Listening to the radio- Via a Tube boost pedal

SmokeyDopey · 08-01-2012, 11:17 AM

I bought a handmade Tube boost pedal (made by an amp tech here), and at moments it picks up the radio. It happened a couple of times only, I guess it depends where you are located. Not a big issue, but concerned that at some point it WILL become an issue, like in a recording situation.
We're recording at a studio this week and the next, and no radio has been picked up, I guess the studio may be well isolated, but I don't know. We're using it for the bass, though. We're putting it in the loop of my bassist's Ampeg SVT 400T to give it just a teeny bit of grit, and it adds a little harmonic content (Sounds pretty ****in good actually, I recommend it).
It has a 12AT7 tube in it, by the way.

My question... Is there a way to isolate this somehow? If for example I'm not at a studio, and it's picking up the radio.
Put it in a led box?
Dig a deep hole to put the pedal in?
Force field?

This is the pedal, by the way. Not my photo, mine is actually metallic color, and black knobs:

GIBSON67 · 08-01-2012, 11:51 AM

Cool little pedal, if it happens again I'd try switching the tube with another...hell, I'd try switching tubes anyway...try a 12ax7 in there, or a 5751. Sorry I wan't any help. M2C.

SmokeyDopey · 08-01-2012, 11:57 AM

Ha! the 1st thing I asked the guy when I was about to buy it was if I could swap tubes.

I was thinking of a 12AX7, but it may be a bit too much. With the current tube, I have the gain at about 11 O clock and it's enough (If it were marked 1-10, it would be somewhere around 3 and 4). And a 12AX7 being a higher gain tube, I ASSUMED the radio signal would be picked up even louder. Is this true?

It's an Electro Harmonix tube. But I have an extra 12AX7 laying around, I'll give it a shot.

pedecamp · 08-01-2012, 12:15 PM

I'd talk to the guy who built it. Maybe it needs shielding foil inside he forgot or something.

Micky · 08-01-2012, 12:20 PM

Chances are it is a problem only at your CURRENT location.
Most times this is a problem with a certain length cable and proximity to the transmitter.
Generally the offending component is a cable the EXACT length of a multiple of the radio station frequency (wavelength). You may be able to stop the effect simply by using a shorter cable.

In rare cases it is caused by an oscillator within the device that operates at an exact multiple of the station frequency (harmonic), and this can sometimes be easily adjusted OFF the frequency. We call it tuning out birdies...

StratoMarshall · 08-01-2012, 03:44 PM

Quote:

Originally Posted by Micky

We call it tuning out birdies...

AhHa...radio guy,eh?

GuitarBuilder · 08-01-2012, 06:00 PM

Quote:

Originally Posted by Micky

Chances are it is a problem only at your CURRENT location.
Most times this is a problem with a certain length cable and proximity to the transmitter.
Generally the offending component is a cable the EXACT length of a multiple of the radio station frequency (wavelength). You may be able to stop the effect simply by using a shorter cable.

In rare cases it is caused by an oscillator within the device that operates at an exact multiple of the station frequency (harmonic), and this can sometimes be easily adjusted OFF the frequency. We call it tuning out birdies...

+1

Changing tubes won't solve a thing. A higher quality guitar cable and good ground at the amp will work wonders.

brp · 08-01-2012, 06:09 PM

I was going to say something tells me that it isn't the pedal causing this issue.

SmokeyDopey · 08-01-2012, 06:30 PM

I have good cables.
The amp? I can't say much, it's a clone and I know nothing of electronics.

Another detail that may be important... I do have a of radio antenna close by my apartment.
BUUUT... My bassist tried it at his apatment, and said that for a little while he was picking up a radio also. But I'm not sure if he lives close by to one. Plus, he was using a different amp, different instrument, and different cables.
It has to be the pedal.

Quasar-Kid · 08-01-2012, 06:49 PM

Quote:

Originally Posted by pedecamp

I'd talk to the guy who built it. Maybe it needs shielding foil inside he forgot or something.

Aluminum foil internal wrap...
That'll solve the "Radio Wave" issues

brp · 08-01-2012, 06:49 PM

Hmm... How about trying a little DIY Faraday cage when it's getting the RFI and see if it goes away.

SmokeyDopey · 08-01-2012, 07:43 PM

Quote:

Originally Posted by brp

Hmm... How about trying a little DIY Faraday cage when it's getting the RFI and see if it goes away.

A ghetto force field?

That would be a fun experiment. I{ll have to make sure the signal is strong, put the gain all the way up, then put it in the cage

Micky · 08-01-2012, 07:49 PM

Sometimes a simple clamp-on RF choke on the offending cable will work wonders.
Try different length cables first though.

(yes, radio guy...)

SmokeyDopey · 08-01-2012, 07:52 PM

Quote:

Originally Posted by Quasar-Kid

Aluminum foil internal wrap...
That'll solve the "Radio Wave" issues

I already tried with an aluminum foil hat on.
Issue persists.

SmokeyDopey · 08-01-2012, 07:54 PM

Quote:

Originally Posted by Micky

Sometimes a simple clamp-on RF choke on the offending cable will work wonders.
Try different length cables first though.

(yes, radio guy...)

I didn't know what the HELL that is...
Reading about it as we speak. Thank you Micky.

Would that go on the guitar's cable, or the transformer cable going into the pedal?

Quasar-Kid · 08-01-2012, 07:58 PM

Quote:

Originally Posted by SmokeyDopey

I already tried with an aluminum foil hat on.
Issue persists.

So that means it's not simply transmitting/receiving radio waves that means its also Amplifying them...

Ugh...

SmokeyDopey · 08-01-2012, 08:03 PM

...Or I can just pin point what station it is, call them up, and tell the guy to shut the **** up for 2 seconds while I finish recording the guitar part.

Micky · 08-01-2012, 08:06 PM

Quote:

Originally Posted by SmokeyDopey

I didn't know what the HELL that is...
Reading about it as we speak. Thank you Micky.

Would that go on the guitar's cable, or the transformer cable going into the pedal?

I put them on all my cables.
They only cost a couple bucks each.
Sometimes you can take them off an old cable of sorts.
Or you can go down to Rat Shack and see if they have any.

SmokeyDopey · 08-01-2012, 08:10 PM

That's crazy about the guitar cable's length... Got me thinking. I never would've imagined.

I appreciate everyone's tips! I'll give them a shot and see what happens. I still need to take it back to the guy because the volume knob at moments acts weird... So I'll mention it to him as well.
It has a warranty, so no issues with that.

Thanks again guys.

LesPaulopolis · 08-02-2012, 04:02 PM

I have a similar issue with my entry-level Peavey bass. I chalk it up to a combo of the shitty PUPs / interior sheilding and bargain price cable. Happens in a lot of amps. Good luck.

08-01-2012, 11:17 AM	#1 (permalink)
SmokeyDopey Senior Member Join Date: Mar 2011 Location: Argentina Posts: 8,302	Listening to the radio- Via a Tube boost pedal I bought a handmade Tube boost pedal (made by an amp tech here), and at moments it picks up the radio. It happened a couple of times only, I guess it depends where you are located. Not a big issue, but concerned that at some point it WILL become an issue, like in a recording situation. We're recording at a studio this week and the next, and no radio has been picked up, I guess the studio may be well isolated, but I don't know. We're using it for the bass, though. We're putting it in the loop of my bassist's Ampeg SVT 400T to give it just a teeny bit of grit, and it adds a little harmonic content (Sounds pretty **in good actually, I recommend it). It has a 12AT7** tube in it, by the way. My question... Is there a way to isolate this somehow? If for example I'm not at a studio, and it's picking up the radio. Put it in a led box? Dig a deep hole to put the pedal in? Force field? This is the pedal, by the way. Not my photo, mine is actually metallic color, and black knobs:

08-01-2012, 11:51 AM	#2 (permalink)
GIBSON67 Senior Member Join Date: Sep 2008 Location: Lakeland, TN Posts: 3,303	Re: Listening to the radio- Via a Tube boost pedal Cool little pedal, if it happens again I'd try switching the tube with another...hell, I'd try switching tubes anyway...try a 12ax7 in there, or a 5751. Sorry I wan't any help. M2C.

08-01-2012, 11:57 AM	#3 (permalink)
SmokeyDopey Senior Member Join Date: Mar 2011 Location: Argentina Posts: 8,302	Re: Listening to the radio- Via a Tube boost pedal Ha! the 1st thing I asked the guy when I was about to buy it was if I could swap tubes. I was thinking of a 12AX7, but it may be a bit too much. With the current tube, I have the gain at about 11 O clock and it's enough (If it were marked 1-10, it would be somewhere around 3 and 4). And a 12AX7 being a higher gain tube, I ASSUMED the radio signal would be picked up even louder. Is this true? It's an Electro Harmonix tube. But I have an extra 12AX7 laying around, I'll give it a shot.

08-01-2012, 12:15 PM	#4 (permalink)
pedecamp Senior Member Join Date: Dec 2009 Posts: 2,405	Re: Listening to the radio- Via a Tube boost pedal I'd talk to the guy who built it. Maybe it needs shielding foil inside he forgot or something. Quasar-Kid likes this. __________________ DSL50

08-01-2012, 12:20 PM	#5 (permalink)
Micky Senior Member Join Date: Apr 2010 Location: Vermont Posts: 6,464	Re: Listening to the radio- Via a Tube boost pedal Chances are it is a problem only at your CURRENT location. Most times this is a problem with a certain length cable and proximity to the transmitter. Generally the offending component is a cable the EXACT length of a multiple of the radio station frequency (wavelength). You may be able to stop the effect simply by using a shorter cable. In rare cases it is caused by an oscillator within the device that operates at an exact multiple of the station frequency (harmonic), and this can sometimes be easily adjusted OFF the frequency. We call it tuning out birdies... diesect20022000, SmokeyDopey and GuitarBuilder like this. __________________ I can understand stupidity, but there is no excuse for ignorance... Marshall MHZ15, DSL40c, M4, 4X12 full stack, Gibson LP, VOX, Eminence, Celestion, Ovation, Fender & more...

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08-01-2012, 06:09 PM	#8 (permalink)
brp Senior Member Join Date: Nov 2010 Location: Vancouver, Canada Posts: 4,074	Re: Listening to the radio- Via a Tube boost pedal I was going to say something tells me that it isn't the pedal causing this issue. __________________ Recommended: On Floor Audio mods by HOT TUBES 70, Martimus Maximus tubes from MartyStrat54, NOS tubes from RiverRatt -- My Studio -- "If we can't laugh at the dead, we have no business killing people"

08-01-2012, 06:30 PM	#9 (permalink)
SmokeyDopey Senior Member Join Date: Mar 2011 Location: Argentina Posts: 8,302	Re: Listening to the radio- Via a Tube boost pedal I have good cables. The amp? I can't say much, it's a clone and I know nothing of electronics. Another detail that may be important... I do have a of radio antenna close by my apartment. BUUUT... My bassist tried it at *his* apatment, and said that for a little while he was picking up a radio also. But I'm not sure if he lives close by to one. Plus, he was using a different amp, different instrument, and different cables. It has to be the pedal.

08-01-2012, 06:49 PM	#11 (permalink)
brp Senior Member Join Date: Nov 2010 Location: Vancouver, Canada Posts: 4,074	Re: Listening to the radio- Via a Tube boost pedal Hmm... How about trying a little DIY Faraday cage when it's getting the RFI and see if it goes away. __________________ Recommended: On Floor Audio mods by HOT TUBES 70, Martimus Maximus tubes from MartyStrat54, NOS tubes from RiverRatt -- My Studio -- "If we can't laugh at the dead, we have no business killing people"

08-01-2012, 07:49 PM	#13 (permalink)
Micky Senior Member Join Date: Apr 2010 Location: Vermont Posts: 6,464	Re: Listening to the radio- Via a Tube boost pedal Sometimes a simple clamp-on RF choke on the offending cable will work wonders. Try different length cables first though. (yes, radio guy...) SmokeyDopey likes this. __________________ I can understand stupidity, but there is no excuse for ignorance... Marshall MHZ15, DSL40c, M4, 4X12 full stack, Gibson LP, VOX, Eminence, Celestion, Ovation, Fender & more...

08-01-2012, 08:03 PM	#17 (permalink)
SmokeyDopey Senior Member Join Date: Mar 2011 Location: Argentina Posts: 8,302	Re: Listening to the radio- Via a Tube boost pedal ...Or I can just pin point what station it is, call them up, and tell the guy to shut the **** up for 2 seconds while I finish recording the guitar part. Quasar-Kid likes this.

08-01-2012, 08:10 PM	#19 (permalink)
SmokeyDopey Senior Member Join Date: Mar 2011 Location: Argentina Posts: 8,302	Re: Listening to the radio- Via a Tube boost pedal That's crazy about the guitar cable's length... Got me thinking. I never would've imagined. I appreciate everyone's tips! I'll give them a shot and see what happens. I still need to take it back to the guy because the volume knob at moments acts weird... So I'll mention it to him as well. It has a warranty, so no issues with that. Thanks again guys.

08-02-2012, 04:02 PM	#20 (permalink)
LesPaulopolis Senior Member Join Date: Jan 2009 Location: Minneapolis Posts: 1,903	Re: Listening to the radio- Via a Tube boost pedal I have a similar issue with my entry-level Peavey bass. I chalk it up to a combo of the shitty PUPs / interior sheilding and bargain price cable. Happens in a lot of amps. Good luck. __________________ '68 RI LP Custom '93 Anniversary 6100 (6L6s) '90 JCM900 4100 (EL-34s) Epi. Valve Jr. head (Gain & Bright mod) In Front: MXR Custom Modified OD > Voodoo Labs Sparkle Drive In Parallel Loop: TU-2 > Flashback Delay > MXR Carbon Copy

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