Static On My Radio

[JoeFromSD]

Folks, my computer and modem is plugged into the wall and on the other side is the bedroom which is on the same circuit. I need to turn both off every night or else can't listen to the clock radio with all the static and screeching. I still get the static though even after shutting down the computer and modem.

I've tried unplugging the radio and just using the battery power.

How can I troubleshoot where the static is coming from??

 

[kellys_eye]

Energy saving lights (CFL or LED) are often culprits. You have to go around and systematically switch equipment and lights off to locate the source.

There will be 'many' sources though but you'll eventually find the one(s) that are particularly problematic and can either change them to non-interference prone versions (change LED back to filament for example) or just switch them off.

Also try rotating your radio - sometimes the pickup is 'directional' and a lot of the interference may be eliminated by moving the radio slightly.

 

[JoeFromSD]

Thanks Kelly! I've never gotten advice from a Scott before

I do have one light on at night but it's in another room maybe 40' away from the radio. Could that make the static from that distance away?

 

[kellys_eye]

I'm actually a Yorkshire man but married a Scot lassie - Nessie I reckon - but the interference can indeed travel along the wiring if it's a particularly poor example of electronic design i.e. many cheap Chinese knock-off lights are poorly designed and even more respectable makes fail to include adequate noise suppression.

I have the same kind of problem when using my ham radio equipment - despite it being located away from the main house I find myself returning there to find a noisy source that stops me receiving weak signals.

It's modern day 'pollution' and increasingly problematic. You'll be surprised to discover the number of devices that incorporate switched-mode power supplies - the main culprits.

Let the thread know what you find - such searches sometimes throw up 'unusual' results.

 

[JoeFromSD]

I read that computers use that switched-mode power supply. I notice a light inside my computer even after I've shut down, could that cause the static?

 

[Gryd3]

I read that computers use that switched-mode power supply. I notice a light inside my computer even after I've shut down, could that cause the static?

Your computer will never actually be 'off' (Is in no drawn power)
Shutting down the operating system will turn off the peripherals and most of the main-board, but the Power Supply and a couple of essentials on the board will always run.
Unplug it, or turn the little switch off on the back to kill power.
If your radio has batteries, you could also walk around the house to determine which areas are worse than others... that may help identify what is causing the issues.

(it might also be a neighbor.)

 

[JoeFromSD]

OK, it's coming from a new cord I got for my monitor!

the cord's AC adapter has a sliding switch on the side, with 7 settings. The top one is 24V, the bottom one 12V. The static is worse on the higher numbers.

I've never seen these different settings on a power cord before, what number should I be using for the monitor?? Seems to work just fine using any of them.

I have that cord plugged into the an outlet, and on the other side of the wall is the outlet where I plug in the radio.

thanks for the Info guys!

 

[davenn]

I've never seen these different settings on a power cord before, what number should I be using for the monitor?? Seems to work just fine using any of them.

there should be a label on the monitor stating it's power requirements

powering it with too higher voltage risks killing the monitor

 

[JoeFromSD]

Right on, it says 19V so that's where it'll stay!

 

[Gryd3]

OK, it's coming from a new cord I got for my monitor!

the cord's AC adapter has a sliding switch on the side, with 7 settings. The top one is 24V, the bottom one 12V. The static is worse on the higher numbers.

I've never seen these different settings on a power cord before, what number should I be using for the monitor?? Seems to work just fine using any of them.

I have that cord plugged into the an outlet, and on the other side of the wall is the outlet where I plug in the radio.

thanks for the Info guys!

Sounds like one of those multi-purpose adapters from RadioShack. Power supplies can be horrendous noise producers. Glad you found the culprit, and hope you didnt damage your monitor...
Changing the voltage, or using adapters with an incorrect voltage or polarity may cause immediate and irreversible damage to whatever it may be connected to.

 

[JoeFromSD]

would plugging the monitor's cord into one of those power strips with noise suppression, help or eliminate the static??

I already have the radio on other side of wall plugged into one and that doesn't help

 

[davenn]

would plugging the monitor's cord into one of those power strips with noise suppression, help or eliminate the static??

it may help if the noise generated by the PSU is going back into the mains power cable and being radiated from there

if it is being radiated directly by the PSU ( and most likely is) then no

there is a small chance that a little of the interference is coming from the PSU mains power lead

 

[kellys_eye]

You may have seen some power cables - especially to PC-type equipment - with 'fat lumps of plastic' attached to them. These are ferrite cores intended to help reduce the interference passing back to the mains supply lines.

Putting a 'loop' of mains cable through a suitable core may make a difference (where there isn't one originally) but not always.

It's a modern-day 'plague' for those that use radio equipment but once you're aware of its existence you start to make efforts to curtail it! The power pack that's causing the problem with your monitor could be resolved by using an analogue PSU (transformer, rectifier, smoothing etc) rather than the SMPS currently in use - depends on how seriously you take the issue.

Wandering around with your radio (as someone mentioned above) is a good way to familiarise yourself with potential sources of noise so you can return to them later if the problem becomes more specific for you.