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Your Not Going To Believe This

Posted: 26 May 2001 7:43 am
by Andy Alford
I have a tube amp that I will keep the brand a secret.It picks up radio stations at night while I am playing.What can be done to correct this problem?

Posted: 26 May 2001 7:53 am
by Blake Hawkins
Move away from Red Mountain.

Posted: 26 May 2001 7:55 am
by Jim Cohen
Smoothly modulate into the same key as the radio.

Posted: 26 May 2001 8:01 am
by Bobby Lee
Use longer or shorter wires.

Posted: 26 May 2001 8:25 am
by Andy Alford
I contacted the shortwave station by email and they did not reply back.My frind has the same type of amp but he is geting a local rock rap station.Our amps are used by many players on the forum.

Posted: 26 May 2001 10:13 am
by Brett Cookingham
As far as I can remember speaker cable is more likely to pick up radio because it is not shielded. Try changing the position of the amp or changing speaker cable. Don't use a sheilded cable on your speaker 'cause you can fry your amp!

Posted: 26 May 2001 10:59 am
by Donny Hinson
Play it in the daytime...that'll be $10 please.

(Sorry, I couldn't resist...I a Groucho fan!)

Seriously, though...does it do it when nothing's plugged into it? If it does, then the problem's in the amp. If it does it only when the guitar is plugged into it, then the RF is coming in that way.

If it's an amp problem, then a tech can put an RF choke on the preamp end, and probably eliminate it. If it's coming in through your cables, you might try just changing the lengths of them, or try different cables.

Tell us also if you are using any other "devices" between the guitar and the amp.

Posted: 26 May 2001 11:19 am
by Jack Stoner
Spring reverb units will do this sometime. But check the cables to/from the reverb and make sure the shields are in good condition and grounded.

There are a lot of potential points in a tube amp that could be the problem. I've seen bad preamp tubes cause that too.

Posted: 26 May 2001 1:12 pm
by Dave Seddon
I think Jack is probably right, I have the same problem when I play at Rugby in England,(masses of raio relay aerials) I get loads of Italian stations coming through my Peavey amp, yet when I use the VOX AC30 which doesn't have a spring reverb, no problem whatsoever. I think you have got reverb transducer problems.
All the best
Dave.

Posted: 26 May 2001 3:31 pm
by Rick Aiello
Used to happen when I lived in Miami. I would pick up Cuban stations - steel and salsa???? Only happened with tube amps - especially my Fender Pro Junior (NO REVERB). The more gain - the louder the station (with or without steel hooked up). I tried RF chokes - even built an RF filtering chamber (amp encased in a grounded wire cage - an electrical engineer built for me). Nothin' worked so I had to resort to my Peavy for recording. Now I live in a cabin in the Blue Ridge - no more salsa - just some Scruggs wantabe livin' down in the "holler".

Posted: 26 May 2001 5:36 pm
by Keith Hilton
Try a 39pf capacitor to ground on the input. Most people who build electronics for the music industry put in protection for RF signals. Why doesn't this rig have them?<FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by Keith Hilton on 26 May 2001 at 06:37 PM.]</p></FONT>

Posted: 26 May 2001 6:04 pm
by patrick donovan
my Fender vibroverb doubles as a 6 meter reciever on some nights, so I use the Nashville 400. Changing cable/amp positions helps to some degree.


Regards, Patrick
KD5DNV

Posted: 26 May 2001 6:31 pm
by Andy Alford
When I move the amp to another room I get another radio station.I must say that my amp does receive some great programs from Canada.The amp is a very well made amp that many people use.It has a great sound but I did not know that the radio was part of the deal.I will try some of your ideas.Thanks alot

Posted: 26 May 2001 6:51 pm
by jerry wallace
Andy, back in the 1970's when CB radios were the "hot thing"..If some one drove near by the club I was playing while transmitting,It came threw my Amp..Since they were moving, it unually only lasted a few seconds until they were to far away..
I am a "ham radio" operator so I know a little about RF signals..I have seen the same thing come through Stereo and TV audio..
Its also possible the RF is getting into the speaker wire leads..Try wrapping some tin foil around the speaker wires{leads} and make sure it is grounded to the metal chassis somewhere..You can use a alligator clip masking tape or something to do this..If its coming in to these wires this should stop it..
Having worked with high amounts of RF wattage, If the wattage of the signal is strong and close enough..You may not be able to get rid of it..The frequency of the transmitter can also have an effect..Some stations operate with 50,000 watts of Radio Frequency AC signals..Man would that make a great amp!! Image Image WD5ADE

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Jerry Wallace- "98 Zum: D-10,8+8, "96 Zum: D-10,8+5,Nashville 1000,Session 500 ,Tubefex,ProfexII, Artesia, New Mexico

<FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by jerry wallace on 26 May 2001 at 07:56 PM.]</p></FONT><FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by jerry wallace on 30 May 2001 at 07:36 AM.]</p></FONT>

Posted: 27 May 2001 6:24 am
by Dennis Detweiler
Lean over your guitar and curse into your pickup. Don't press the B pedal!
Dennis

Posted: 27 May 2001 3:11 pm
by Rich Paton
Andy, try asking your question here:
http://www.firebottle.com/ampage/
Choose discussion forums, guitar amps.
Good Luck!

Posted: 27 May 2001 6:11 pm
by Paul Graupp
One morning between 6 and 7AM we were live on the air from Channel 5 in Raleigh, NC. In the middle of a song, my Fender Twin blasted
out with; "Hey there Good Buddy. What's your
10-20 ?" It never did it again and we think there must have been a trucker with a CB Kicker on his rig that was passing by. I'd say it was in the reverb springs because the level was very high and obviously amplified which may not have been the case were it the speaker wires. We caught H- - - from the audio man but I also worked there as an engineer so I got off OK. At least he didn't use real trucker language ! Regards Paul Image Image

Posted: 30 May 2001 6:22 am
by John Sims
Don't forget chokes or ferrite cores/bars on the power cord leads. I have some if any body needs them I also have clamp on ferrite chokes/doughnuts. E-mail me...

KA4ZAY

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Regards,

John

Steelin' is a way of life!

My PSG website-Carter SD-12-U, 8p/5k, Nashville 1000


Posted: 30 May 2001 6:24 am
by John Sims
BTW...Free. First Come First Served.

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Regards,

John

Steelin' is a way of life!

My PSG website-Carter SD-12-U, 8p/5k, Nashville 1000


Posted: 31 May 2001 8:14 am
by Jim Peter
I had this same problem with my Mesa/Boogie 50/50 power amp. After talking to the guys at Boogie they convinced my to replace the (3) pre-amp tubes in the power amp which took care of the problem.

Jim

Posted: 1 Jun 2001 1:50 am
by Chip Fossa
I used to practice in the early years with
headphones monkey-rigged to a turntable.

One cold winter's day, while I was merrily
playing along, a fuel oil delivery truck was
in my area making his rounds.

The reason why I know this, is that he pretty near blew me out of my seat as he
talked back and forth, on his short-wave, to his company's command center. I mean, not only did he
come in, he came in LOUD & CLEAR. It scared the hell out of me.
FWIW

Posted: 8 Jun 2001 4:58 pm
by Derrell Stephens
A 39 to 56pf cap between signal input and ground is the 1st thing to try if the amp still has radio signals blasting through with nothing plugged into the amp inputs. The 2nd option is a 39 to 56pf cap in the reverb "in" line due to the high gain characteristics of the circuity. If you have tubes to change out and it is easy for u to do this, thry that 1st; usually the preamp, high gain tubes 1st. This has worked for me in the past many times.
I hope this helps and good luck.

Posted: 1 Jul 2001 10:28 pm
by David Stehman
Andy, I 2nd what the ham guys above John and Jerry said about chokes and caps. Us hams are used to signals getting into and outof
where they shouldn't, whether it's our equipment or others', so we're used to dealing with it. It's like playing with others-sometimes we're resonant with others beat and frequency, sometimes we're not. Any part of am amp from power cord to speakers or from guitar cord or pickups can resonante
with what it hears. Dave N4DAG

Posted: 2 Jul 2001 11:06 am
by John Steele
I used to work in this particular bar, and everyone's amp used to bring in taxicab radios there. It seemed to have more to do with the building and it's wiring than the amp. It made for some strange moments on stage !
-John

Posted: 2 Jul 2001 9:24 pm
by gary darr
I used to play in this little place in Dallas, it used to be a drive in beer and burger joint. any way we played inside and the sound was allso run outside for the drive-up patrions. There was this one particular individual who though it was funny to park right behind the band stand and talk on his C B radio and disrupt the music. The lead guitar player had allready had asked him several times to quit,the guy still continued so the lead player quietly put his guitar down, walked up the the vehicle broke the C B antenea off at the base,I think the guy finally got the message,end of problem , we finished out the night without so much as a peep. I guess you just had to be there.

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sho-bud,session 500,american standard strat,shecter tele,peavy classic 50