How do I get the radio out of my amp?

[irishryno]

I have a Hartke HA 3000 and I receive a local radio station when I have the amp on. Is there a way to correct this?

[jordy_on_bass]

Does the local radio station pick up your bass lines??

I am pretty sure it has something to do with the pick ups, but am not 100% sure if this is correct, let alone what is causing it to do this.

Cheers,
Jordan

[Yango]

It's a shielding problem. If your amp picks up the radio station when your bass and cables are not plugged in, then the shielding problem is somewhere in your amp.

Usually, the problem is lack of shielding in the bass itself. Also, if you've got cheap cables, then the combination of the bass and cable act as a big antenna.

Open up your control cavity on your bass to see if there's any shielding paint or copper foil. If there's nothing in there, that's a good place to start. And if you paid $5.00 for your cable, there's probably no shielding in there at all... and it might be a good idea to get a decent cable.


this may help:
http://www.guitarnuts.com/wiring/shielding/bass.php

[VisualShock]

try using ballanced cables, also known as stereo or TRS jack cables

[PhiDeck]

Originally Posted by VisualShock

try using ballanced cables, also known as stereo or TRS jack cables

I'm obviously missing something... How does using a stereo cable between a bass and amplifier (that have mono jacks) help?

It would seem that there would be no electrical connection, at either end, to the ring terminal. Which means one of the two wires in the shielded (twisted?) pair would be electrically floating.

[BassmanPaul]

It won't! If you have an active bass it won't even switch on the pre-amp.

Paul

[BassmanPaul]

OP, does the amp pick up the station with nothing plugged into the input?

Paul

[Absentia]

This happens to me when I'm playing near the college.
Take a sheet of tinfoil and poke the cable through it before plugging it into the amp for the tinfoil acts as an extra ground against the chassy. Works like a charm ...sometimes.

[irishryno]

cables arnt the problem. im using monster. pick ups im not sure about. its a geddy lee edition fender. is there something i could do inside the amp case with out frying it

[BassmanPaul]

Originally Posted by irishryno

cables arnt the problem. im using monster. pick ups im not sure about. its a geddy lee edition fender. is there something i could do inside the amp case with out frying it

Monster cables are expensive and not necessarily good.

You could try answering the questions you are asked so the problem can be debugged!

Paul

[PhiDeck]

You need to isolate the problem before you can fix it. Methodical troubleshooting uses a process of elimination. Usually a binary search method converges on the location of the problem quicker than does a haphazard approach.

A radio interference problem requires:
- an antenna
- a demodulator

Except in radio receivers, neither is there intentionally. The existence of an unintentional demodulator is often caused by sub-optimal design that is beyond your control, and which may be irrelevant without an antenna. Hence it is best to focus first on finding the unintentional antenna.

Antennas are usually wires, cables, or printed circuit board traces, usually poorly shielded and/or poorly connected. Assuming that a cable is not the problem because of its brand name or its exorbitant price is no part of methodical troubleshooting.

[jazzblade]

Is it always there when guitar is plugged in? yes no?

cable but not guitar plugged in? yes no?

No cable or bass just amp on? yes no?


When did it start has it always been there?

If you move the amp around does it change anything,?

Look outside, IS THERE A 50,000,000 WATT ANTENNA NEXT TO YOUR HOUSE??

OH! is it plugged into a grounded outlet?? (just a thought IDK)

[Codger]

RF bead on the input lead just inside the input jack.

[Tommygunn]

Buy a new amp. I'd keep it that way, its kinda cool. I wish my guitar amp did that.

[fingertap]

Excellent troubleshooting advice, above.

How long is the cable from the head to the speaker cab(s)?

It may also be (rarely, though) that the cable from the head to the speakers is the culprit.
Certainly try changing this cable to a different and shorter one before you decide to open up the head!

~

[jazzblade]

I doubt seriously if we will hear back from the OP, Seems he doesn't acknowledge too often if he is helped in any of the other threads I have read.

[Growly Lytes]

We tried ???

[BassmanPaul]

Originally Posted by fingertap

How long is the cable from the head to the speaker cab(s)?

It may also be (rarely, though) that the cable from the head to the speakers is the culprit.
~

The impedances involved makes this a virtual impossibility. If it was a factor, speaker cables would be screened.

Paul

[fingertap]

Originally Posted by BassmanPaul

The impedances involved makes this a virtual impossibility. If it was a factor speaker cables would be screened.

Paul

I based my response on experience (I have had RFI from radio stations enter amplifiers through speaker cables, though rarely.) Information in support of this may be seen on page 456 of 'The Art Of Electronics' Horowitz & Hill, second edition,

Chapter 7, PRECISION CIRCUITS AND LOW-NOISE TECHNIQUES, section 7.23, Signals coupled through inputs, outputs, and power line

"...In devices like audio amplifiers you can use low-pass filters on inputs and outputs (much interference from nearby radio stations enters via the speaker wires, acting as antennas)...."

Italics are in the original. While not a reference book in particular, I have found it useful.


~

[crazy_bassist]

Are you using a wireless system by any chance?