| Author |
Message |
    
Al_lafon
Junior Member
Username: Al_lafon
Post Number: 29
Registered: 3-2005
| | Posted on Thursday, June 02, 2005 - 11:29 am: | 
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Hello anyone having problem with high ac line noise in the 3900 or know a fix ? |
Bruce
Senior Member
Username: Bruce
Post Number: 2778
Registered: 9-2003
| | Posted on Thursday, June 02, 2005 - 1:56 pm: |
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if you meen from the outside you need to contact the power company |
Tech808
Moderator
Username: Tech808
Post Number: 5944
Registered: 8-2002
| | Posted on Thursday, June 02, 2005 - 7:40 pm: |
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Al_lafon,
Do you get this interference ONLY with the 3900 or with all radios you try and use?
You could be getting interference from any number of sources as well as the local power lines or something located in or around your house.
Are you using this in a Mobile or Base setup?
It you are using it in a mobile set up, you should be able to drive around and locate the problem as the noise get's louder.
Lon
Tech808
CEF808
N9OSN |
Al_lafon
Junior Member
Username: Al_lafon
Post Number: 32
Registered: 3-2005
| | Posted on Thursday, June 02, 2005 - 9:35 pm: |
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This is in a Mobile setup seems like all the local power lines have high noise around them.
Also get noise at the lights. |
Bruce
Senior Member
Username: Bruce
Post Number: 2785
Registered: 9-2003
| | Posted on Friday, June 03, 2005 - 7:13 am: |
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Some lines are so bad they wipe out 2 meters!
Most power companys if you can tell them where its the worse will make a efford to fix it.
And if they dont well in realy bad cases the FCC will help .......
"The Federal Communications Commission notified Duquesne Light, on December 17, 2002, that it had received a complaint of harmful radio interference apparently caused by power line hardware owned by Duquesne Light. " |
Al_lafon
Junior Member
Username: Al_lafon
Post Number: 33
Registered: 3-2005
| | Posted on Friday, June 03, 2005 - 11:41 am: |
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Yes this is all good info but can i do domething
to the radio to help with this. |
Al_lafon
Junior Member
Username: Al_lafon
Post Number: 34
Registered: 3-2005
| | Posted on Friday, June 03, 2005 - 11:50 am: |
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OK sorry let me put it this way i am looking for
mods that will clean up the rec. in this radio
main boad is ept690010c like known bugs or fixs
that may be out on this radio |
Vanillagorilla
Member
Username: Vanillagorilla
Post Number: 52
Registered: 4-2005
| | Posted on Friday, June 03, 2005 - 2:17 pm: |
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A noise filter could be an option but I've never used one that worked as well as I thought it should...BTW it not just your radio. It'll happen to all my radios including My 3900 , Grant XL and 148GTL. Traffic lights I get the buzzing/Whirr that sounds like a small plane is landing on my roof and the High tension wires wreak havok on my recieve! I only saw a difference when I swapped a fiberglass Francis 5.5' whip on my roof in place of the Steel Wilson 2000. I have to say the Wilson was the better antenna overall so I swapped back and I chose to live with some interferance...the vol. or squelch is only an arms length away . 
Good luck!
Hank '905
CEF 559 |
Al_lafon
Junior Member
Username: Al_lafon
Post Number: 35
Registered: 3-2005
| | Posted on Friday, June 03, 2005 - 9:58 pm: |
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OK maybe thats it using a Wilson 2000 here last time i had a radio was back in the mid 80s and
was using full 1/4 wave on the pickup i had.
I was running a jackson then also. i don't remember hearing that much noise from ac lines
or stop lights. Will be changing out frist amp
transistor to a 2sc2999 i do know that help some
i'd like to find some more tips or tricks for this
radio if someone has links or notes it be real nice. |
Bruce
Senior Member
Username: Bruce
Post Number: 2794
Registered: 9-2003
| | Posted on Friday, June 03, 2005 - 10:59 pm: |
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does the 3900 use a 2sc1674 rf stage? |
Al_lafon
Junior Member
Username: Al_lafon
Post Number: 41
Registered: 3-2005
| | Posted on Tuesday, June 21, 2005 - 10:01 pm: |
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Ok i changed the frist rf amp in the radio tr or q 17 to a 2SC2999 that did a real good job of cleaning up this radio. |
Bruce
Senior Member
Username: Bruce
Post Number: 2877
Registered: 9-2003
| | Posted on Tuesday, June 21, 2005 - 10:45 pm: |
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yep the 2999 realy does help! |
Yankee
Advanced Member
Username: Yankee
Post Number: 691
Registered: 7-2003
| | Posted on Wednesday, June 22, 2005 - 2:03 pm: |
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Just for a because. On my '89 Mercury Sable that has an in tank 12 volt fuel pump. My Cobra 138 XLR picks up so much noise from the pump and other electronics in the car, that the 138 XLR is all but useless in the mobile. And now the just because, I for just a few days changed radios to my radio I run base the Uniden Grant XL, now this was before the Grant had the change to the 2SC2999 and the Grant cleaned up about 90% of the noise, still got a little noise off the directionals and wiper motor, but not near as bad as my Cobra 138 XLR. Comes down to that the filtering in the Cobra 148 GTL, 148F GTL, Uniden Grant XL/LT is that good even before the transistor change. Looking for a good 148 or Grant to keep set up for the mobile.
Carl CEF/357 |
Hotwire
Intermediate Member
Username: Hotwire
Post Number: 410
Registered: 1-2005
| | Posted on Saturday, June 25, 2005 - 2:35 pm: |
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My Imax is near my house power lines, it was about 5 feet away and I got terrible ac noise. I elevated the antenna 30 feet higher and it totally eliminated all the noise. For mobile I have a good NB/ANL and use an antenna with plastic shell. I CAN tell between a plastic wrapped antenna and a bare antenna. |
Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 678
Registered: 7-2004
| | Posted on Saturday, June 25, 2005 - 3:11 pm: |
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I also get bad powerline noise here
in my area in PA. Around town my
mobile radio buzzes up a storm.
When you get to the out-skirts of town
it quiets down. |
