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Message |
    
1861
Junior Member
Username: 1861
Post Number: 33
Registered: 2-2004
| | Posted on Wednesday, January 12, 2005 - 12:26 pm: | 
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IF I RUN MY RADIO IN MY RADIO ROOM , I COME THROUGH SPEAKER IN TV AND RADIO IN A COUPLE ROOMS IN HOUSE . IF I RUN POWER , IT GETS A LITTLE LOUDER . I HAVE EVERYTHING GROUNDED WELL , AND RUNNING TWO GOOD LOW PASS FILTERS . IF I MOVE RADIO SET UP INTO ANOTHER ROOM , NO INTERFERENCE . I WANT TO USE RADIO ROOM ! ANY IDEA HOW I CAN KEEP RF FROM GETTING INTO THE ELECTRICAL WIRES WITHOUT MOVING RADIO ? |
Bruce
Senior Member
Username: Bruce
Post Number: 2078
Registered: 9-2003
| | Posted on Wednesday, January 12, 2005 - 2:37 pm: |
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where is your antenna? |
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 338
Registered: 7-2004
| | Posted on Wednesday, January 12, 2005 - 4:45 pm: |
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my neighbor had 50' piece of readymade radioshack rg8 with a 29classic & elcheapo 2 trans amp. tvi in his house was BAD. nobody else complained, but don't know. with MUCH persuasion, invested in 50' piece of double shielded 9913 and had ********** install silver teflon ends. tvi in his house-GONE.
BTW-no filters are being used. |
1861
Junior Member
Username: 1861
Post Number: 34
Registered: 2-2004
| | Posted on Wednesday, January 12, 2005 - 7:41 pm: |
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WHERE COULD I GET THE DOUBLE SHIELDED 9913 ? |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 134
Registered: 9-2004
| | Posted on Wednesday, January 12, 2005 - 9:56 pm: |
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you can get it from RF parts company. what do you mean when you say everything is grounded well. most of the time its not feasable to run a graound rod to two separate rooms in the house. give us some details of your setup, radio, amp, antenna, house or apt. etc... |
1861
Junior Member
Username: 1861
Post Number: 36
Registered: 2-2004
| | Posted on Wednesday, January 12, 2005 - 10:51 pm: |
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okay , my radio room is a small room i built in back of garage . I HAVE A 8 FT GROUND ROD DRIVEN WITH ALL EQUIPMENT GROUNDED TO IT , ONLY ABOUT A 2 1/2 FT RUN FROM EQUIPMENT . ANTENNA (IMAX 2000 ) ON TRIPOD ON TOP OF HOUSE ABOUT 30 FT FROM GROUND . GROUNDED TO GROUND ROD ON OPPOSITE SIDE OF HOUSE FROM RADIO ROOM 70FT RG8U COAX . VECTRONICS LP FILTER BEHIND RADIO AND RF 2000 LP BEHIND MAVERICK 250 AMP . I CAN MOVE ENTIRE UNIT INTO MY COMPUTER ROOM WITH NO GROUNDING AND NO RF ON TV WHICH IS IN NEXT ROOM I AM DK AT 2 WATTS . I TURNED MIC GAIN DOWN TO 10 AND IT HELPED BUT DIDN,T ELIMINATE . JUST CAN,T FIGURE OUT WHY IT DOES IT IN MY ROOM IN GARAGE AND NOT IN HOUSE . |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 139
Registered: 9-2004
| | Posted on Thursday, January 13, 2005 - 4:55 pm: |
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lets try some troubleshooting. first, hook up the equipment in the radio room. plug everything into the wall, but dont connect anything to the ground rod. what does the interference look like now? hook up the ground rod; any change? leave it hooked up the way that produced less interference. now go to the antenna and remove the ground wire from the tripod base or wherever its hooked to so that the ground rod is not connected. note the difference in the interference. if doing any of this has eliminated the interference then you've found the problem. most likely you have a ground loop happening and the culprit is not your radio, but the house's electrical system. you might have to find out where your house is grounded and add another ground rod. otherwise, suspect things like, the cable for the TV's running through the garage. the coax on the roof running near the TV antenna or cables. and other stuff like that.
hope this helps. post the results of your tests.
matt |
1861
Junior Member
Username: 1861
Post Number: 37
Registered: 2-2004
| | Posted on Thursday, January 13, 2005 - 8:21 pm: |
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THANKS KID , I,LL TRY UNHOOKING THE GROUND TO ANTENNA . IT ISN,T COMING THROUGH CABLE COAX , BECAUSE I HAVE DISCONNEDTED CABLE AND IT STILL COMES THROUGH . I KNOW SOMEHOW IT IS GETTING INTO ELECTRIC WIRES --- JUST DON,T KNOW HOW , OR HOW TO STOP IT |
Chad
Member
Username: Chad
Post Number: 81
Registered: 11-2004
| | Posted on Thursday, January 13, 2005 - 9:39 pm: |
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Kid nailed it,
The neutral in your home is bonded to the ground. How old is your home? How old is your electrical? Keep in mind that your radio ground on an older home may be your WHOLE HOUSE ground if the original had rotted away, or in worst case, is non existant. Sometimes a load test on your panel grounding can tell you alot.
When I was a kid my parent's service was grounded to the main water line. They came along and put in new (plastic) meters. I discovered this when (after a fault) I stepped onto the drain while taking a shower (that dirty, soapy water sure is inoized!). The whole damn house was floating up in voltage!
People over look this, it's worth a check!
Tour busses,rainy nights, and undgrounded generators, oh my...
Chad |
1861
Junior Member
Username: 1861
Post Number: 38
Registered: 2-2004
| | Posted on Friday, January 14, 2005 - 9:59 am: |
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OKAY , NEED MORE SUGGESTIONS . I UNHOOKED GROUND FROM ANTENNA , RF GOT LOUDER -- HOOKED IT BACK UP AND UNHOOKED GROUND FROM EQUIPMENT , GOT LOUDER -- UNHOOKED BOTH , GOT MUCH LOUDER . HOOKED EVERYTHING BACK UP , BACK TO NORMAL , RF1 LOW , BUT STILL THERE . WHERE SHOULD I GO FROM HERE ? |
Pig040
Advanced Member
Username: Pig040
Post Number: 640
Registered: 7-2003
| | Posted on Friday, January 14, 2005 - 11:31 am: |
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I would run a dedicated power line to the radio room, that helped solve my tvi problem once.
Rich |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 142
Registered: 9-2004
| | Posted on Saturday, January 15, 2005 - 7:59 pm: |
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you said this is a radio room you built in the garage. where are you drawing power from? is it an extention cord, or did you add outlets in the radio room? also check the breaker panel. is the circuit for the garage on a different breaker than the room by the offending tv? have you found the ground connection for the house electrical system yet? |
1861
Junior Member
Username: 1861
Post Number: 39
Registered: 2-2004
| | Posted on Saturday, January 15, 2005 - 10:30 pm: |
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THE GARAGE ALLREADY HAD OUTLETS . THEY ARE ON DIFFERENT CIRCUIT . YES , I FOUND THE HOUSE GROUND , RIGHT BELOW METER , AND JUST OUTSIDE FROM BREAKER BOXES I JUST GOT MY 139XLR BACK FROM TUNNING AND CHANNEL MODS . IT ONLY SWINGS ABOUT 12 FROM 4 DK . IF I DON,T RUN AMP , IT DOESN,T COME IN ON TV . |
Radioman123
Junior Member
Username: Radioman123
Post Number: 11
Registered: 12-2004
| | Posted on Saturday, January 15, 2005 - 11:26 pm: |
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I'd be curious to know if it comes thru the television with the tv "off". Also if it's actually radiated rf coming from the antenna there may not be too much you can do. Years ago there were tv's with well grounded tuners and such, but then came making things cheaper and cheaper......Good luck |
Sg569
Junior Member
Username: Sg569
Post Number: 49
Registered: 12-2004
| | Posted on Thursday, January 20, 2005 - 9:04 pm: |
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Yea, Years ago couldn't keep good enough parts in stock, now, can't keep CHEAP enough parts in stock, thats in the auto parts biz.
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Supertech1
Junior Member
Username: Supertech1
Post Number: 11
Registered: 1-2005
| | Posted on Thursday, January 20, 2005 - 10:24 pm: |
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try putting rfi snap-on chokes on the ac wiring(power cords) for t.v., radio etc. and also powersupply you run in radio room. also try running a seperate ground source to you radio room ac power plug--if possible. then try isolation transformer that should about eliminate any ac-rf bleed back problem. next thing is coil your coax 4-5 turns 6-8" dia. tie wrap the hoop behind radio or bottom of anteena mast. check to make sure you are not running your coax parallel to ANY a.c. wiring too, reroute if nessesary. and good luck. if all else fails, buy better t.v. w/ better rejection or subscribe to cable/satellite t.v. |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 157
Registered: 9-2004
| | Posted on Thursday, January 20, 2005 - 11:47 pm: |
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1861, i agree with all of supertech's suggestions.
i was just reading some old posts and i ran across one where you were asking about interference from an amp. in this post you said that you had your coax going from the imax to a barrel connector that was grounded to an 8ft. ground rod. if you are still set up like this then i have a pretty good idea of where your interference is coming from. you are leaking RF from that barrel connector. i'll bet you are very proud of your invention, but, im sorry, you must remove it. dont even bother doing any of the things suggested here until you do this. DO NOT DISREGARD THIS AS THE SOURCE OF YOUR PROBLEM! 99% sure this is it! you need to get some BIG copper braid about 1 1/2" in width. bolt one end to the lowest point of your antenna mast system. and run it, (no kinks), directly to that ground rod which should be driven to 1 foot below the surface of the earth. run your coax directly ( no splices or barrel connectors) to the low pass filter. then attatch copper braid to each piece of equip. and attatch the other ends along a piece of copper pipe that runs along the back of your radio desk. use the BIG copper braid to attatch the copper pipe to A DIFFERENT 8ft. ground rod. this ground rod should be as far from the antenna ground rod as possible. (at least 8ft.)
if you are not going to do this; you might as well stop asking for help because nothing else is going to work until you get your gear set up this way. TRY IT, YOU'LL LIKE IT!!!
matt |
Chad
Member
Username: Chad
Post Number: 93
Registered: 11-2004
| | Posted on Friday, January 21, 2005 - 9:25 am: |
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Leaking RF from a barrel connnector? (EDIT) Would a polyphaser constitute as a barrel connector?
Now if the barrel connector had a significant amount of oxidation I could see problems, but chances are the barrel connector has no openings and would be a 100% sheild.
I have a similar arrangement, the barrel is brazed to the rod, via an eyelet and then wrapped in cold shrink, this in turn is covered with a flower pot for trip hazard safety and protection from the elements. Even though everything in the shack is grounded to that rod, lifitng this conection causes MORE interference. Granted my only interference is with cheapo computer speakers and this was ratified bu bonding the ground on the computer soundcards to the case ground.
Chad
Tech 833 adds- A barrel connector DOES have a small amount of loss, and it is not a 100% pure shield. Unless, you soldered the connectors together. Threaded connections are not 100% in RF terms. A Polyphaser is not just a barrel, there is a lot going on in there. 0.5 dB loss is the rated insertion loss of a Polyphaser. I have measured them and found that number to be a little high. |
1861
Junior Member
Username: 1861
Post Number: 40
Registered: 2-2004
| | Posted on Friday, January 21, 2005 - 9:45 am: |
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KID , I ALLREADY GOT RID OF BARREL CONNECTOR -- JUST TRIED IT BECAUSE IT WAS SUGGESTED AS A POSSIBLE CURE . I HAVE THE RFI DOWN ENOUGH I GUESS I CAN LIVE WITH IT UNTILL SPRING THAW , THEN I AM GOING TO RAISE ANTENNA ANOTHER 10 FT. AND GET THE 9913 DOUBLE SHIELD COAX AS PATZERRO SUGGESTED THANKS |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 159
Registered: 9-2004
| | Posted on Saturday, January 22, 2005 - 9:01 pm: |
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right on, i didnt check the date of the post that i referenced but i thought id mention it just in case. glad to hear you got rid of it. not to get off subject but do you have a ground plane kit on the antenna?
matt |
Patzerozero
Intermediate Member
Username: Patzerozero
Post Number: 344
Registered: 7-2004
| | Posted on Sunday, January 23, 2005 - 8:32 pm: |
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my island, not being a tropical paradise this weekend, but taking a direct hit from this little blizzard saw my maco v5/8, still standing tall(well 15' to feedpoint tall) and well encrusted in snow & ice, with the radials currently resting on my roof under 3+ feet of drift, swr's under 2:1 nonetheless. thru the ole 2' tall midland no-ground plane fiberglass ant out the door & left it in a snowdrift. swr's 2.5:1 on grant lt & 2-454 amp, kids screaming they couldn't see video games thru tvi. had a 15' piece of 9913 so i soldered a sil/tef 259 on each end & thru antenna back in snowdrift that grew a foot in 30 minutes...
swr's still 2.5:1, and ALL of the tvi disappeared.
i used to only use EXPENSIVE coax in the HP mobile installations & listen to everybody say it was a waste of $$ as losses weren't noticeable, and as someone who talks so infrequently on the base never paid much attention to rfi problems. i must be getting too old to sit on the beach in minus 30 degree windchills to talk on the radio & find myself in the shack a bit more often then before. my bases' rf grounding consists of a wire from ALL radio, amp, meter, switches, power supplies etc going less then 4' for the longest to a flattened piece of copper pipe, 1' long then to a piece of bare #6 copper wire just less then 8' long to a 5/8" x 8' ground rod sunk to ground level, with my coax's shield bared & clamped to ground rod, everything liberally coated with noalox and/or penetrox and then covered with liquid electrical tape. base is a real base-as in BASEment...rfi/tvi w/ that system is 'very few complaints', and i have seen rfi in mobile eliminated with use of EXPENSIVE coax, and even now in base with my toy antenna.
let's see now, taking a look @ 1861's profile, probably has about $500 invested in base setup, even the cheapest base setup, without an amp has to be $200, with 10x that probably being what a fair amount of base stations having invested in them, WHY would you use a $25 piece of ready made radio shack coax(cut a piece open-it's shield % can't be more then 75%, no matter what they claim, & as for what's on their mag mounts' rg58, cut one of them open too! are there even 15 strands of wire wrapped around the toilet paper insulation??shield-that shield ain't keeping NO rf from straying!) anyway, spend the 60cents a foot for not just good stuff, but the BEST you can get-HIGHEST shield % and LOWEST loss. some is SO LOW they don't even rate it under 50 mhz, and go for the pl259 by amphenol at least, silver/teflon made in usa at least or amphenol when you can find 'em, & if YOU can't solder 'em yourself, get 'em from a place that will solder 'em (if you can't find a place, e-mail me, there is a place i've been using for 20 years to get my coax & connectors, & they solder on the ends, too.)about $50 for a 75' piece w/2-sil/tef pl259's, not too much to spend, and i HAVE seen the difference. |
1861
Junior Member
Username: 1861
Post Number: 42
Registered: 2-2004
| | Posted on Sunday, January 23, 2005 - 9:48 pm: |
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PATZEROZERO , I AM ORDERING THE COAX AND PUTTING IT BACK UP AS SOON AS SPRING THAW ARRIVES . I UPDATED MY PROFILE , AND YOU ARE RIGHT , I HAVE MUCH OVER 500 IN MY BASE , AND SHOULD AND WILL UPGRADE TO BEST COAX I CAN GET . WE HAVE ABOUT 5 FT. SNOW ON GROUND HERE IN THE MOUNTAINS , SO IT WILL HAVE TO WAIT A LITTLE WHILE |
Kid_vicious
Intermediate Member
Username: Kid_vicious
Post Number: 166
Registered: 9-2004
| | Posted on Sunday, January 23, 2005 - 10:10 pm: |
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why doesnt copper carry 9913? i would buy it from them if they did. here, here! to using the best coax possible.
matt |
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