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December 2002
Posts: 13
Location: Pittsburgh, PA | Hello all,
I bought a CK057 last Friday. I'm not sure exactly when it was manufactured (it and its serial number are at home), but it has the "old" (black) electronics controls, not the new OP-20 as pictured on the Ovation web site.
When I plug it in, I can listen to FM96.1 on it. It comes in clearly enough to sing along with the songs (apparently it's a top 40 station :( ). This interference seems to be coming from the guitar itself, not from the cord. (I'm using a pretty high-quality cord that's only about 4-5 feet long, so I'd be surprised if it were the cord anyway.)
I'm going to (when I get home) try replacing the 9V battery, and switching patch cords (just for grins). Anything else I should try, short of selling my house and moving? |
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December 2001
Posts: 7247
Location: The Great Pacific Northwest | You might call the Radio Station and find out where their transmitter (antenna) is located. It would have to be pretty close to get a consistant signal like that. Also, they may want to know about it, as from their end, it may be an indication of their power amp getting ready to fail. You may get a thank you if you can talk to the engineer. Also, try to use the tone of "hey, this is pretty cool, I can hear you on my guitar" If they think it's a complaint you'll just get the PR department with the "we conform to all FCC standards" line. |
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December 2002
Posts: 13
Location: Pittsburgh, PA | Thanks.
As it turns out, the station's transmitter (looked up on the FCC web site, complete with map) is about 3/4 mile due north of my house, broadcasting 44kW. :(
Unfortunately, the station is owned by Clear Channel Communications, which means I have about as much chance of actually talking with anyone there as I have of getting an audience with the Pope (and I'm not Catholic).
I don't seem to get this interference on anything else in my house. Would it be possible to improve the shielding on the electronics inside the guitar without ruining the sound?
Anyway, I bought a new 9V battery and a Monster cable (supposed to have some special magic wonder-shielding, ha) at lunchtime today, so I'll see if those help, but I'm fairly discouraged. |
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Posts: 7247
Location: The Great Pacific Northwest | If you had a "little" interference, if you stood a certain way, or if the weather was just right, then it might be a fault on your end. But a "clear signal" in a harmonic of the freq they are not supposed to be on... that could be a serious equipment problem on their end that they most likely would want to know about.
Before trying to modify your guitar, it's worth a phone call. Also, if the sturcture of your house isn't enough to stop the signal (or at least make it very weak) then I'm guessing a little aluminum is not going to help either.
Also, are you absolutly sure it's the guitar? Have you plugged other things into the amp you are using? WHat type of AMP are you using?
You'd be surprised how important you may become if you save them 1000's of dollars in FCC fines and lawsuits. The biggest problem is getting to someone that understands what you are saying. If indeed it is only 3/4th mile, I would hike over and there should be an Emergency Contact Information number posted on the gate. We are no longer in the days of the early 80's when transmitters bled through everything in the house. My guess is that it is more likely on their end, blown or leaky filter, faulty transformer etc.. |
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December 2002
Posts: 13
Location: Connecticut | The radio station antenna may be close enough to power lines to have the signal induced onto them. The transmitter at the radio station may in fact be overdriven this would assist in the signal induction onto the power lines. You can try plugging your amp into a different area of the house and see what happens. If it continues it is most likely the problem. If it stops grounging in the house is contributing to the problem. Either way you should contact the radion station. If you have a UPS for a computer with a spare outlet this should shunt the noise out a well.
Good Luck |
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Posts: 5750
Location: Scotland | Try some other guitars, amps & cables in the same location, if it happens with all of them you may well have a case. |
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December 2002
Posts: 13
Location: Pittsburgh, PA | So, this is partially solved.
It turns out it's my *strings* :eek: that are picking up the station.
I tried using a ferrite-bead RF choke on the guitar cord. I tried plugging the guitar directly into my home stereo receiver (in case it was a weird impedance issue with my POD). I tried changing the battery in the guitar's electronics. All still had interference. This is definitely something in or on the guitar (as I suspected all along, since *nothing* else in our house has ever picked up 96.1FM before -- and won't ever again, as soon as I get this solved).
I took the strings off, to try to put a ferrite bead on the wire bundle inside the guitar. I plugged it in, so I could hear when the noise went away as I placed the bead. No noise. None. Zip. Nada. Zilch. Bupkus. I cranked the gain all the way up, all the way through the signal path. No interference, just nice clean [emulated] tube hiss. The pickups are still working: I can clearly hear myself knocking on the body through the amp. So I put new strings on, and Eminem is back (yuck; doesn't this station ever play anyone else?).
Quick in-my-head calculation is that my strings are a pretty good approximation to six 1/4-wave antennas for a 96MHz FM signal. (Good enough for 44 kW at around 1000 yards, anyway.) I'm a bit baffled as to how I am hearing *this* through the electronics, though, since it's a piezo pickup and not a magnetic pickup like on a "conventional" electric.
Tomorrow I'll try grounding the strings to the 1/4" jack lug to see if it helps. |
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Posts: 3
| Djehuti,
What links do I need to follow on the FCC website to find the location and maps for the local antennae sites?
Thanks,
Jim |
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Posts: 13
Location: Pittsburgh, PA | Jim,
On the main page ( www.fcc.gov ), click "Media" under the "Bureaus & Offices" sidebar on the right, then "Audio Division" on the left, under "MB Divisions", then there is a section called "Internet Queries" that has links to searches you can do on FM/AM/TV/etc stations. ( direct link )
I used "FM Query", entered the station call sign, and chose the detailed output option which gave me everything I needed to know, including links to neighborhood maps showing the transmitter locations. |
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Posts: 6202
Location: Phoenix AZ | Sounds like you need to buy yourself a "longneck" ovation to avoid the problem (ha ha). |
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December 2002
Posts: 13
Location: Connecticut | Just wondering How do you like the CK057? The one I ordered should be delivered on Monday. How is the sound?? Other than the color was there any other noticable differences between the CC057 and it? I couldn't find any specs on the OP-20.
Thanks |
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December 2002
Posts: 3
| Djehuti,
Thanks for the FCC info. I have a similar problem as yours except it is with an amplifier. A couple times a year I get a radio station coming out of my amplifier. Next time it happens I'll have to listen long enough to find out what station it is and then look it up on FCC.gov.
Jim |
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December 2002
Posts: 13
Location: Pittsburgh, PA | Redsox1924,
I like the CK057 pretty well (except for the noise). This is, however, only my second guitar (the first being a Takamine Jasmine S35), and I'm not much of a player, so my opinion isn't a very informed one.
I played only a CC057 and a CK057 when I bought the CK057. The only difference my brain could tell between the two guitars was the color (the CC057 I played was black; my CK057 is purple). But my fingers and ears liked the CK057 a little better. Maybe the store just had newer strings on the CK057 that day.
My CK057 does NOT have the OP-20 preamp in it, as far as I can tell. On the CK057 page on the Ovation site, the picture of the OP-20 shows it as being a silver tear-drop-shaped module like the other OP series in the other guitars. But if you look closely at the enlarged image of the guitar itself on that page, you can see a square black preamp and separate battery compartment on the left side of the guitar. This is what mine has (in fact, my guitar is pretty much identical to the one pictured on that page).
Hopefully, if you get a CK057 that has an OP-20 in it, it will have better resistance to RF than mine. :rolleyes:
(Mr. Ovation, I agree that there could be something wrong with the transmitter and not my preamp. But I'm not having this interference on any other piece of equipment in my house, including other preamps in my studio, radio equipment, etc., so it's pretty hard for me to conclude that anything is at fault other than the preamp. If I complain to the station or the FCC, I'm sure they will reach the same conclusion.) |
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Posts: 7247
Location: The Great Pacific Northwest | Let us know what you find out and if you get it resolved. Audio and RF are two very strange beasts... |
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December 2002
Posts: 13
Location: Pittsburgh, PA | By the way, I exchanged some email with the engineer at our local NPR station (not the interfering station in my case, but I've interacted with him before and thought he might either have some insights or know the engineer at the interfering station), and it turns out he's a guitarist and has also had shield/ground trouble with Ovation preamps. :(
I tried grounding the strings and it didn't help. My next area of attack will be to try to improve the shielding of the internal electronics (maybe try again with an internal RF choke, or maybe put a shield around the wiring bundle).
Since I'm not in the middle of a recording project or anything requiring electric right now (mostly what I need to do is practice practice practice), I'm going to wait until Monday when Ovation's offices reopen and try to get more suggestions and advice from Ovation customer service. Unfortunately, my local authorized Ovation service center is the store where I bought the guitar, and it doesn't pick up the station there, so if I take it there for them to look at, they won't see the problem. |
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January 2003
Posts: 2
| Djehuti,
I am also about to purchase the CK057 (Dark Blue Pearl color). I saw a demo model at a local dealer in Boston, and it also had the older preamp (DJ-4, as it was described in the 2001 model catalog).
I too was under the impression that the 2002 CK057 was supposed to have the nicer OP20 preamp (with built-in chromatic tuner!), but not sure why it wasn't in the display model. The Ovation website does say that all the Celebritys should have the newer electronics.
Is it possible that the one I saw at the dealer was a 2001 model? I got the serial number (2102230), but haven't been able to find any serial number charts because it is not a US model. Anyone know where I can find a serial number list for the Korean-made Celebrity?
Interesting note - I did see a CC057 (Black) in the store that did have the new OP20 preamp... Looks very cool...
Thanks for any help! |
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December 2002
Posts: 13
Location: Pittsburgh, PA | Piercer34,
I think it's not only possible but probable that the display model you saw (and the guitar I bought) was a 2001-built model.
In my case, since the guitar I bought was the same one I played and liked from the store display, it doesn't bother me too much (I knew I wasn't getting a tuner, for example). Unless, of course, the newer electronics have better RF shielding... |
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December 2002
Posts: 13
Location: Connecticut | I finally received my CK057. It has the new OP-20 preamp. Sounds sweet, I didn't know it came with a guitar bag.. |
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December 2002
Posts: 19
| Have you tried looping the wires (several times) that go from the pre-amp to the pickup through the ferrite bead? Place the ferrite bead closer to the preamp than the pickup. This should stop any RF from getting into the pre-amp. If that doesn't work, then my guess is that something in the preamp is acting as an oscillator and picking up the strong field RF of the radio station, in which case ferrite beading the input to the preamp and shielding the preamp might help.
Also, are you sure that it is not your amp that the rf is getting into? Have you tried pluging in other guitars into the amp with the same cord? Amps have a tendency to turn into radio receivers at times. Good luck, Tim |
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Posts: 13
Location: Pittsburgh, PA | Originally posted by kb5zcr:
Have you tried looping the wires (several times) that go from the pre-amp to the pickup through the ferrite bead?
That's my next approach. I was going to wait for Ovation to get back to me from my over-the-holidays inquiry, but if it gets to be a couple more days I may not wait. One complication is that when I remove the strings it stops, so I can't listen while placing the bead and adjust for optimal placement.
Place the ferrite bead closer to the preamp than the pickup.
Thanks; I'll try that placement first. (I may go through a couple of sets of strings before I'm done, so any advice on where to start is appreciated.)
Also, are you sure that it is not your amp that the rf is getting into? Have you tried pluging in other guitars into the amp with the same cord?
I don't have any other electric guitars, but I am sure that it's the guitar and not the amp (actually a POD), since I've plugged it into other things and still heard the interference, and don't get interference when other gear is used in those inputs.
Thanks for your input. I'll post here if this fixes it or if/when I get anything else that solves it. |
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December 2002
Posts: 13
Location: Pittsburgh, PA | Resurrecting an older thread...
I haven't had any luck solving my radio interference problem. :confused:
I'd just been practicing acoustic, and not worried too much about the electronics, but I wanted to solve this problem and had some time tonight.
Tonight I put an RF choke on the wiring bundle inside the guitar (had to loosen the strings to get my hand inside the sound hole) but to no avail.
I recorded this (4MB WAV), on which you can clearly hear the radio station. (WARNING: crappy playing alert. I'm a beginning guitarist.) This is direct from guitar to POD2.0 to MOTU 2408 (recorded 24-bit and put thru Waves +L1 for normalization and dither to 16-bit).
Is this normal? Should I be satisfied with this? Am I crying wolf, or does this suck like I think it does?
(Recap: I've isolated the problem to the guitar, and I live 3/4 mile from the 44kW transmitter.) |
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Posts: 1498
Location: San Bernardino, California | 44 Kilowatts is a lot of power so your problem may be difficult to solve. My best guess as to where to install any RF filter is at the input to the preamp in the guitar (between the pickup and the preamp). A 100 uH coil in series with the hot lead with a 100 thru 250 pF capacitor to ground are fairly standard values. |
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December 2001
Posts: 7247
Location: The Great Pacific Northwest | Hmmm Does the "reception" change as you move the guitar around, and does it do it in all parts of the house? What freq is the radio station? I dealt a lot with radio broadcast back in the day... Harmonic bleed is expected... but they are doing what's called "splatter" if it's coming in clear. It could be as simple as a filter on their transmitter leaking to as complicated as length of one of the wires on the fence matching a harmonic length and acting as a passive tranmistter of the bad frequency. A CLEAN transmitter does not bleed. Take a look at the top of a Navy ship the next time you see one. There are a TON of transmitters (especially on Carriers) all right next to each other, and we were all be below decks listening to shipboard radio station or local radio stations when in range on our cheapo boom boxes. If you were a couple hundred feet from the antenna, that would be a little different, but you are far enough away. If approaching the radio station achieves nothing (and you must approach them first).. then write a nice letter to the FCC. I'm sure your playing is just as important as how many times Howard hits the beep or how many times some 17 year old cb radio user uses his callsign in an hour. (do they still use CB radios? I see them for sale still) |
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Location: Las Cruces, NM | Djehuti
Not to wish you any bad luck, but I find this thread very interesting. Kind of like a mystery with various theories. In the early days of radio there were many stories of people receiving broadcasts on various media, for example, tooth fillings (hard to believe as sound requires a vibrating medium). Nowadays there are rules against radio interference, I think you should invite an engineer from the station you are receiving to hear your reception and if he blames your guitar, at least he can tell Ovation why he thinks it's at fault in scientific terms, if not, he might be at fault.
Interesting thread, needs resolving.
Bailey |
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Posts: 7247
Location: The Great Pacific Northwest | "tooth fillings" never heard of fillings, but "braces" I have heard of. I don't recall exactly why, but something to do with the metal and teeth making a component...
I used to have forms to send TV companies to supply the FREE filter that was supposed to be in TV's to block them from radiating RF harmonics at close range. The form cited the FCC directice that makes them responsible. I believe it is still the rule that it is a requirement of the TRANSMITTER to be clean, not the reciever to have a good filter. It was a little trick most of the TV companies pulled in the 70's to save money. They eliminated the filter circuit and called it "improved reception" then just supplied a free RF filter to anyone who actully had a problem or just asked for that matter. (TV's actually emit a small amount of RF eventhough they are a receiver).
Anyway, I'd like to hear the resolution from them. I will look up the FCC reg as I bet now it's online. Unless your guitar is designed as a reciever, or there is some fluke of Nature, in the year of 2003 you should NOT have ANY interference from RF. |
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Radio interference on CK057
