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Maxgain
Member Username: Maxgain
Post Number: 51 Registered: 3-2007
| Posted on Wednesday, February 11, 2009 - 10:24 pm: |
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I have noticed that my I-max 2000 picks up a LOT of noise. I have been very happy with the transmit performance but I would like to try an omnidirectional vertical base antenna that will not be prone to picking up so much general random static. Would any of these be recommended for quieter reception?, Top-One (astroplane), Maco-V-5/8, any others? What would you recommend ? Thanks for your help! |
Starface
Senior Member Username: Starface
Post Number: 2313 Registered: 1-2005
| Posted on Thursday, February 12, 2009 - 12:04 am: |
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If the antenna is Grounded good (along with everything else)it should be quite. George/KI4NBE/Starface CEF Ø476/CVC ØØ14/CEF HAM Ø181 CEF Southeast Net Controller
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Bruce
Senior Member Username: Bruce
Post Number: 4974 Registered: 9-2003
| Posted on Thursday, February 12, 2009 - 6:10 am: |
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A "DC" grounded antenna will bleed off static but if the noise is within the bandwidth of the antenna you will still hear it. Fiberglass antennas tend to be a bit noiser that all medal but CSPC rules require safety standards for CB base antennas this is why they are mostly fiberglass but you can buy a 10 meter one of those if you want to give it a try. I run verticals from 20 - 3/4 meters a mix of both types here. On 6 since 66
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Maxgain
Member Username: Maxgain
Post Number: 52 Registered: 3-2007
| Posted on Thursday, February 12, 2009 - 11:39 am: |
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I just went outside and anstalled an 8 foot copper ground rod ( pounded it in 7 and 1/2 feet ) and connected it to the Imax 2000 mounting plate and it made NO DIFFERENCE whatsoever in the amount of general random static recieved. |
Dale
Senior Member Username: Dale
Post Number: 1403 Registered: 12-2002
| Posted on Thursday, February 12, 2009 - 5:29 pm: |
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yea thier just noisy.try a sirio or maco dale/a.k.a.hotrod cef426 cvc#64
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Tech808
Moderator Username: Tech808
Post Number: 16572 Registered: 8-2002
| Posted on Thursday, February 12, 2009 - 6:19 pm: |
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Maxgain, OK you have your antenna grounded to an 8' ground rod. That is good. Your IMAX mounting plate should be grounded to the Mast Pipe. The mast pipe should be grounded to the tower or pole/tower then it should be grounded to the ground rod. Question: Where do you have your: Antenna, Mast/Tower/Pole, Coax, Radio, Meter's grounded to? Remember they "ALL" need to be connected/grounded to the same "SINGLE POINT" GROUND for maximum performance ie: output & receive. Hope this help's, Lon CEF#808~HAM#001/N9CEF CVC#002 Tech808@copperelectronics.com
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Maxgain
Member Username: Maxgain
Post Number: 53 Registered: 3-2007
| Posted on Thursday, February 12, 2009 - 6:37 pm: |
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My antenna is currently mounted ONE foot above the ground on a metal pipe and the ground rod is right next to it. Providing this ground connection, even at this short of a distance has not made any noticable change. I have tried various grounding scenarios, all grounds at the radio end of things to a ground rod right outside the window, tried grounding to water pipes in the house, tried 600 volt heavy guage wire to connect to ground, tried flat copper strip 2' wide to connect to ground,... and NOTHING, I mean NO kind of ground has ever helped improve reception, reduced static, or made a difference in my radios performance, TVI, Transmit signal-strength, NOTHING ever changed !!! I am beginning to think that other than lightning protection, improvements in radio performance by having a good earth-ground is a myth. |
Tech808
Moderator Username: Tech808
Post Number: 16576 Registered: 8-2002
| Posted on Thursday, February 12, 2009 - 7:03 pm: |
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From your post above: My antenna is currently mounted ONE foot above the ground on a metal pipe Do you mean the base/bottom of the IMAX is actually only 1 foot/12 inches off the ground? Lon CEF#808~HAM#001/N9CEF CVC#002 Tech808@copperelectronics.com
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Patzerozero
Senior Member Username: Patzerozero
Post Number: 4495 Registered: 7-2004
| Posted on Thursday, February 12, 2009 - 7:16 pm: |
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as 808 is implying....8 feet of copper pipe just 12 inches away from your antenna, regardless of the fact that the 8 feet of copper is intended to be ground, could cause a multitude of other problems, not the least of which-or even necessarily-could be noise, on 11m. getting back to square one and being more specific is-WHAT KIND OF NOISE? what kind of radio are you using? is there a very high S-unit reading/noise level? or is it just an abundance of SHHHHHHHH-sounding 'white noise' without 'signal strength'? just a lot of SHHHHHHHH with no reading on the S-meter would indicate the radio. if the meter consistantly shows S-5, S-7, S-9 noise level reading, then you have SOMETHING in your house or nearby creating the problem. do you have a mobile in your vehicle? do you have the same problem in the driveway that goes away as you drive away? |
Kryptkeeper
Member Username: Kryptkeeper
Post Number: 61 Registered: 10-2008
| Posted on Thursday, February 12, 2009 - 7:28 pm: |
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I suggest a good reading of Section 800 of the NEC. It covers grounding requirement of communications systems. It stresses that all grounding systems are to be bonded together. One for lightning and fire protecting, secondly for RF grounding. Motorola has a helpful book on lightning and RF grounding but as to transceiver performance, antenna performance or signal gain/loss that is mostly band conditions and ground loops. If you are working the 11M / CB band it is a band filled with over 28 million sales a year of transceivers. That type of band noise you can't get rid of easly. Bigger antenna means more static from weak signals, over modulated signals and over driven signals. You might try a DSP speaker set-up to see if that helps you quiet all the noise on CB. Hope this helps? CEF #1003 CVC #0179 CEFham #293 Glen Smith, KJ4ICB Kryptkeeper
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Maxgain
Member Username: Maxgain
Post Number: 54 Registered: 3-2007
| Posted on Friday, February 13, 2009 - 10:48 am: |
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Yes, my antenna is 12 inches above ground. A lot of hf stations use ground mounted verticals so I mounted mine the same way for now just for convenience sake. With the 8 ft ground rod attached or not has not made ANY difference in transmit signal strength or received noise. I connected and disconnected the ground several times and took note. I can put the same radio in my car with a 6 foot roof mounted antenna parked in my driveway 40 feet from the location of the base antenna and the channels are dead quiet. I know the problem is not 100 million CB sets on the air nor is it internal receiver circuit noise as the S meter will rest at zero when in the car parked in the driveway a short distance away. I have tried both radios in the vehicle out of curiosity and they both indicate the same. The radios used here are the Uniden PC-78-XL and the Galaxy 2547 base. Ive been very happy with both. I've lived in several different locations and always tried to see if grounding the antenna system would make a difference, roof top mounted, 30 foot mast mounted, tree mounted etc...Attaching a ground to a base antenna has never made a difference for me. |
Dale
Senior Member Username: Dale
Post Number: 1409 Registered: 12-2002
| Posted on Friday, February 13, 2009 - 3:12 pm: |
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imho it souinds like either a household item like a pc ,florecent light inside or outside. or maybe a transformer but i think you still pick that up in your mobile thogh.try this seeing that your antenna isnt mounted high try another location.also if ya have or can get one get a walkie talkie walk around with it inside and out. dale/a.k.a.hotrod cef426 cvc#64
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Drzuo
Member Username: Drzuo
Post Number: 80 Registered: 1-2006
| Posted on Friday, February 13, 2009 - 5:28 pm: |
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Some of the problem is that more and more appliances actually transmit trash right on the band.When I built my radio room I ran #6 wire in wall to 3 solid outlet covers with a grade 8 bolt through it. the wire then ties into my breaker box and out to the ground rod. I tied all of my stuff, PC, radios, power supplies etc into it and my noise dropped significantly. Another thing you can do is buy a monster surge protector with clean power. You'll notice they have different stages of filtration. This tells you how many isolated plugs you have. So a stage 1 will isolate your radio stuff from the rest of the house but not each other, where a stage 2 would isolate your shacks PC from the radio..etc....You can also buy (cheaper) individual filter modules that need to be wired into your ac line. They are only a few bucks each, but you must be familiar with electrical wiring. Hope this helps. |
Hotwire
Senior Member Username: Hotwire
Post Number: 2738 Registered: 1-2005
| Posted on Friday, February 13, 2009 - 7:52 pm: |
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A horizontal beam would be the choice for less man made noise. Kenny CEF491 Reading the mail around Indianapolis Indiana!
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Maxgain
Member Username: Maxgain
Post Number: 55 Registered: 3-2007
| Posted on Saturday, February 14, 2009 - 11:27 am: |
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I want to thank everyone for their insight here as to my situation. I must say that grounding a base antenna for petter performance is a complete myth. At least for me. I have tried it many, many times with many different cb base antennas at many different locations with no detectable change in reception or transmition or even SWR. It may offer lightning protection , but that's about all . I am going to stay vertically polarized since 99% of CB is vertical and I do prefer long haul ground wave over skip. Thanks again! |
Slugo4449
Intermediate Member Username: Slugo4449
Post Number: 180 Registered: 7-2004
| Posted on Friday, February 20, 2009 - 12:47 am: |
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The most quiet antenna I have is a full wave loop. 1005/frequency = the length in feet. I feed it horizontal. If you mount it as a delta loop you can also feed it vertical. But vertical picks up more noise. Loops are quiet. Good luck, Marty |