HELP...RFI PROBLEMS!!

[highdrive]

Ok, had problems with my dipole messing up tv's in the house...and at my neighbors house. He even complained that his garage door would open when I key up with power! I just installed a m103 and installed new coax. Swr's are real low (1.1 with radio only). Now the interference is worse, I'm doing more damage barefoot. I have a 7 turn coax balun feeding into the gamma to try and keep rf from feeding down the shield. My ground could prob be upgraded...but will more ground cure the problem? I'm only 30ft up...and can't get any higher without a bigger tower.

[drdx]

Sounds like, other than height, which is not terrible, you have your bases covered. How about a Low pass filter? Maybe the door opener is on a multiple of this band frequency wise, and you're radiating some harmonics, triggering it. If you're barefoot and it still does it, I wouldn't think it is interference of the RF overload variety, but more frequency related, and something filtering could cure. Can you turn the beam and reduce it any? Where did you get the figures for your beam, as far as the element lengths and spacing? That may not matter here, but if you can make it more directional via better antenna measurements, it may allow you to use it more, just not in his direction. -drdx

[Midlander]

Try using a different power outlet in the house, try a different radio. Put some ferrite beads on your power wires. I found that my beam would cause problems with electronics under the antenna, but objects that are further out were fine.

You may also have to place the antenna in a different location, and see what happens.

are you having any interference in your own house?

Hope you can solve the problems. I've been there before. Good luck.

[Red Warrior]

Sounds like your balun could use some work, The number of turns is not critical but the length of coax used is. Start with 18 feet of RG8X (or RG213 if you are running over 1000 watts). Wind the coax over a form made from 4" diameter PVC pipe. Keep the windings from overlapping each other.

When you install the balun, keep it away from metal. Install it as close to the M103 feed as possible but use standoffs to keep it away from the mast or boom.

I have a M103 at 30 feet and I run over 1000 watts. My closest neighbor is 28 feet from the end of my beam and she experiences no RFI.

[Midlander]

Sounds like your balun could use some work, The number of turns is not critical but the length of coax used is. Start with 18 feet of RG8X (or RG213 if you are running over 1000 watts). Wind the coax over a form made from 4" diameter PVC pipe. Keep the windings from overlapping each other.

When you install the balun, keep it away from metal. Install it as close to the M103 feed as possible but use standoffs to keep it away from the mast or boom.

I have a M103 at 30 feet and I run over 1000 watts. My closest neighbor is 28 feet from the end of my beam and she experiences no RFI.

The number of turns in the balun dictates the length of coax cable used to make the balun... He already has a balun and it's not working, so he will need to try other things.

[Red Warrior]

Sounds like your balun could use some work, The number of turns is not critical but the length of coax used is. Start with 18 feet of RG8X (or RG213 if you are running over 1000 watts). Wind the coax over a form made from 4" diameter PVC pipe. Keep the windings from overlapping each other.

When you install the balun, keep it away from metal. Install it as close to the M103 feed as possible but use standoffs to keep it away from the mast or boom.

I have a M103 at 30 feet and I run over 1000 watts. My closest neighbor is 28 feet from the end of my beam and she experiences no RFI.

The number of turns in the balun dictates the length of coax cable used to make the balun... He already has a balun and it's not working, so he will need to try other things.

Reference [Please login or register to view this link]. I quote "The number of turns is not critical because the inductance depends more on the length of the wire (coax) than on the number of turns, which will vary depending on the diameter of the plastic pipe that is used."

[lonesome 500]

18 to 21 feet on 4" pvc........just behind the watt meter inside the house WITH a low pass filter ...........killed it all for a local in a subdivision here

PS....KEEP YOUR MODULATION BELOW 100 PERCENT......which may be impossible if you have a hacked up radio

[Circuit Breaker]

Grounding isn't an issue because all grounding would do is get you a DC ground...which will do nothing to reduce RF interference. For that, you would need a good RF ground and they are very difficult to achieve due to soil conditions.

[lonesome 500]

Grounding isn't an issue because all grounding would do is get you a DC ground...which will do nothing to reduce RF interference. For that, you would need a good RF ground and they are very difficult to achieve due to soil conditions.

not always the rule............dc grounding will have an affect on rf

rf is current too

[drdr]

Lonesome- You have the balun in your house. I always heard that it was supposed to be as close as possible to the antenna. Glad to know that it works. I'm getting ready to set a new antenna (maco v58) and was wondering where to mount with the balun. I have the low pass filter in line already.

[lonesome 500]

helped one of my locals built that....as i don't have the rfi troubles [thank goodness]

with the antenna [a99] already in the air....@85' it was impossible to put at the ant....besides breaking the feedline run and use of a pl258 just isn't my bag....so

we did some pretty evasive testing....and found that if it is the last thing in line....just before leaving the shack and as low to the floor as possible

it works

he bled on....neighbors phones....answering machines....and stereos within 1 block

this killed it