FM TRANSMITTER CAUSING LOUD HUM IN SPEAKERS

[Vince4xmas]

I swapped by old WholeHouse FM transmitter out this year with a new CZH-05B. Transmitter work great however I also run an amplifier and 2 speakers. This new FM transmitter, once powered on, creates a major hum in my speakers. I tried setting the CZH-05B to low power, but saw no change. I can move the audio input cable to the transmitter around as well as the entire transmitter and get less hum but doesnt go away.

I am using a G3 director and the audio out from the G3 goes to a splitter where on audio cable goes to amplifier and the other to the FM transmitter.

Do I need to install some sort of filter?

I could move the FM transmitter to a location far away but I still need a long audio cord to the G3.

Anyone else having this issue? Please advise.

[k6ccc]

If RF is creating interference in your amplifier, the best solution is distance. Move the transmitter or antenna away from the audio amplifier.

Sent from my Droid Turbo via Tapatalk, so blame any typos or spelling errors on Android

[dgrant]

Usually when you get AC hum like that, its a broken wire for the ground side of the transmission antenna. Also, a non-shielded cable from the transmitter to the antenna, can also cause this. 

[jrock_at_rons]

I'm not sure if its the same issue, but last year (after I have switched to my "new"/old computer) I had an issue where the sound was fine via headphones, output speakers, etc., except when it was being transmitted.  I too thought it was an RF issue so I tried moving the transmitter further away, etc., but I would still get this static when I would listen on my car's radios.  

For me, it turned out to be a SoundlBlaster setting for 'bass boost' that was distorting the sound when I would output the sound to the FM transmitter.  I turned off all these specialized sound settings on my laptop and voila, it transmitted crystal clear.  

Like I said, your issue sounds a bit different, but I figured I'd post my calamity and solution in case your leads with AC hum dry up.   

[PhilMassey]

As dgrant says, often can be a ground issue from a broken ground or a ground loop.

An audio isolation transformer like this

https://www.amazon.com/Mpow-Ground-Isolator-Stereo-System/dp/B019393MV2/ref=sr_1_1?ie=UTF8&qid=1478110811&sr=8-1&keywords=audio+isolation+transformer

between the source and the transmitter can sometimes cure a ground loop induced hum.

[jerry72]

I bought one of those CZH transmitters, sent it right back. I had nothing but static and hum, every thing i did would not fix it. Went back to my cheap ole FM02

[BMurray]

I have one and have no hum.  All my cables: audio,  cat5e,  and power are all zip tied together across one area (must be 10+ cords).  When I initially set up for Halloween I had a very loud hum and static but it turned out to be the audio cord wasn't plugged all the way into the 3.5mm input jack.  Once I re-seated the plug all was well.  

[Vince4xmas]

Looks like I found a solution to my issue. Thought I would share with others:

 

http://forums.planetchristmas.com/index.php?/topic/38794-addition-fm-transmitter-humbackground-noise-fix/

[Mr. P]

One thing I have noticed with my particular setup or it may just be my particular computer, don't use the headphone port to output to your fm transmitter. The headphone port signal is amplified and creates distortion through the transmitter. Ultimately you would want to go with a line out port as the signal is not amplified and is much cleaner.

[gsmith37064]

I had the same issue with the hum in the speakers. Turned out that my PC sound was louder than 50%. Brought the PC volume down to around 40% and it resolved the hum. Also fixed the static when playing from a radio. Now i get crystal clear stereo music.