Author |
Message |
Road_warrior
Senior Member Username: Road_warrior
Post Number: 1163 Registered: 7-2004
| Posted on Tuesday, January 17, 2006 - 1:04 pm: |
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Heres my problem: When i hook a station ground up i cause TVI/RFI problems. NO STATION GROUND hooked up, i have NO problems what-so-ever. Even running high wattage outputs. I work closely with my neighbors and they work with me. I run a RCI 2995dx/ TVI filter mounted directly into radio, coax plugs into filter. No other equipment in-line. The length of copper wire i need to go from radio to outside groundrod is 7 1/2 feet. I have tried large solid copper wire, braided wire, 2 inch copper strap. When i hook it up i have problems. Unhook and totally remove wire. ZIP O...No problems! Any suggestions to why this is happening??? Thank You! |
Marconi
Advanced Member Username: Marconi
Post Number: 528 Registered: 11-2001
| Posted on Tuesday, January 17, 2006 - 5:03 pm: |
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I don't understand what is causing the problem, but appears you have ground loops working. I would leave the ground off. Ground the antenna support to its own system, but forget the RF ground or additional ground to the station. Disconnect during bad weather and connect coax directly to this ground system outside of the house just in case. That is the only time I would maybe use the ground you are talking about. |
Marconi
Advanced Member Username: Marconi
Post Number: 532 Registered: 11-2001
| Posted on Tuesday, January 17, 2006 - 5:54 pm: |
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I look at antennas this way. We try to provide all we need physically for the antenna to work on the antenna itself including often a ground plane. This is so we can get it high up in the air where it can do some good. Reason we do this is because the ground side of an antenna can and very often is involved with losses and most often these can be considerable. Losses just plain sound bad to me considering we talking about an antenna. Often losses have an affect of making thing even look better in a kind of weird sort of way. So, in my case I try my best to avoid grounds except for the purposes of safety. Some notable experts even go so far as to claim that most antennas do not need grounding, that is in the sense we typically speak about that subject in this type of setting. I am sure I will get some arguments here, but that is just what makes the world go around. Just my thoughts. |
Road_warrior
Senior Member Username: Road_warrior
Post Number: 1164 Registered: 7-2004
| Posted on Tuesday, January 17, 2006 - 6:19 pm: |
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Yeah, i don't know what to think. I can't get the radio any closer to try a shorter ground wire. I have aluminum siding and ground wire runs about 2 inches beneath it to rod. Wonder if RF is coupling to siding or something??? I don't know. |
Rldrake
Junior Member Username: Rldrake
Post Number: 28 Registered: 1-2006
| Posted on Wednesday, January 18, 2006 - 1:05 am: |
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Road, what is your "station" ground for? What is it that that you are trying to do with this "station" ground. There are 3 types of grounds. Electrical safety (mains). RF ground. Lightening ground (static). What type of ground are you attempting and for what reason? |
Road_warrior
Senior Member Username: Road_warrior
Post Number: 1166 Registered: 7-2004
| Posted on Wednesday, January 18, 2006 - 9:02 am: |
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I have my lightning protection ground and Electrical safety grounds hooked up. No problems there. Just trying to hook up my cb equipment RF ground. Ground wire/strap from radio to ground-rod. Groundrod is tied in with the other systems. Using a polyphaser and need to complete my RF equipment grounding system. Like i said, without rf ground i have no problems. |
Hollowpoint445
Senior Member Username: Hollowpoint445
Post Number: 1021 Registered: 6-2004
| Posted on Wednesday, January 18, 2006 - 11:49 am: |
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I think that presently your coax's shield is acting as your station ground and apparently doing a good job. The ground strap you're using for a station ground needs to be significantly larger in surface area than the shield of your coax so it will act as the RF ground. If it is not significantly larger, adding a ground wire can tune your coax shield to resonance and it can radiate RF. I think that is what's happening to you. You can wrap a choke in your coax so it won't act as the RF ground, but since it's working why not just use it as is? |
Road_warrior
Senior Member Username: Road_warrior
Post Number: 1168 Registered: 7-2004
| Posted on Wednesday, January 18, 2006 - 6:12 pm: |
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That makes sense Hollowpoint. |