T.R | Title | User | Personal Name | Date | Lines |
---|
2235.1 | | STRATA::KLO | | Tue Jun 18 1991 10:57 | 8 |
| My distrotion pick up all time if you used your amp high volum.
used your amp to listen to the news.....sometime.
|
2235.2 | I Was Tuned In Just Last Night Myself | RGB::ROST | I believe she's a dope fiend | Tue Jun 18 1991 11:07 | 8 |
| When you get the gain up high enough (either with the amp's own preamp
or through a fuzz box, etc.) and if you're not shielded well enough,
you are picking up AM radio transmissions which need only to be
rectified to be audible. As you move around the room, adjust your
volume and tone knobs, etc. you effectively retune the frequency of the
antenna. It's pretty darn common.
Brian
|
2235.3 | If you reverse it, can you broadcast? | ZEKE::MEMBRINO | four > six | Tue Jun 18 1991 11:27 | 12 |
| re:.0
Yeah, It can certainly add a lot to a solo! 8^)
My band rehearses in a 25' by 20' room and this happens all the time
(to our guitarists). It can cause trouble when you are recording if
you are mic-ing the amps.
(Plus it's pretty weird hearing it thru the headphones when you don't
expect it!)
chUck
|
2235.4 | | RAVEN1::BLAIR | Need a hot tune and a cold one | Tue Jun 18 1991 11:31 | 5 |
|
Yup, pretty darn common. I get less antennuation(?) since I
shielded the strat cavity though. Another weird noise I pick up
is when I am standing near my cd player. When I hit close/play,
I pick up alien transmissions before the song begins.
|
2235.5 | I hear you! | EZ2GET::STEWART | No, I mean Real Music. | Tue Jun 18 1991 12:14 | 11 |
|
Yeah, this unwanted receptions are common in all kinds of audio gear.
Another source of noise (as suggested by mention of the cd player) is
any TV, VCR, or digital gear. I had to move my MT32 away from my
Quattro 'cause the preamp was picking up the noise radiating from the
MT32's digital circuitry. Before I replaced the cheap pickups in my
Squire II bass, I could pick up the flashing clock display on my VCR.
And then you have to watch out for the noise caused by light dimmers...
|
2235.6 | | LEDS::BURATI | Spanish Castle Magic | Tue Jun 18 1991 12:20 | 10 |
| I think this is RFI getting into your low level signal path and
subsequently being decoded by a circuit acting as a simplt diode
detector, the most rudimentary form of a radio receiver. I've been using
a strat with no extra shielding and no metal plate under the PG fo
twenty years and I don't think I've have ever experienced this without
some effect box between the guitar and the amp's input.
Of course, I don't live on top of a 50KW radio transmitter, either. But
check out your cabling and connectors. Connectors with metal covers are
superior to those with plastic for this reason.
|
2235.7 | | HYEND::C_DENOPOULOS | YouGotTheRightOneBabyAhaAha! | Tue Jun 18 1991 12:50 | 7 |
| My Kustom used to pick up radio stations all the time. A flick of the
ground switch would usually take care of it.
The scanner I used to have would pick up Russia's TASS news service,
rebroadcast out of New York.
Chris D.
|
2235.8 | | ESKIMO::AUSTIN | | Tue Jun 18 1991 13:23 | 10 |
| Well waddya know, my amp isn't possessed after all. It was pretty
freaky the first time I heard it, like Jimi Hendrix or Brian Jones
were trying to make contact.
It's only happens when I use my CryBaby and heavy distortion. I think
I'll look over the innards of my Kramer tonight and check for broken
shields or shakey grounds.
Thanks for satisfying my curiousity,
Alan
|
2235.9 | wah-wah plus fuzz, yep, that'll do it | LEDS::BURATI | Spanish Castle Magic | Tue Jun 18 1991 13:58 | 8 |
|
Hey, for all I know Jimi Hendrix or Brian Jones could be trying to make
contact. :|
But now that you mention it, it seems that my old VOX wah-wah was
usually involved in the signal chain.
|
2235.10 | | RAVEN1::BLAIR | Need a hot tune and a cold one | Tue Jun 18 1991 14:09 | 13 |
|
In the words on Dennis Miller (SNL) -
"If Brian Jones were alive today..."
"we'd all be a little surprised."
8^)
|
2235.11 | Bad connections | ELWOOD::HERTZBERG | History: Love it or leave it! | Tue Jun 18 1991 17:28 | 4 |
| Yup. .6 showed the direction. This is quite often caused by a poor
connection, which can look electrically like a network which contains a
diode. Look for bad connections.
|
2235.12 | "What's THAT??!?" | GOES11::G_HOUSE | Carpe diem | Tue Jun 18 1991 19:12 | 6 |
| I used to pick up police radio signals when I had my rack rig. Kind of
disconcerting at first, but we always knew when they were coming to
shut down our practices, as it only seemed to happen when there was a
police car nearby or an officer with a hand held radio.
Greg
|
2235.13 | | PAKORA::IGOLDIE | | Tue Jun 18 1991 22:34 | 2 |
| My amp picks up the signal from passing taxis and my amp previous to
that picked up some foreign radio station.
|
2235.14 | Come in London | MILKWY::JACQUES | Vintage taste, reissue budget | Wed Jun 19 1991 00:52 | 25 |
|
I've seen this happen many times over the years. It's not
only limited to AM radio either. I used to play in a guys cellar,
and a couple of neighborhood kids used to spend the evening talking
into a CB radio they had under the dash in their car. We used to
pick up the CB signals they were sending plain as day.
The lead player in my current band plays through a Vox AC30
and he picks up radio transmissions all the time. This amp also
picks up noise from various lights in the house (some are simple
incondescient lights). We have reason to believe this amp is
picking up short wave, as many of the signals we pick up seem to
come from Europe (what the heck, it's a British amp, isn't it?).
At any rate, everything you plug into your amp is essentially
an antenna. The longer your' cord, the greater antenna gain you will
have. Humbuckers are not a big problem since the two coils tend to
cancel out RFI (radio frequency interference). Having a stomp box
between the guitar and amp that provides gain effectively acts like
an active antenna, and will boost weak radio signals to a high
enough level that your amp will amplify them.
Mark
|
2235.15 | Divine messages | BAHTAT::CARR | Dave Carr 845-2317 | Wed Jun 19 1991 10:20 | 3 |
| One day many years ago here in Yorkshire I was playing my guitar
using unscreened leads and I picked up Vatican Radio loud & clear.
*DC
|
2235.16 | AC30 receiver | GOES11::G_HOUSE | Carpe diem | Wed Jun 19 1991 12:45 | 11 |
| re: .-1
It was a message from God... ;^)
re: .-2
A Vox AC30 huh? That's interesting, I played an AC30 in a store
several years back that also picked up radio signals. Do they all do
this?
Greg
|
2235.17 | Spine-O-Tap... | GIAMEM::DERRICO | Stand and deliver! | Wed Jun 19 1991 12:48 | 11 |
|
Aaah...Good ol' Spinal Tap revisited....
I think in some cases you can install ferrite beads in certain place(s)
in your amps that can help. I am not shure where though. RF can come in
anywhere that's insufficiently shielded(as mentioned before).
I think I recall somewhere in a notes file something on this.
Probably in the Electro_hobbyist notes file.
|
2235.18 | another thought | LEDS::BURATI | Spanish Castle Magic | Wed Jun 19 1991 13:20 | 8 |
|
Ground loops can cause all sorts of problems. Maybe the AC30 has a
ground loop in its design. Or maybe VOX had a poor way of making ground
connections inside the chassis. Resistance in a ground connection is...
T R O U B L E
--ron
|
2235.19 | Many moons ago... Kinda related to the discussion at hand...
| KDX200::COOPER | Opinionated MIDI Rack Puke | Wed Jun 19 1991 14:01 | 13 |
| I was in a band that used to practice in the bassists basement. The guy had
money, and had some nice things - one of which was a wireless phone. The other
guitarist has just purchased a new wireless unit and we were practicing our
collective butts off one night. Between songs you could hear a voice thru
the guitarists rigs. We thought it was pretty funny until the bassist sez
"Hey, thats my wifes voice !" We turned up the amp a bit and sure enough,
it was the bassists wife...
...Talking dirty to her lover. Needless to say, practice was over. She was
out on her butt by the next day. :) Poor guy. You should've seen the look
on his face, and some of the expletives he used scared me (US Navy vet...) !!
jc
|
2235.20 | Receiving radio signals on music equipment | SOLVIT::KERR | | Tue Jan 07 1992 08:11 | 22 |
| I've got a good one here and was wondering if someone can give me a
hint (or just tell me that I'm nuts). Last night, since I had the
house to myself, I decided to bring my small practice amp and guitar
upstairs to practice in the living room, rather than staying down in
the cold, damp basement. After warming up, I began hearing voices,
and they were coming from my amp (which is solid state, if that helps).
At some points I could actually make out what was being said, and it
appeared to be a radio broadcast from some place with very pronounced
southern accents. But the signal kept going in and out, so I could
never get any call letters or other identifier (there was also a lot of
interference as well).
So, has anyone else ever experienced this? Was it in fact a radio
transmission, or are aliens from a distant world trying to tell me to
knock off the pitiful guitar playing? And, the big question, does
anyone know how to stop these unwanted backup singers?
Thanks,
Al
|
2235.21 | | PELKEY::PELKEY | Snert ! Fetch me my dagger. | Tue Jan 07 1992 08:41 | 7 |
| Your not alone,
Happens to me too.
I've not a clue how to avoid it,, nothing I've ever done has
stopped the 'voices' once they start.....
|
2235.22 | The Ghost in the Machine Nightmare | CARTUN::CARTUN::BDONOVAN | Floyd Snead's drum tech | Tue Jan 07 1992 09:07 | 19 |
|
Several years ago, at a job, no less, a beautiful music station
cut in through the bass player's rig. And, believe me, it didn't
fade in and out, it came in a full strength!
He had a three hundred watt plus set up with two 15" spkrs. in one
cabinet, and another 15 in huge folded horn enclosure.
It was so loud and pronounced, we actually had to stop in the middle
of a song. Nothing we tried would get rid of it. Eventually, the
bass player wound up playing through the keyboard player's amp,
essentially crippling our overall sound.
The audience thought it was hilarious! In retropsect, it reminds me
of the line from Spinal Tap about it "not being very fun to be
part of the comedy."
Brian
|
2235.23 | | FREEBE::REAUME | KH/REXX SnoB | Tue Jan 07 1992 09:11 | 9 |
|
Gee - you guys must be using the non-FCC compliant amps. B-}.
With all the wiring I've got in my rigs it's amazing that I don't
pick up stray radio frequency. I have seen it happen to others though
and it's usually not a desirable station that they are picking up!
-B()()M-
|
2235.24 | | MANTHN::EDD | I been shattered (shay-oo-bee) | Tue Jan 07 1992 09:15 | 8 |
| My father is a ham radio operator. Back when I lived with my parents
it wasn't unusual to hear him coming out over the bass amp or PA,
sometimes with amusing results...
"...'scuse me, while I kiss the sky!"
("ah, 10-4, over and out....")
Edd
|
2235.25 | REALLY annoying!!! | GOES11::G_HOUSE | Tommy The Cat | Tue Jan 07 1992 12:05 | 17 |
| This happened to me just a couple of days ago! I switched to a shorter
guitar cord and the problem went away. The first cord I was using was
an 18 footer and I switched to an 8 foot one and no more radio. Later
that night I started using another amp and used the 18 foot cord again
without any problems. FWIW the amps in question were a Marshall JCM800
(which got the radio noise with the long cord) and a JCM900 (which was
quiet with either cord).
Used to happen to me a lot when I had my rack rig. Seemed to only get
the police band though, so we always knew when the cops were coming to
shut us down, because I didn't get it until they were right outside...
I loved that scene in Spinal Tap where Nigel gets the radio signals
through his amp while they're playing at the Air Force Officers Ball...
;^)
Greg
|
2235.26 | happens to the best of 'em | MR4DEC::GREEN | | Tue Jan 07 1992 20:39 | 5 |
|
Jimi Hendrix got radio signals on his amp at the Isle of Wight concert.
It's on the album even : comes through loud and clear on the quiet
sections of the music. Imagine what it sounded like at the concert...
|
2235.27 | that's how it always begins....the voices.... | NAVY5::SDANDREA | plonkers 'r' us | Wed Jan 08 1992 09:36 | 11 |
| Sooooooo,
now you guys are hearing voices.....hmmmmm, tell me, do these voices
tell you to do terrible things? I strongly suggest a reduction in the
intake of recreatinal substances, or a little psycho-analysis/therapy
before there is yet another string of serial killings!!
8^)
Steve (who agrees with "the longer the cord, the better the reception
of yer fav radio station" theory)
|
2235.28 | No, it's not a prelude to a UFO invasion | TUNER::BROWN | No Dukes, No Kooks, No Space Cadets | Wed Jan 08 1992 12:09 | 13 |
| What you are seeing (and hearing) is a phenomenon called "audio
rectification" which means that an RF signal, usually AM, can be
detected and amplified by an audio amplifier. Usually happens with
local AM broadcast or nearby CB'ers, but it can also occur with
cordless phones, police and ham radios, and even shortwave broadcasts.
I remember hearing a story about a guy in a band who was practicing in
the garage or cellar, and heard a voice over his amp during the quiet
breaks. Turned out it was his SO talking with her affair-mate.
I had an unusual incident when using my phaser/flanger when it was
receiving Radio Moscow very clearly. Turned out to be a slightly
corroded input jack. Cleaned it and the cord plug and the Russians
went away.
|
2235.30 | Voices in the sky | SOLVIT::KERR | | Wed Jan 08 1992 13:43 | 6 |
| Thanks for all of the comments, war stories, and hints, I'll look up
note 2235. At least now I know I'm not crazy (well, I wouldn't go that
far). By the way, the voices said "buy DEC stock".
Thanks,
Al
|
2235.31 | I wasn't listening.... | NAVY5::SDANDREA | plonkers 'r' us | Wed Jan 08 1992 16:05 | 10 |
| re: -1
Al,
>> By the way, the voices said "buy DEC stock".
oh no! I just sold!
|)
Steve
|