners will receive some FM channels without an antenna, but absolutely no AM channels without an antenna. If you are receiving AM channels, then you know the antenna is connected. Next time you have a radio on the bench or one on your lap while testing before you mount it, give it a try. This obviously does not apply if you're in the middle of nowhere.

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Posted By: the12volt
Date Posted: March 22, 2016 at 12:27 AM
BTW, if you want to know more, you should study the differences between frequency modulation (FM) and amplitude modulation (AM).

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Posted By: pts760
Date Posted: March 22, 2016 at 12:30 AM
Awesome! Thank you for the info. I really appreciated your help.

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I drink current, eat ohms, and bleed voltage




Posted By: the12volt
Date Posted: March 22, 2016 at 12:35 AM
You're welcome. Let us know how it turns out.

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Posted By: rs specialist
Date Posted: March 22, 2016 at 11:17 AM
If the amp is a class D, which I would assume it was since it is in the fairing then there can be an issue with the amp interfering with the radio reception. I have seen it with multiple companies when the class D amp is mounted near the antenna in the trunk next to the antenna. Nothing short of moving the amp or changing it to a manufacture that has fixed this issue will work.




Posted By: the12volt
Date Posted: March 22, 2016 at 11:49 AM
True, class D amplifiers can be an issue. However, the OP hasn't indicated that it is a class D amplifier. If it is, then the easiest/best solution is to replace the amplifier. If the original install was done by an experienced shop, they would have likely not used a problematic class D amplifier in this application. Again, I'd check the obvious first.



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Posted By: the12volt
Date Posted: March 22, 2016 at 12:22 PM

Here's a recent bulletin updated a couple weeks ago regarding class D ampliiers and antenna placement. on Harley Davidson's.

ISSUE:
Class-D and Class-A/D amplifiers have power supplies that switch on and off at high frequencies, which can emit EMI (Electro-Magnetic Interference) signals into the air. These signals can cause interference with signal processors, wireless devices, and radio waves including AM and FM signals. Modifications in amp designs have been made to keep this to a minimum. However, devices that are in close proximity to the amp can still suffer from such interference.

SOLUTION:
1. Mount the amplifier as far away as possible from the motorcyle’s radio, antenna and antenna cable.

NOTE: Antenna placement seems to be key. Bikes with a rear whip antenna seem to be O.K. Fairing mounted aftermarket antennas do not work when amplifier is mounted to radio.

2. Keep amplifier cables - which carry interfering signals - away from radio, antenna, and antenna cable.

3. Provide a good amplifier ground. Ground cable should run directly to battery. Grounding an amp to motorcycle fairings or forks is insufficient due to higher current requirements of amplifier.

4. Aftermarket tuners are more susceptible than factory tuners to noise issues. Amps mounted close to aftermarket radios have more interference than amps mounted to factory Harley-Davidson radios.

5. Some stations might get skipped by the SCAN function, but if manually tuned, will come in fine.


2014 & NEWER MODELS ONLY:
posted_image2014 factory Harley-Davidson radios have a “Cat Scan” - if not set up right - will not allow tuner scan to stop on all channels. A software reset may unselect previously chosen AM/FM search categories. To resolve, enter “Cat” menu and check each genre to include when scanning radio stations.





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Posted By: pts760
Date Posted: March 22, 2016 at 6:34 PM
Still haven't pulled the fairing but I did try the reception test. It does get am/fm reception inside our interior/exterior tin walled shop...the amp is a new 4-channel Rockford fosgate that I believe is a class d or class a/d. No plausible way to shield the emi without moving the amp? I know moving the amp would proly be the easiest way but the customer doesn't really want to have it relocated

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I drink current, eat ohms, and bleed voltage




Posted By: 2010yoda
Date Posted: January 22, 2020 at 12:47 PM
I have a roadglide with amp against head unit, and another in a saddle bag, reception was terrible, found that it came with a hidden antenna in the fairing, put a new one at the back of the back of bike, all good now..





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