03-07-2001, 09:56 PM
WA2AEH (billg@warwick.net) writes "I am relatively new to the HF bands having just recently upgraded to General from the ranks of technician. I have had my license for 30 + years and operated exclusively on VHF and UHF so therefore, QRN was something only others had to deal with.
Purchasing a used HF rig, I happily started to work all kinds of DX from 160 to 10 meters and was having a ball. Atmospheric QRN levels were usually manageable and sometimes were horrendous but eventually it went away. I live in a very rural area, only (1) power line into the area from the utility in the middle of 50,000 acres of forest.
Anyway, one evening, turning on the rig and tuning to the 160 meter band, I had steady S9 +30 QRN all the way up to 10 meters although not as bad, only S9 + 20! The noise was definitely not atmospheric and had a distinctive 60 hz buzz. I shut the rig off.
Since it was raining heavily, I figured rain had gotten into a pole transformer or a ceramic insulator and, after the rain stopped and the drying out process started the QRN would go away. So I waited and I waited. Two days later, it was still there and I was getting very disappointed not being able to use my rig and new privileges at all. Is this what I am going to have to deal with on HF?
No I was not going to take this sitting down. I called a ham up the street and went over to his house to make sure, it was on his rig too. Sure enough, heavy QRN on his rig also. He did not notice because he did not turn on his rig for a few days. At this point, I broke out my little hand held AM radio to try to find the source of the problem. Approaching any power line in my house made the radio emit very loud QRN. Walking over to the power pole outside my house, made the radio scream with noise. Ah Ha, found it. I took the pole number down and called the utility. Explained who I was and explained their responsibilities to clean up their act as they are not authorized or licensed by the FCC to transmit interfering signals. His reply – Since it is not an emergency and a weekend, he cannot send out or authorize a crew on OT. My reply - well when can you do it. His reply - maybe on Monday. Dejected I hung up the phone. What else could I do?
Unwilling to take no for an answer, I left the house again with my trusty little radio and walked up and down the road. To my amazement, I was getting a strong QRN signal from all the power poles! Did I give the utility the wrong information? Maybe this little radio is too sensitive to this QRN and it is leading me in the wrong direction? I needed an AM radio that was not so sensitive to the QRN and to reduce the signal to a manageable level for a better fix on the QRN source. I needed something that would tune to a higher frequency.
Enter my mobile ICOM-2800 rig with the AM aircraft band. This was good because now I could drive around, the QRN was reduced substantially and it had an antenna on the roof. I was a mobile QRN locator. On 120mhz, the signal level was much lower and immediately revealed the problem was not on the pole I had previously identified. I decided at this point to make a map of the power pole numbers with street names. I drove to each pole, noted the signal strength and pole number then, proceeded to the next pole. One mile away, I am still logging pole numbers and signal strengths and to my amazement, the QRN is getting stronger. Turning onto a small dirt road, with a few homes, revealed some people standing in the street milling around. Not knowing what they were up to, I got out of my Jeep and started to log more pole information. When they saw me doing this, they came over to me and demanded to know what I was doing (glad I wasn't wearing my hard hat). I explained who I was and what I was doing. They thought I was from the utility at first.
Well, these people were already very angry because they could not watch TV, listen to AM/FM broadcast radio, they could not use cell phones, and could not connect to the internet! For the past (2) days. All because of this heavy QRN apparently. They wanted to know what “I” was going to do about it! I explained I had no power to fix it. I could possibly locate the source however.
I asked them to give me a little time to locate the offending power pole. In about 15 minutes, I had an overwhelming S9 +30 signal on my mobile rig right next to an old power pole even on uhf FM! Getting out of my Jeep and using binoculars, revealed a power line had fallen off it’s insulator and was arcing to ground through the wet pole and a metal bracket. Strange, listening very carefully you could not hear any arcing.
How did I solve this problem? I called the police. I knew if the police could not use their car radios in this area it would then become a public safety issue and it would have to be fixed. I also knew the police frequencies in this area are just above 30mhz.
Sure enough, the police arrived about ½ hour later. I asked the officer to call his office and let him know what was happening. He could not due to the QRN. He had to drive out of the area and make the call. Within short order, (2) utility trucks and a supervisor arrived to fix the problem. Not only did they repair the wire, but they replaced the insulator as well. Problem solved, like turning off a switch.
Analyzing this event afterwards led me to believe that the arcing was causing the entire length of power line to radiate like a long wire antenna. Hence the reason why I was getting such strong signals by each pole at quite a distance from the source. Further analysis (measurements)revealed that the arcing source (AKA Feedpoint) was very close the the center of a terminated (2) mile power line. What a dipole! Therefore, be careful, an identified QRN source may not be the true source and may need further investigation.
The point of this long story is you can remedy these types of problems by applying enough pressure to the right people and authorities to solve QRN problems and quite possibly gain the respect and admiration of your neighbors.
Bill Gerhold
WA2AEH"
Purchasing a used HF rig, I happily started to work all kinds of DX from 160 to 10 meters and was having a ball. Atmospheric QRN levels were usually manageable and sometimes were horrendous but eventually it went away. I live in a very rural area, only (1) power line into the area from the utility in the middle of 50,000 acres of forest.
Anyway, one evening, turning on the rig and tuning to the 160 meter band, I had steady S9 +30 QRN all the way up to 10 meters although not as bad, only S9 + 20! The noise was definitely not atmospheric and had a distinctive 60 hz buzz. I shut the rig off.
Since it was raining heavily, I figured rain had gotten into a pole transformer or a ceramic insulator and, after the rain stopped and the drying out process started the QRN would go away. So I waited and I waited. Two days later, it was still there and I was getting very disappointed not being able to use my rig and new privileges at all. Is this what I am going to have to deal with on HF?
No I was not going to take this sitting down. I called a ham up the street and went over to his house to make sure, it was on his rig too. Sure enough, heavy QRN on his rig also. He did not notice because he did not turn on his rig for a few days. At this point, I broke out my little hand held AM radio to try to find the source of the problem. Approaching any power line in my house made the radio emit very loud QRN. Walking over to the power pole outside my house, made the radio scream with noise. Ah Ha, found it. I took the pole number down and called the utility. Explained who I was and explained their responsibilities to clean up their act as they are not authorized or licensed by the FCC to transmit interfering signals. His reply – Since it is not an emergency and a weekend, he cannot send out or authorize a crew on OT. My reply - well when can you do it. His reply - maybe on Monday. Dejected I hung up the phone. What else could I do?
Unwilling to take no for an answer, I left the house again with my trusty little radio and walked up and down the road. To my amazement, I was getting a strong QRN signal from all the power poles! Did I give the utility the wrong information? Maybe this little radio is too sensitive to this QRN and it is leading me in the wrong direction? I needed an AM radio that was not so sensitive to the QRN and to reduce the signal to a manageable level for a better fix on the QRN source. I needed something that would tune to a higher frequency.
Enter my mobile ICOM-2800 rig with the AM aircraft band. This was good because now I could drive around, the QRN was reduced substantially and it had an antenna on the roof. I was a mobile QRN locator. On 120mhz, the signal level was much lower and immediately revealed the problem was not on the pole I had previously identified. I decided at this point to make a map of the power pole numbers with street names. I drove to each pole, noted the signal strength and pole number then, proceeded to the next pole. One mile away, I am still logging pole numbers and signal strengths and to my amazement, the QRN is getting stronger. Turning onto a small dirt road, with a few homes, revealed some people standing in the street milling around. Not knowing what they were up to, I got out of my Jeep and started to log more pole information. When they saw me doing this, they came over to me and demanded to know what I was doing (glad I wasn't wearing my hard hat). I explained who I was and what I was doing. They thought I was from the utility at first.
Well, these people were already very angry because they could not watch TV, listen to AM/FM broadcast radio, they could not use cell phones, and could not connect to the internet! For the past (2) days. All because of this heavy QRN apparently. They wanted to know what “I” was going to do about it! I explained I had no power to fix it. I could possibly locate the source however.
I asked them to give me a little time to locate the offending power pole. In about 15 minutes, I had an overwhelming S9 +30 signal on my mobile rig right next to an old power pole even on uhf FM! Getting out of my Jeep and using binoculars, revealed a power line had fallen off it’s insulator and was arcing to ground through the wet pole and a metal bracket. Strange, listening very carefully you could not hear any arcing.
How did I solve this problem? I called the police. I knew if the police could not use their car radios in this area it would then become a public safety issue and it would have to be fixed. I also knew the police frequencies in this area are just above 30mhz.
Sure enough, the police arrived about ½ hour later. I asked the officer to call his office and let him know what was happening. He could not due to the QRN. He had to drive out of the area and make the call. Within short order, (2) utility trucks and a supervisor arrived to fix the problem. Not only did they repair the wire, but they replaced the insulator as well. Problem solved, like turning off a switch.
Analyzing this event afterwards led me to believe that the arcing was causing the entire length of power line to radiate like a long wire antenna. Hence the reason why I was getting such strong signals by each pole at quite a distance from the source. Further analysis (measurements)revealed that the arcing source (AKA Feedpoint) was very close the the center of a terminated (2) mile power line. What a dipole! Therefore, be careful, an identified QRN source may not be the true source and may need further investigation.
The point of this long story is you can remedy these types of problems by applying enough pressure to the right people and authorities to solve QRN problems and quite possibly gain the respect and admiration of your neighbors.
Bill Gerhold
WA2AEH"