Condor Posted October 31, 2011 #1 Posted October 31, 2011 Need some advice. I just replaced my tired Kenwood analog tuner with a not so tired Pioneer digital. When I try to listen to AM signals I get a hum... or I guess feedback... in the speakers, when I go to FM it sounds fine. I've checked the +/- continuity for the speakers and they are correct. I'm no expert when it comes to messing with audio stuff, so anyone a lot smarter than me have any ideas what might cause the AM hum??
etcswjoe Posted October 31, 2011 #2 Posted October 31, 2011 Do you get the hum with only when it is running or all the time? If you get it only when you are running you need a filter cap. If you get it when you are not running you are most like reciving external interference such as if you are in the garage you will pick up noise from the florescent lights.
SilvrT Posted October 31, 2011 #3 Posted October 31, 2011 If you get it only when you are running you need a filter cap. If you get it when you are not running you are most like reciving external interference such as if you are in the garage you will pick up noise from the florescent lights. There you go Jack... just put a "filter" cap on and you'll be able to run the marathon!
Marcarl Posted October 31, 2011 #4 Posted October 31, 2011 Need some advice. I just replaced my tired Kenwood analog tuner with a not so tired Pioneer digital. When I try to listen to AM signals I get a hum... or I guess feedback... in the speakers, when I go to FM it sounds fine. I've checked the +/- continuity for the speakers and they are correct. I'm no expert when it comes to messing with audio stuff, so anyone a lot smarter than me have any ideas what might cause the AM hum?? Need more info,,,, is the tuner an amp as well,,,,,, house unit or on the bike,,, what else is hooked up to it,,,,, power output,,,,, antenna attached.
etcswjoe Posted October 31, 2011 #5 Posted October 31, 2011 There you go Jack... just put a "filter" cap on and you'll be able to run the marathon! Need to pass that to Yammer Dan since he is working out now.
bongobobny Posted October 31, 2011 #6 Posted October 31, 2011 Try putting a good ground on the chassis. What are you using for an AM antenna?? I have some nice vintage early 90's Rotel equipment I might think of parting with if you want some serious Audiophile quality equipment..
dacheedah Posted October 31, 2011 #7 Posted October 31, 2011 The hum is likely caused by a ground loop. Two or more items are grounded and the distance from the ground is different. AM is subject to noise, it is the way an ole timer could tell a storm was on the way, you can actually hear the static from the storm on the am radio.
Condor Posted October 31, 2011 Author #8 Posted October 31, 2011 Well, I turned it to AM and got the humm/buzz Then turned off the office fluorescents. Bingo!! I still get a little noise between AM stations, but when I pull in a strong signal I can't hear a thing... except the station. Yes, the tuner is amp'd, and the antenna is a length of appliance power cord sorta split into a di-pole and tacked to the upright of the bookcase. Works. There is also a short.. 6".. what looks like a shorty antenna on the back of the tuner. Now here's the problem. How can I filter out the flourescent noise? Do they make flourescents tubes that are noise free?? Or would I have to replace the whole light with a different ballast?? Thanks for the ideas and help so far...
Condor Posted October 31, 2011 Author #9 Posted October 31, 2011 Try putting a good ground on the chassis. What are you using for an AM antenna?? I have some nice vintage early 90's Rotel equipment I might think of parting with if you want some serious Audiophile quality equipment.. Thanks Bob. I have everything running off the same circut... it's a remote barn shed office... Would it be possible to filter the power source like we use to do with the mobile CB's. Rotel is nice stuff, but no way I could afford it....
Marcarl Posted October 31, 2011 #10 Posted October 31, 2011 You could drive a stake into the ground and then ground the tuner from there. You'll need about 3' to 4' into the ground. The other thing to try is to run the antenna outside,, might give you enough reception to overcome the buzz. Also, check to make sure the fluorescent is grounded,,, can make a difference. It didn't for me in my shop, but it make work for you.
bongobobny Posted November 1, 2011 #11 Posted November 1, 2011 Yah! What Carl says! Unfortunately, with flourescent lights, it's the high voltage travelling across the tube that generates the RF interferience. You could try making sure the fixtures have a good ground. I never listen to AM so I'm not much help there. The reason I have Rotel is back in the early 90's I was the lead technician for the national distribution and repair center fior Rotel Stereo and B&W loudspeakers...
dacheedah Posted November 1, 2011 #12 Posted November 1, 2011 just replace it with an led, expensive but cheap to run
Condor Posted November 1, 2011 Author #13 Posted November 1, 2011 The reason I have Rotel is back in the early 90's I was the lead technician for the national distribution and repair center fior Rotel Stereo and B&W loudspeakers... Ain't company perks great!!
rod Posted November 1, 2011 #14 Posted November 1, 2011 Make sure the ballast on the fixture is grounded to the case. Make sure the stereo case is grounded that should do the trick. Electronic ballasts make less noise than the old magnetic; cheap fixtures are nosier than the better quality fixtures. Rod
bongobobny Posted November 1, 2011 #16 Posted November 1, 2011 That would be ANCIENT Modulation there Buddy...
Condor Posted November 1, 2011 Author #18 Posted November 1, 2011 What the heck is AM???:rotf: Hoping this won't go polical... but KFBK 1530/FOXNEWS is AM.....
bongobobny Posted November 1, 2011 #19 Posted November 1, 2011 Hmmmm, a lot of us listen to satellite, fox news is on that...
Freebird Posted November 1, 2011 #20 Posted November 1, 2011 and a one...and a two...and a......................
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