Hi,
Probably 10 years ago, I installed a longwire antenna on my house's detached garage. One end of the longwire is connected to a "magnetic balun" transformer. From there, a coax crosses over the driveway and enters in through the wall of the house. The antenna was grounded with two ground rods: one at the end of the wire and the other at the balun transformer. The antenna worked OK but I wasn't thrilled with its noise rejection qualities. I still seemed to pick up quite a bit of indoor RFI. Perhaps now at last I know why...
A few weeks ago, I discovered a ground loop issue with my broadband Internet connection. In an attempt to resolve the issue, I had an electrician install a new cold water pipe ground and bond it to the power company's ground rod outside. Even with this work done, I still had a bad ground loop whenever I connected the cable modem to a grounded AC outlet and the ISP's coax outlet. A ground loop isolator on the coax got rid of most of the hum but I was still left with high-intensity EMF radiation that caused me acute physical discomfort. I finally managed to hook up the cable modem to an ungrounded AC outlet and with a plain coax--no ground loop eliminator--with a blessed reduction in EMF radiation! Note that the cable Internet's ground is bounded to the house electric ground as is my landline phone.
So far so good, BUT I have observed with the help of an EMF meter that the new cold water ground is emitting high EMF radiation (>= 50 milligauss versus my house's overall 1.5 milligauss reading) even when the main breaker is turned off. Frankly, this has me a bit mystified, but it's gotten me to think about my longwire antenna. I now realize that I set it up wrong insofar as the grounding is concerned. I think what ought to be done is to bond the antenna's grounds to the house ground. The antenna being atop a detached garage, how to do this isn't obvious to me. The only thing I know for sure is that I ought to add a ground wire between the antenna's two grounds then somehow bond this ground to the house ground. Correct?
My questions:
1. What's the simplest way to bond the antenna's two grounds to the house ground: attach a ground wire around the existing coax, bond the antenna ground to the coax shield and add a ground block from the coax to the house ground, or what???
2. Is there any possible way that my antenna with its current independent grounds might be causing a differential (aka ground loop) with my house ground due to their being located 20-30' distant and not being bonded to house ground?
Many thanks!
Dave
Probably 10 years ago, I installed a longwire antenna on my house's detached garage. One end of the longwire is connected to a "magnetic balun" transformer. From there, a coax crosses over the driveway and enters in through the wall of the house. The antenna was grounded with two ground rods: one at the end of the wire and the other at the balun transformer. The antenna worked OK but I wasn't thrilled with its noise rejection qualities. I still seemed to pick up quite a bit of indoor RFI. Perhaps now at last I know why...
A few weeks ago, I discovered a ground loop issue with my broadband Internet connection. In an attempt to resolve the issue, I had an electrician install a new cold water pipe ground and bond it to the power company's ground rod outside. Even with this work done, I still had a bad ground loop whenever I connected the cable modem to a grounded AC outlet and the ISP's coax outlet. A ground loop isolator on the coax got rid of most of the hum but I was still left with high-intensity EMF radiation that caused me acute physical discomfort. I finally managed to hook up the cable modem to an ungrounded AC outlet and with a plain coax--no ground loop eliminator--with a blessed reduction in EMF radiation! Note that the cable Internet's ground is bounded to the house electric ground as is my landline phone.
So far so good, BUT I have observed with the help of an EMF meter that the new cold water ground is emitting high EMF radiation (>= 50 milligauss versus my house's overall 1.5 milligauss reading) even when the main breaker is turned off. Frankly, this has me a bit mystified, but it's gotten me to think about my longwire antenna. I now realize that I set it up wrong insofar as the grounding is concerned. I think what ought to be done is to bond the antenna's grounds to the house ground. The antenna being atop a detached garage, how to do this isn't obvious to me. The only thing I know for sure is that I ought to add a ground wire between the antenna's two grounds then somehow bond this ground to the house ground. Correct?
My questions:
1. What's the simplest way to bond the antenna's two grounds to the house ground: attach a ground wire around the existing coax, bond the antenna ground to the coax shield and add a ground block from the coax to the house ground, or what???
2. Is there any possible way that my antenna with its current independent grounds might be causing a differential (aka ground loop) with my house ground due to their being located 20-30' distant and not being bonded to house ground?
Many thanks!
Dave