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Message |
    
Chad
Advanced Member
Username: Chad
Post Number: 514
Registered: 11-2004
| | Posted on Friday, October 21, 2005 - 12:19 pm: | 
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The Noise chopper by Valor? Copper sells it. I am having trouble with fuel pump noise getting into the antenna system. A NB circuit would solve the probelm but this radio does not have one. I am going out today at lunch to grab some ferrites for the fuel pump supply wiring but was also wondering the effectiveness of this device.
I should just buy a different radio but the Cobra 75WXST hides sooo well in my console storage box!
Chad |
Allagator
Advanced Member
Username: Allagator
Post Number: 707
Registered: 9-2002
| | Posted on Friday, October 21, 2005 - 4:13 pm: |
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Chad i ran one in my mustang to kill the noise from the power windows and it hill most of my noise !(white noise )and some of my locals sound way out there now ! so i took it off there and done some grounding for the doors and he helped a bunch !
now if i could just get that thud sound out when i lock the doors ! LOL
Hope it helps !!!
Allagator |
Rover
Intermediate Member
Username: Rover
Post Number: 286
Registered: 2-2004
| | Posted on Friday, October 21, 2005 - 7:03 pm: |
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Does that make a Mustang a "THUD-DER-BIRD"? LOL!
J/K 
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Allagator
Advanced Member
Username: Allagator
Post Number: 708
Registered: 9-2002
| | Posted on Friday, October 21, 2005 - 7:24 pm: |
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at times it does ! LOL its just how high you jump it ! LOL
funny thing is the rear hatch and fuel door latch dont make that sound !
ford messed up when they went all power ! LOL
but i still love my toy ! LOL
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Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 278
Registered: 4-2005
| | Posted on Friday, October 21, 2005 - 9:41 pm: |
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I used the ferrite clips in my Grand Cherokee. I put one on each fuel pump wire (Hot/Neg) and cut the noise by 75%. You have to put it as close to the source as possible. Now that the Grant has reclaimed its spot in the mobile I hardly notice it at all but the S-9 was very sensitive to all outside noises. Sorry but that radio had a lame NB system.
BTW...how good/fresh is your coax? When I changed my older RG8X to fresh stuff it also eliminated a LOT of the noise. Can't wait to see how good it gets with the Super240.
Hank '905
CEF 559 |
Chad
Advanced Member
Username: Chad
Post Number: 515
Registered: 11-2004
| | Posted on Saturday, October 22, 2005 - 12:08 am: |
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Thanks for the heads up gator, it seemed a little too good to be true
The Coax is fresh but not that great. I had to go with a smaller diameter coax to squeeze thru the tight hatch crack. That radio was sensitive to pump noise in the truck too and I had nice coax in that. Tha antenna is also close to the pump in this install.
Fortunately I can get quite close to the pump even from inside the cabin. It goes straight from the floor of the hatch into the tank directly below. I did not have time to run to the shaq today to get ferrites. I was busy fnding the ONE Autozone that had Mobil 1 5W20!
I would not be opposed to a different radio, My dash is CRYING for a custom fiberglass install of a Magnum 257 directly under the stereo. man If i could just paint it silver to match the dash and have Magnum re-silk screen the lettering
The mini magnum caught my attention from what Lon has said but it does not have a NB either. The only mini type radio that does seems to be the Uniden PRO510XL, and honestly, I have heard great things about them!
I really like this Cobra, this is it's 3rd vehicle, and for me to transfer radios like that is rare. It is feature rich, talks great, and is invisible. If I could just have NB/ANL (I would happily trade "presets") and an easy way to lower the DK I would be all set I guess you can't have your cake and eat it too!
Chad |
Bigbob
Senior Member
Username: Bigbob
Post Number: 2247
Registered: 12-2001
| | Posted on Saturday, October 22, 2005 - 5:40 am: |
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Don't worry the cake doesn't taste that good,got a pc-122 with a nb/anl and it kills the noise about 25% on am and 50% on ssb,put some caps in speaker and got another 50%,thought of ferrite but have about 5000 wires going to fuel tank in a huge harness and can't determine which is the +/- for the pump,so I settled on 2 25mfd nonpolarised caps across the speaker leads,they just fit as this is a tiny radio too.Bigbob |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 421
Registered: 11-2002
| | Posted on Saturday, October 22, 2005 - 1:52 pm: |
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What about when you turn your A/C blower motor up? When I cut my A/C on, I can hear a change in my receive, even with the blower motor on low. Anything higher, and I may as well hang it up.
What can I do to stop or reduce this noise? |
Hollowpoint445
Advanced Member
Username: Hollowpoint445
Post Number: 848
Registered: 6-2004
| | Posted on Saturday, October 22, 2005 - 6:22 pm: |
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Bypass capacitors at the motor will cut it down dramatically, if not totally eliminate motor noise. I've done it in three different cars (2 gas, one diesel) for the blower motor and windshield wipers, and I could run with the NB/ANL off. In traffic, other cars were an issue, but the NB took care of that.
Ferrite beads may help, but my experience with bypass capacitors has been so positive I've never tried them. I don't have a problem with cutting wires, so the capacitors work great for me.
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1744
Registered: 7-2004
| | Posted on Saturday, October 22, 2005 - 8:07 pm: |
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when i deicided to 'serious' the durango & removed the radio shack mag mount & replaced with triple mount with double shield rg8x, AC noise DISAPPEARED...COAX-COAX-COAX-COAX-COAX...then i went 9913 |
Chad
Advanced Member
Username: Chad
Post Number: 518
Registered: 11-2004
| | Posted on Saturday, October 22, 2005 - 9:36 pm: |
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When I terminated the coax it looked as if it had a decent shield, it's just thinner wire, thinner inner conductor and dielectric. Blower is fine, Wipers are fine, even the rear wiper by the antenna. The coax passes by a power amp with a switch mode supply, no problem, the car has electric steering, no hydraulic pump, no problem there. It's that darn pump! I'll tackle it next week Ferrites first, Then more drastic.
Chad |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 423
Registered: 11-2002
| | Posted on Monday, October 24, 2005 - 10:33 am: |
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Where can I get bypass caps and of what value or is there only one? And how do you install them, as I've never done that before. I don't have a problem clipping a wire either.
I plan to upgrade coax for sure also. I bought the triple mag mount. The coax claims 98% shield, but I used the stock wilson coax from the 5000 mag mount. I had to do a little modification to get it to mount on the trimag, but it's there and working well, I assume. The trimag came with a setup for an antenna like the Wilson truckers, and once I took that apart, I could see that it was a pretty crappy setup.
Nothing was soldered, they were just pressed together, so I knew that wasn't going to work. You think I should try that coax instead of the stock Wilson coax or if I'm going to that much trouble, just go ahead and buy something I know is better than what I have? |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1758
Registered: 7-2004
| | Posted on Monday, October 24, 2005 - 12:08 pm: |
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i even removed the ball mount from my triple, & replaced with predator lug mount. 1st with coax it came with, then 9913. the stock wilson coax is not a heavy shield-slit it open & peel back cover, you'll see lots of 'white' through the shield. exactly what you DON'T want.
maybe my mobile would sound EXACTLY the same as it does now if i used a crappy mount & coax. but then again, maybe it wouldn't.
i will continue to mount 'em as i do now, & recommend they be done that way |
Hollowpoint445
Advanced Member
Username: Hollowpoint445
Post Number: 855
Registered: 6-2004
| | Posted on Monday, October 24, 2005 - 9:33 pm: |
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I used to buy something called a "feed through filter capacitor" at the big electronics chain store for about $5, but I don't think they carry them anymore. If you can find them elsewhere they're great because you can just mount it close to the offending RF source, cut the power wire, strip both ends, and connect them to either end of the filter. It can handle loads of up to 40 amps, but all it basically does is feed the current through and bypass the RF to ground with a capacitor.
If you can't find one you can use a capacitor of at least 1/2 picofarad connected from the power wire to ground. Get it as close to the motor as possible to eliminate the most noise. |
Chad
Advanced Member
Username: Chad
Post Number: 525
Registered: 11-2004
| | Posted on Monday, October 24, 2005 - 9:47 pm: |
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They make active filters now that do this. I don't have a problem strapping a cap across it, I ain't cutting wires to the fuel pump and inserting a five dollar device, if the cap fails it still goes down the road Maybe i'm picky, caps and ferrites should be a 12DB LP filter correct? As in Cap-> ferrites-> cap, wait, that 18DB! |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 428
Registered: 11-2002
| | Posted on Thursday, October 27, 2005 - 12:38 am: |
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Where can I get those at Chad?
There has to something I can do to cut down or remove that noise. I have noticed that if I disconnect the coax I don't hear it. So wouldn't that be RFI created by the motor running, being emitted out into the air and picked up by the antenna?
What can you use to shield the blower motor? |
Chad
Advanced Member
Username: Chad
Post Number: 537
Registered: 11-2004
| | Posted on Thursday, October 27, 2005 - 10:06 am: |
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Yes it can be emitted from the motor but more likely it is creeping into the electrical system and the wiring is becoming the radiator, the DC is filtered (some) before it goes into the radio.
Active filters can be had from many places that sell car-audio. Here's the pricey ones, but they use a TO-3 device!
http://www.autosound2000.com/filters.html
Chad
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Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 435
Registered: 11-2002
| | Posted on Thursday, October 27, 2005 - 11:48 pm: |
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Oh cool. I don't care what it cost if it works. Which one do you think it'll take to do the job or should I just buy the biggest one and be done with it?
What about that shielding tape? Should I get some of that and wrap the blower motor in it? |
Chad
Advanced Member
Username: Chad
Post Number: 539
Registered: 11-2004
| | Posted on Friday, October 28, 2005 - 9:06 am: |
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The blower motor is metal right? Is it grounded? or sitting on a plastic fan housing? That motor bell should be providing some sheilding.
I'd go large on the filter, but again,do keep in mind there are equal and cheaper ones out there, that website was just on the top of my head. I'm going to try ferrites and bypass caps first, then go more drastic.
Chad |
Therealporkchop
Intermediate Member
Username: Therealporkchop
Post Number: 437
Registered: 11-2002
| | Posted on Saturday, October 29, 2005 - 12:27 am: |
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Yeah, to my knowledge it's sitting in a plastic heater box. So it's probably not grounded other than the +/- wires connected to it. I'll try grounding sometime this weekend and see if that alone helps any. If not, then I'll check into one of those thingies on that page.
Thanks! |
