Guest leopoldstotch Posted October 5, 2006 Report Share Posted October 5, 2006 Sorry to start a new thread but I'd like everyone to see this and offer advice. Well as you may know my mid is not dead the problem is that the midranges coil is the problem. I installed new pots and that is when I discovered this problem. While leaving the woofer out I turned on my receiver on low volume and still had no sound from the mid but upon moving the coil wire attached to the pot that is when I discovered the coil is not working properly it needs to be moved around to a certain spot in order for it to work. Can the midrange coil be repalced and if so what coil should I get and where should I get it from a link would be helpful if it's replaceable. Thanks. Bruce Link to comment Share on other sites More sharing options...
onplane Posted October 5, 2006 Report Share Posted October 5, 2006 Bruce,It's pretty unusual for a coil to have an intermittent problem. Usually they are open or they work.Any chance you have a bad connection where that coil connects with the other coil and the resistor?Regards,Jerry Link to comment Share on other sites More sharing options...
Guest leopoldstotch Posted October 5, 2006 Report Share Posted October 5, 2006 No Jerry I double checked and the connections are good. Link to comment Share on other sites More sharing options...
RoyC Posted October 6, 2006 Report Share Posted October 6, 2006 >Can the midrange coil be>repalced and if so what coil should I get and where should I>get it from a link would be helpful if it's replaceable.Bruce,It is very unusual for a coil to be a problem in the way that you describe. Attached is a photo of the 3a midrange coils and attached resistor wire (between the rivets). Make sure the problem is not the resistor wire and/or connections in that area of the crossover.If it really is the coil, the best replacement would be a used AR #4 (.88mh) coil. AR coils were wound with 17ga wire, which you will not easily find today.Royhttp://www.classicspeakerpages.net/dc/user_files/1631.jpg Link to comment Share on other sites More sharing options...
onplane Posted October 6, 2006 Report Share Posted October 6, 2006 Hi, Roy!!If the problem really was the coil (and like you I doubt it is), could he unwind the coil and look for a break??Roy, please bear with me as I'm just thinking out loud here. The coil is really a spool of wire. If he unwound, fixed the break and re-wound in EXACTLY the same fashion, is it possible that he could repair it?What do you think, Roy?Regards,Jerry Link to comment Share on other sites More sharing options...
tysontom Posted October 6, 2006 Report Share Posted October 6, 2006 >Sorry to start a new thread but I'd like everyone to see this>and offer advice. Well as you may know my mid is not dead the>problem is that the midranges coil is the problem. I installed>new pots and that is when I discovered this problem. While>leaving the woofer out I turned on my receiver on low volume>and still had no sound from the mid but upon moving the coil>wire attached to the pot that is when I discovered the coil is>not working properly it needs to be moved around to a certain>spot in order for it to work. Can the midrange coil be>repalced and if so what coil should I get and where should I>get it from a link would be helpful if it's replaceable.>Thanks.> It really sounds like a bad or "cold-solder" joint as a result of installation of new controls. It is possible, but extremely unlikely, that a coil would give trouble unless the crossover was exposed to very high output current from an amp, in which case a coil's windings could overheat and short together internally. The reality is that the entire crossover would have been destroyed in that event.Go back and carefully re-heat each and every solder joint. Hopefully that will restore operation.--Tom Tyson Link to comment Share on other sites More sharing options...
RoyC Posted October 6, 2006 Report Share Posted October 6, 2006 >If he unwound, fixed the>break and re-wound in EXACTLY the same fashion, is it possible>that he could repair it?>>What do you think, Roy?Hi Jerry,Sure, magnet wire can be soldered together and the mended area re-coated, but unless the coil was somehow defective from the factory it is very unlikely that the problem is simply a broken wire. Also, once we get into winding and unwinding coils, it becomes rather necessary to have a meter to measure the coil's inductance. If the coil melted or fused it would no longer be usable, and as Tom pointed out, other areas of the crossover would likely have been affected by anything that would have caused that to happen.I think we are all in agreement that connections and solder joints are the most common cause of this type of problem. I have run across a couple of AR-3a coils (#9 woofer coils) that were out of spec, but none that were intermittent or not working at all.Roy Link to comment Share on other sites More sharing options...
JoeB Posted October 6, 2006 Report Share Posted October 6, 2006 >Sorry to start a new thread but I'd like everyone to see this>and offer advice. Well as you may know my mid is not dead the>problem is that the midranges coil is the problem. I installed>new pots and that is when I discovered this problem. While>leaving the woofer out I turned on my receiver on low volume>and still had no sound from the mid but upon moving the coil>wire attached to the pot that is when I discovered the coil is>not working properly it needs to be moved around to a certain>spot in order for it to work. Can the midrange coil be>repalced and if so what coil should I get and where should I>get it from a link would be helpful if it's replaceable.>Thanks.> BruceThe mid coil is normally soldered directly to the pot. If you cut the previous connection you must clean the insulation off very well to resolder. I prefer to scrape the insulation off and solder a short jumper to the end of the coil which makes it much easier to install. That insulation on the magnet wire is very tough stuff. Link to comment Share on other sites More sharing options...
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