View Full Version : Hearing the radio through my speakers


gukachu
05-20-2011, 03:39 AM
Hi all.. I have a Sony GX9ES stereo receiver and I can always hear the same radio station through the speakers; especially during silent/quiet parts of music or if I turn the volume down. I can hear it no matter what source I switch it to. Any ideas/suggestions as to what is going on or what I should do to remedy this? Your help is greatly appreciated, thanks!

budgetaudio6
05-20-2011, 03:44 AM
Send me your unit! It needs proper disposal. Good thing im a repository for all things old audio....:D....i mean ouch! Im the trash heap...pm me for adDress! PLEASE!

jUST BLEED THROUGH FROM YOU FM SECTION TO THE AMP SECTION. THE ES MONIKOR APPARENTLY ISNT LIVING TO ITS NAME?
(oops)

century tek
05-20-2011, 03:46 AM
It's called RF interference. Poorly shielded cables can contribute to said cause, but other contributing factors can cause this.

catman
05-20-2011, 03:52 AM
G'day mate, yes it sounds like RF 'breakthrough' type of interference. Ferrite 'clamp on' chokes (available from electronics hobbyists shops) placed on various leads should help.

Is the broadcast station on AM or FM as different approaches to solve the problem may be needed depending on the radio 'frequency' of the station. Regards, Felix (vk4fuq) aka catman.

Renzor213
05-20-2011, 08:03 AM
Judging from your discription, does sound like you're picking up a local powerful AM radio station, with something in your system acting as a detector circuit. As already mentioned, the ferrite core's are worth trying. Also good idea, using top quality 100% shield RCA interconnect's, short as possible. You can also try some small .1uf capacitor's accross the speaker terminal's, but to big and you'll start filtering off treble. Your's is a pretty common problem if a ham operator in the area. Even heard of a guy living close to a TV station, and flourescent lamp's would glow, not being hooked up to anything.

guiller
05-20-2011, 09:56 AM
You could perhaps play a bit with your system and look for changes on the interference: e.g, change RCA interconnects, switch both legs of the AC plug in (if possible), change AC plug location, etc. Tracking down the origin of the interference may need some patience on your side.

js1138
05-20-2011, 10:11 AM
In my one experience with this it happened through the phono input. That input has the most amplification.

wizargoz
05-20-2011, 11:11 AM
Make a tin-foil helmet, which will intercept the RF signal and prevent cranial leakage...

Radioboy
05-20-2011, 12:34 PM
I always look back to the 500kw days of 700 WLW whenever I think of RF interference.......

If it's always the same one, Do you know what station is getting into your system? Do you live close to an AM xmtr site?

mfhale
05-20-2011, 12:55 PM
in my one experience with this it happened through the phono input. That input has the most amplification.

+1...

stereofanboy
05-20-2011, 01:09 PM
I've never heard my radio through anything but my speakers. What did you expect, to hear it through your toothbrush?

mfhale
05-20-2011, 02:11 PM
I've never heard my radio through anything but my speakers. What did you expect, to hear it through your toothbrush?

http://www.amazon.com/Tooth-Tunes-Musical-Toothbrush-Night/dp/B000N5R7KS

gukachu
05-22-2011, 03:52 PM
It's an FM station.. 92.7 here in San Francisco to be exact. Doesn't seem to matter whether I run shorter runs of blue jeans interconnects or longer runs of lower quality acoustic research interconnects. Sorry I don't know much more about the cables than that.

For speaker cables I'm running diy made from hard drive cables http://www.tnt-audio.com/clinica/flatter_e.html I'm using the 32 pole variant.

In my new room I'm having to use long runs of extension cord from the wall outlet to my system. They are of super generic Walgreens quality. I also don't have any kind of line conditioner.

I don't know if this helps at all.. but I really appreciate your feedback, thanks!

Herr Eickhorn
05-23-2011, 12:29 AM
I've never heard my radio through anything but my speakers. What did you expect, to hear it through your toothbrush?

Well, actually not a toothbrush but tooth fillings. It has been documented that certain types of tooth fillings can act as an antenna and pick up audible radio signals. Do a Google search and you will see I'm not kidding.

In fact, the best rendition of Space Cowboy (Steve Miller Band) I ever heard was after a dentist installed a particularly complex temporary silver amalgam filling in one of my back molars in the 1970's. I was clearly able to pick up FM radio station KY-102 in Kansas City. My only complaint was that the sound was a little metallic. If it would of been more like tubes I would of kept the filling. Has anyone else experienced this phenomena?

tdat7192
05-23-2011, 10:05 AM
LOL with a mouth full of fillings, I never have picked up radio.
It might be bleed through of the amp itself. If you have a spare set of little speakers and a portable source, you may want to try taking the amp to another location, hook up source and speakers and see if it still happens. If so, then very likely the amp bleed through. The one time I have seen this was also with a turntable. You may want to disconnect various sources, one at a time to see if they are the contributor. In the case of the turntable, be sure to remove the ground as well. Good luck!
Do you at least like the station? :)

dr*audio
05-23-2011, 11:24 AM
The first step is to find out where the rf is getting in. Disconnect all the cables going to the receiver, and put it on Aux input. Do you hear the station now?

gukachu
05-28-2011, 02:09 AM
The first step is to find out where the rf is getting in. Disconnect all the cables going to the receiver, and put it on Aux input. Do you hear the station now?

Yes, I still hear it. I noticed that when I put my hands near the speaker cable or actually grab it then it starts to go away.. my speaker cables are flat, wide ribbon cables; nearly 2" wide. Are these acting like big antennae for rf?

woodj
05-28-2011, 10:48 AM
Methinks ribbon cables would make dandy FM antennae.
Just curious, other than you had them handy, or you want to keep things flat, why are you using those?
You could test by replacing those with lamp/zip cord temporarily and see what happens (although that too might produce similar results), then proceed from there.

electronjohn
05-28-2011, 10:56 AM
From your description...my guess is the speaker cables. Sub another set & see what happens.

uxwbill
05-28-2011, 10:57 AM
I've never heard my radio through anything but my speakers. What did you expect, to hear it through your toothbrush?
What are you talking about? I've always listened to the radio on my toothbrush and now you're telling me that isn't supposed to work? I am very confused! :D

I've noticed that on some of my stereo receivers, faint audio from the tuner section continues to be audible at higher volume levels with any other input selected. This is particularly true of my slimline Technics receivers, especially when they are set to tape monitor mode.

If the OP is hearing the radio through their speakers and it isn't a by-product of the tuner, I'm with the others in thinking that they have something which is acting as a crude detector "circuit". Does this continue when the set is turned off? Going through the wiring, disconnecting it piece by piece and listening for the effect to stop should help determine what the likely cause is. When you find it, using something like ferrite beads or simply rerouting the cable may help.

uxwbill
05-28-2011, 11:04 AM
I was clearly able to pick up FM radio station KY-102 in Kansas City. My only complaint was that the sound was a little metallic. If it would of been more like tubes I would of kept the filling. Has anyone else experienced this phenomena?
No, I haven't. That is pretty wild. I'm kind of surprised you would be able to "tune" an FM station in that way, since the frequency would shift around based on the material being broadcast. AM seems the much more likely candidate for unlikely reception...

How did you "perceive" this broadcast?