Jump to content

Fm Transmitter interference>


Recommended Posts

Hello all! I've been decorating 26 years and finally to put my display to music. All has gone well so far except my transmitter tests! The audio transmits but there is a humming or buzzing in the background. The more you turn the radio up the louder the sound gets. This happens no matter what station I select. I am using the whole house transmitter 3.0. Any suggestions will be appreciated. Also the sound is perfect inside the house when I listen on the computers speakers.

Link to post
Share on other sites

Welcome to the forum.

I agree with Tom, sometimes just moving it a hair can clear it up.

Now, gonna tell you a longer story, just to be sure.... I started with the same Whole House transmitter. Used it 2 years & another forum user even used it last year when last minute his went out. It was fine. Pretty clear - as long as within a few houses of it's position. I then upgraded mine to the Rubber Ducky. Wow - last year was crystal clear. This year's Halloween was crystal clear. Then 2 days ago, when I started testing for Christmas - holly macaroni - static out the whazoo... Terrified, I started moving, adjusting, unplugging - re-plugging... Ugh. Static. My son was leaving to go on an errand. When he returned, he said it was crystal clear all the way _____ (can't tell you how far as the FCC probably wouldn't approve..) Anyway, it was my truck's radio and not the transmitter.

So all this to say, check it with another radio too.

Good luck.

  • Like 1
Link to post
Share on other sites

before I switched to my current unit I also found that depending what else is on the circuit can create a hum.  I'm not smart enough to understand why, but when it was plugged into a cheap power bar or an outlet that had an appliance I had noticeable background hum.  

Link to post
Share on other sites
32 minutes ago, Mega Arch said:

Welcome to the forum.

How rude of me. I didn't even notice it was the OPs first post on the forum.

So... Welcome aboard this crazy train. Lots of great folks here with lots of great knowledge. You're in good hands here.

Link to post
Share on other sites

Here is one thing with my fm setup. I get a hum if I use the headphone jack on my computer and it gets totally clear when I use the line out jack instead. Somebody brought up before about the headphone jack being amplified and the line out jack not.

Link to post
Share on other sites

Thank You all for the comments and welcomes. Weather you know it or not you all have helped me so much as I have been reading many posts in this forum and learning from you all. A little bit of an update. I had a audio splitter bought from light o rama sending signal to my speakers and the transmitter. I unplugged the speakers and plugged the transmitters line directly into the computer without the splitter, this seems to have reduced the sound by 90 percent. not sure whats up there but it works for now. Any additional comments are welcome. Please post if anyone has more suggestions. I'm still curious why I cant plug both in at the same time. Still, im going to buy a different transmitter in case the one I have now stops working or has issues again. Nothing wrong in having a back up. thinking about the mobile black box I've seen in some other posts and videos.

Link to post
Share on other sites
3 hours ago, FremontLights said:

Tthis seems to have reduced the sound by 90 percent. not sure whats up there but it works for now. Any additional comments are welcome. Please post if anyone has more suggestions. 

If you haven't already, try adjusting the sound level of the computer output and the power level of the transmitter, if it has one.

Link to post
Share on other sites

Chances are it wasn't the splitter but the speakers causing the problem. Plugging in the speakers through the circuit out of balance introducing the 60 cycle hum. try it with the splitter and no speakers to see if it  hums,  then you'll have your answer where the problem is. if it's the speaker's you can try a different set of speakers. Or if you know what you're doing  a well-placed ground wire will probably solve that as well

Link to post
Share on other sites

So the other thing you can do to see where the hum is getting introduced is to unplug all audio input at the transmitter and then see if you have any hum on the radio, the transmitter will still be transmitting just will not be transmitting any outside sources you will have dead air so if all hum is gone then it is an issue with your cables feeding it. If you still have hum then it is an issue with the transmitter, could be dirty power going into the transmitter or the transmitter to close to other electronics giving it interference. You can try moving the transmitter to a different location or try plugging it into a noise filter. Maybe you need a ferrite on the power line or the audio cable feeding the transmitter. Just some of my thoughts. Good luck.

Sent from my XT1254 using Tapatalk

  • Like 1
Link to post
Share on other sites

I have another transmitter question:  I have an EDM with RDS capability, which I have used for several years, with perfect operation.  This year there is a buzzing sound that is broadcast only when the transmitter is sending out an RDS signal.  It took me some time to narrow it to the RDS output, but I think that is when it is happening.  Quite annoying!  Anyone have any ideas?  I have never heard it in previous years.  I have actually had a few people ask me this season what the noise is at the beginning of each song.  Thanks for your help!

Link to post
Share on other sites

My only guess is that the audio is a little higher than in the past.  Drop your audio just a little bit and see what it does.

 

Link to post
Share on other sites

That helped a bit, but it's still there and I can't lower the audio too much more, or people will have to have their radios really high.  I monitor with a radio indoors, instead of speakers, so I can know exactly what people hear in their cars.

Link to post
Share on other sites
16 minutes ago, CKSedg said:

I monitor with a radio indoors, instead of speakers, so I can know exactly what people hear in their cars.

That is totally false monitoring right there.

What you hear at the house could most likely be different from the street. Believe me. I know.

Car radios from the street receive differently than from the home.

Link to post
Share on other sites

Yes, technically you are probably correct.  I also go out in my car every few days to see what is happening.  Still, I have the buzzing issue when RDS files are transmitted.

 

Link to post
Share on other sites

There are so many ways that unwanted humming/buzzing can get into a transmitter system that you could shotgun all day and not find it. A couple of things to eliminate. Flourescent lighting or LED/curlique bulbs. The audio input line running parallel to and next to a 110 volt line. The other day I found a problem that has bugged me for years. Any Radio on AM or FM had a 60 hz buzz except in certain areas. I found that it was caused by a charger for my wireless drill batteries. Nothing was being charged, but it was still plugged in, therefore running. This is common with a switching power supply. All of these things can allow the hum/buzzing into the transmitter input resulting in a constant background noise. 

Isolate the transmitter from all powered items and power lines. (Worth a shot).

Link to post
Share on other sites

I havent read everything above but if you have your computer output turned up to much that can also cause a hum... or back feed from a near by speaker, or even your computer if it is setting to close to it or some other electrical device.  also try moving your reciever a little farther away from your transmitter if you are monitoring it threw one. 

Cell phone charger, batteries chargers and any near by electrical devices can cause interference or even if you happen to have say a magnet in the area... can also cause noise problems.

If you have street lights... maybe the city changed the bulb and that is what is causing the noise.. 

Link to post
Share on other sites
11 hours ago, CKSedg said:

That helped a bit, but it's still there and I can't lower the audio too much more, or people will have to have their radios really high.

I would suggest during the day (so you are not bothering someone trying to watch the show) that you turn the audio level down a little more and see if you can get the buzz to go away.  If that makes it go away, your problem is likely that the overall modulation with the RDS data running is too high.  I've never looked into how much of a change in modulation the RDS data adds - something I'll likely check if I ever add that capability (it's in the plan)...

 

Link to post
Share on other sites

I resolved that buzzing issue I was getting last year on my MBB Eclipse, I had used a splitter off the sound card output jack to split it one to the transmitter and one to the computer speakers which were amplified.  Several things I did, I bought a second splitter and ran the amplified speakers from it, it also fed the outdoor speakers I had had set up. 

I used a second splitter that went directly to the FM transmitter and a second set of non-amplified computer speakers.  On the audio cords to  from the computer to the amplified speakers, and from the computer to the FM Transmitter and non-amplified speakers I used baluns to help cut the noise levels down, they were used on each end of the audio cables near the male plugs.  

The baluns are also known as ferrite coils, they snap on and over the audio wires near the male plugs at each end.   This not only cut down, but eradicated the buzzing and some erratic static that crept in from time to time.   Gave me a clear signal all the way, and I also use a rubby duck style antenna, it's what gives me the best results on the transmitter.

  • Like 1
Link to post
Share on other sites
  • 2 weeks later...

Sorry I did not get back sooner to everyone. Thank You for all the helpful advice!!! My lights went on this last Sunday the 4th with no problems.  I believe the issue was the audio cord followed my bundle of main extension cords from the house. I have the transmitter about 125 feet from the house in order to reach the street. I moved the audio cord away from the extension cords and that seems to have done the trick. This is a great community to be a part of and I'm sure I'll be posting again. lol

  • Like 1
Link to post
Share on other sites

Although you seem to have resolved the majority of your hum this post is for other people.  The cheaper transmitters like the whole house transmitter (I call it the whole garage transmitter :-)  are really prone to having problems with AC line (60 Hz) hum.  It is often injected through the ac line into the transmitter.  You should try taking the wall wart and wrapping about 7-8 loops of its wire tightly around the wall wart and keeping it there with a rubber band or cable tie.  This will shorten your wire length by about a foot, but well worth it.  I find that it typically cuts the hum easily in half.

 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...