Baffled by the occasional weirdness of your guitar amplifier picking up AM radio stations? In this article, we delve into the strange spectacle of guitar amps picking up the radio and provide multiple troubleshooting options with solutions to keep your amp radio-signal free.
If you look into the construction of an AM radio receiver, you will realize how different factors can cause this problem. Additionally, this problem is also prevalent in certain studio equipment like sound systems and speakers.
Radiohead fans may laugh at the wordplay of it, and bands like RATM have actually used this ‘interference’ in one of their tracks. Nevertheless, for most people, a guitar amp picking up the radio can be a major annoyance when you are trying to woodshed your way to glory. But what causes this strange and peculiar phenomenon and what can be done to stop it?
Why do guitar amps pickup radio stations?
According to experts, the main reason for any amplifier picking up radio stations is faulty or poor shielding of the electronics cavity. The casing of your guitar cord (jack) and the pickup pots behave like antennae. They will pick up and amplify the local radio signals that then play through the guitar amplifier.
Most of the time, these radio airwave issues will boil down to these four primary suspects:
Guitar amp: All amps are made to work as input AND output speakers. Simplistically speaking, they are designed to capture and produce any type of sound. Very often an electronic item within a certain radius of the amplifier can cause interference and result in the amp picking up and amplifying varying levels of sounds. Usually, this is avoided by good shielding, but that isn’t the case with budget amps or faulty/defected lavish ones.
Guitar Cable: Guitar cables, especially cheap ones, can act as an antenna and pick up airwaves at a certain frequency that your amp speaker is amplifying. A broken spot in the shielding of a cable can cause the aforementioned effect. Any cable carrying 115 VAC (voltage AC power) will overwhelm the incoming radio signal and quash it. In most of the cases, a high quality guitar cable like the Mogami Gold or a Fender 20’ Pro Series Cable should easily sort out this issue. However, if the interference occurs even when the cable is not plugged in, the problem might be in the amp or its grounding.
Power Cord: Power cords are rarely an issue but you cannot rule out the possibility if the problem persists. It is time to thoroughly investigate the power cord of your amplifier to see if it is causing this problem. If you are using an older cord or a cord that cannot sufficiently power the amplifier, it can cause airwave interference. You can upgrade it and get a new power cord to check if that solves the problem. Make sure that your new cord has the standard 18AWG diameter (American Wire Gauge). You can try the C2G Standard or the Chanzon AC Cord on Amazon.
Grounding: The fourth – most elusive suspect – could be the apartment’s A/C wiring. An old apartment that skipped grounding or the retrofit grounding in old buildings is always a possibility. In theory, your amp has a ground and the outlet has a ground, but in practice, it is possible that it is not connected or the wiring is faulty. This could be the problem area and you can cross-check this by either taking the amp to a friend’s place and checking if the problem persists. Alternatively, you can also get an A/C line tester to check the grounding in your apartment. If this is the problem, have a technician come and double-check it and get it sorted ASAP as it can lead to electrocution.
Do guitar pickups cause radio interference?
Poorly wound coils in any guitar pickup can be the reason for background interference (especially if they’re set to a low height and cranked to make up for the drop in volume). In fact, pickups are made from magnet surrounded (wound) by wire coils. When you strike the guitar string, it vibrates in the magnetic field of the pickup and an alternating current is generated that is converted into an audio signal. Subsequently, the coiled magnets also act as an antenna, making it possible to pick up stray airwaves and radio frequencies.
None of that worked, now what?
There can be a multitude of reasons (though very rarely the case) that can be causing this situation besides the small list we shared earlier. If all else fails, it’s time to sift through the nitty-gritties and zero-in on the root cause.
Is faulty guitar shielding causing this issue? Do a thorough check of your guitar or take it to a technician. Guitar shielding can be done in one of two ways – 1) via conductive shielding paint (like graphite), or 2) using aluminum or copper tape (most common).
Most mass-produced guitars ship with conductive paint on the control pots and pickup cavities but there is no consensus if this is the most efficient way to shield the instrument. First, inspect the cavity under the guitar pickup and on the flip side under the bridge. If you have a multimeter (or can get one), check for stability from your ground to the bridge to ensure there is no problem there.
Did you try changing the direction that the guitar amplifier is facing? Did you try turning your guitar towards and away from the amp to check if it makes any difference? Did you try another amplifier or a bass running through the same amp to see if the problem persists?
If it only happens with ‘that one electric guitar’ or ‘that one cable’, that tells you right away that there may be a fault with the guitar shielding or a spot in the cable that exacerbates the problem. I recommend meticulous troubleshooting – strip the components or isolate the elements down to the bare minimum to pinpoint the source of the problem.
When all else fails, call the local expert.
If you are 100% sure you haven’t mistaken your radio for a guitar amp, then one of the many solutions we’ve mentioned should sort out the problem. However, if all your efforts fail and you still can’t get rid of the radio interference from your amplifier, I hope you are catching a good song that you can enjoy as you wait for a local electronic technician to come by and help you sort the problem.
Until the airwaves are sorted, you might as well enjoy whatever tunes the local airwaves throw at you. With any luck, that won’t be the case and I hope this article clears the air(waves) to help you resolve the issue.