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December 2008
Posts: 5
Location: Newcastle, WA | My Custom Balladeer 1860 picks up FM when plugged into any system. Does anyone know how to filter out these frequencies?
Thanks,
Indy |
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Joined:
December 2006
Posts: 6268
Location: Florida Central Gulf Coast | Until the 'pros' show up to assist you, I would say to ensure that all of your electronic equipment is properly grounded. That third grounding prong can be critical for 'clean' signals. Also any shielding (i.e. cords) should be complete with no breaks. |
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December 2008
Posts: 5
Location: Newcastle, WA | The problem is without doubt within the 1860. I don't get this with any of my others, including the other Ovation I own. It is my A/E of choice to play, but brings in signal even through the house system at church..... :( |
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September 2003
Posts: 9301
Location: south east Michigan | My Breadwinner has a nasty habit of picking up radio signals. Mostly truck dispatcher type stuff. |
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Joined:
December 2006
Posts: 6268
Location: Florida Central Gulf Coast | In that case, ensure ALL the soldered connections (preamp/jacks/leads) are complete with no shield/wiring breaks.
The FM signal is 'leaking' in somewheres in your circuit.
Sorry, that's all I can suggest... |
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March 2005
Posts: 12750
Location: Boise, Idaho | My Ute does that, but only when the plug isn't all the way in. It should be a Spanish guitar, cuz the station it picks up is in Spanish. |
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Joined:
April 2008
Posts: 30
Location: Indiana | I think some questions might be in order.
1) do other owners of the same model have the same problem? (which suggests something quirky with that one if so)
2) is the audio from the outside radio source fairly "clean" or is it kinda grungy sounding?
I ask #2 because sometimes any number of kinds of crappy connections, even bad solder joints, can act as "detector diodes" would in an actual radio receiver. I don't know which electronics you have in that one so it's hard to pinpoint, but possibly going over those connections carefully would reveal one or more bad ones. Depending on your skill level with a soldering iron, you could go through and resolder anything questionable which might solve the problem. Certainly any GROUND connections that are bad should be addressed.
3) Are you able to determine if this only happens if you are in close proximity to the source of the transmissions, assuming that the audio is heard clearly enough to identify them?
Typically, "spurious reception" is "broad-banded" - that is, you won't be just picking up one single channel/frequency but several over a fairly wide range of bands/services. That's typical in this case IFFFF caused by a lousy connection in what is strictly an AUDIO device (like a preamp module might be considered) as opposed to say, if you were using an RF link with transmitter on your guitar and receiver at your amp (that's a whole other can of worms!)
OTOH, if you are picking up only one station or transmitter source the problem MIGHT not be your guitar.....radio transmitters have been known to develop faults that generate spurious junk that cause interference, AND if you're just plain physically close to a reasonably powerful transmitter (even one that is transmitting a clean signal) it can get into all sorts of stuff.
Illegally modified CB radios are a frequent culprit although that doesn't match your "FM" comment if you're suggesting the FM broadcast band. Are you close to the transmitter of an FM radio station, if that is the case?
Filtration: technically speaking, inserting a "low pass filter" into your line between guitar and whatever is next, effects or amp, would possibly be effective against a signal from the 88 to 108 MHz FM broadcast band. *Finding* one is probably going to be a pain. Without getting overly technical about it (background - aside from a degree in Electrical Engineering Technology, I am also an Extra Class Amateur Radio operator which is the highest level of ham license offered in the USA so I do have some background dealing with unwanted interactions between radios and audio/TV gear) what you want is something that will PASS frequencies in the audio range (generally figure at 22 to 25 KHz and DOWN) and reject/block anything HIGHER than that.
The nasty part of this problem is....IFFF what you're dealing with is something in the guitar's electronics is picking up the radio signal and acting like a receiver, then what your guitar is dumping down the cable to the amp is probably already in the audio range. IFFFFF that is the case, the low pass filter would pass it as being within the aduio frequency range. OTOH, if your guitar is simply passing the raw radio signal down the cable where the *amp* is separating the audio from the RF signal, THEN the low pass would work.
I did just a quick search for low pass filters and didn't find anything that seemed appropriate as a simple in-line device.
From 30-some years worth of experience I hate to say it, but this sort of thing can be anywhere from one crappy solder joint all the way up to a complicated mess and anywhere inbetween. Start with the simple stuff - try and identify the transmission source........and if you can, check the wiring and/or module in your guitar and see if there are any bad connections, to the best of whatever your personal skill level is.
If you want to discuss it off-board, I think my email link should work...
Duane
WB9OMC |
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Joined:
December 2008
Posts: 5
Location: Newcastle, WA | Thanks for the info Duane. The problem is with the preamp in the guitar. Signal varies, but does come in clear albeit at low levels. Can't use it live. I believe I will yard out the module and see if I can see anything obvious, and if not see if I can have someone look at it for me. It is a great guitar, and I would love to be able to use it more often, but until I solve this, it is for practice at home only.
Indy |
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August 2008
Posts: 121
Location: Maine | The question would be; is it just one radio station that you are having a problem with, or multiple stations. If multiple stations on the frequency band is giving you a problem, then that problem is yours. If, however, you are getting this from only one radio station, that station could be over modulating, which is against FCC regulations. The situation should be addressed with the station manager first. They should have their engineer check to see if there is a problem on there end and get back to you. If they don't, contact the FCC and they will look into the problem. |
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October 2008
Posts: 489
| Does this happen at a particular time of the day? I have a Carvin PA head that picks up commercial radio at sundown, no other time. I like the box, but if I have a sundown gig, I use something else.
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Joined:
April 2008
Posts: 30
Location: Indiana | Originally posted by Wagonmaster:
The question would be; is it just one radio station that you are having a problem with, or multiple stations. If multiple stations on the frequency band is giving you a problem, then that problem is yours. If, however, you are getting this from only one radio station, that station could be over modulating, which is against FCC regulations. The situation should be addressed with the station manager first. They should have their engineer check to see if there is a problem on there end and get back to you. If they don't, contact the FCC and they will look into the problem. EXACTLY correct. Wagon, you into radio?
Duane
WB9OMC |
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FM Interference Help
