K3UD
08-17-2003, 09:29 PM
Cape Girardeau, MO is listed as one of the test sites for BPL.
On Saturday, August 16, I made the trip to Cape Girardeau and spent about an hour in the BPL test area which is located between Lexington Avenue and Business route 55 in a subdivision along Rampart, Melrose, Carolina, Belleridge, Magnolia and Kurre streets. I also worked my way around other areas of the city to see if BPL interference showed up anywhere else. I did not find any, other than at the test site.
I used an Icom 737 and a Hustler antenna on a 2001Chevy Astro van, and had #the 75, 40, and 20 meter resonators available. I found and monitored interference on those bands. This was filmed with a borrowed 8mm camcorder and am sending the tape to Ed Hare, W1RFI, at the ARRL. The tape clearly shows S-meter readings of the interference reaching as high as 35 over S-9 and recorded the audio. prior to entering the test area,The Icom 737 was tuned to a net on 7.277 where all of the stations were good copy. I entered the test area at 12:35 PM CDT.
Here is a brief synopsis of what I saw and heard.
1. The main area of the interference was at the intersection of Melrose, Rampart, and Kurre avenue. Once there, the interference was easily recognizable.
2. The BPL interference emanating from the above mentioned intersection could be clearly heard at S-9 or better levels in excess of 500 feet and was still audible at over 1000 feet affecting reception on the other streets mentioned.
3. The interference had the same characteristics that showed up on W1RFI’s test, with one difference. It seemed that when I was stationary, the interference would go from 20+ over S-9 down to S-9 or less and then back up. It almost seemed like there was an "idle mode" and an "active mode".
4. Interference was the worst on 20 meters reaching 35 over
S-9 and the least on 75 meters where it reached about 5 over
S-9. My noise blanker which is great at taking out considerable ignition noise had no effect. A very active Geiger Counter is a good description of what the interference sounded like.
5. I saw only 2 inductive couplers on power poles. Both my wife and I were looking for them. I have them on the tape. Both were on poles at the above mentioned intersection.
6. It seemed that the interference hacked up the upper part of the AM broadcast band, however, there seemed to be a high level of power line noise all over the city, (at least what I took to be power line noise) and this could have been what I was hearing.
There was one odd effect. Cape Girardeau has an AM station at 1550 kHz and in the test area, I was getting images of the station all they was from 1710 down #to 1600 kHz and again at 1520 kHz. Since I did not know where the station was located, I suspected that I was quite close to it and getting overload. However, when I left the test area, the images faded in about 1/2 mile.
7. I think I heard effects in the lower part of the FM broadcast band. #I was receiving audio from a TV channel 6 transmitter at the low end, and it definitely had some kind of interference on it that could also be heard to some extent on clear channels up the band. Again this could be regular power line noise.
8. It also seemed that the test area was extremely limited in scope being confined to the streets mentioned above as interference levels dropped on adjacent streets in the subdivision. However, I was using a Hustler, which is not the most efficient mobile antenna. I suspect that anyone using typical HF antennas at a fixed location anywhere in the subdivision would have a serious interference problem.
This was not a series of scientific measurements and no claim is being made for such. Rather it was just me, an average ham operator making a field trip to a test site wanting to hear for myself what BPL interference sounded like and if it is a bad as it is made out to be. In my opinion, it is every bit as bad and I can see where it has the potential to change ham radio as we know it and turn HF into a wasteland wherever it is deployed.
73
George
K3UD
On Saturday, August 16, I made the trip to Cape Girardeau and spent about an hour in the BPL test area which is located between Lexington Avenue and Business route 55 in a subdivision along Rampart, Melrose, Carolina, Belleridge, Magnolia and Kurre streets. I also worked my way around other areas of the city to see if BPL interference showed up anywhere else. I did not find any, other than at the test site.
I used an Icom 737 and a Hustler antenna on a 2001Chevy Astro van, and had #the 75, 40, and 20 meter resonators available. I found and monitored interference on those bands. This was filmed with a borrowed 8mm camcorder and am sending the tape to Ed Hare, W1RFI, at the ARRL. The tape clearly shows S-meter readings of the interference reaching as high as 35 over S-9 and recorded the audio. prior to entering the test area,The Icom 737 was tuned to a net on 7.277 where all of the stations were good copy. I entered the test area at 12:35 PM CDT.
Here is a brief synopsis of what I saw and heard.
1. The main area of the interference was at the intersection of Melrose, Rampart, and Kurre avenue. Once there, the interference was easily recognizable.
2. The BPL interference emanating from the above mentioned intersection could be clearly heard at S-9 or better levels in excess of 500 feet and was still audible at over 1000 feet affecting reception on the other streets mentioned.
3. The interference had the same characteristics that showed up on W1RFI’s test, with one difference. It seemed that when I was stationary, the interference would go from 20+ over S-9 down to S-9 or less and then back up. It almost seemed like there was an "idle mode" and an "active mode".
4. Interference was the worst on 20 meters reaching 35 over
S-9 and the least on 75 meters where it reached about 5 over
S-9. My noise blanker which is great at taking out considerable ignition noise had no effect. A very active Geiger Counter is a good description of what the interference sounded like.
5. I saw only 2 inductive couplers on power poles. Both my wife and I were looking for them. I have them on the tape. Both were on poles at the above mentioned intersection.
6. It seemed that the interference hacked up the upper part of the AM broadcast band, however, there seemed to be a high level of power line noise all over the city, (at least what I took to be power line noise) and this could have been what I was hearing.
There was one odd effect. Cape Girardeau has an AM station at 1550 kHz and in the test area, I was getting images of the station all they was from 1710 down #to 1600 kHz and again at 1520 kHz. Since I did not know where the station was located, I suspected that I was quite close to it and getting overload. However, when I left the test area, the images faded in about 1/2 mile.
7. I think I heard effects in the lower part of the FM broadcast band. #I was receiving audio from a TV channel 6 transmitter at the low end, and it definitely had some kind of interference on it that could also be heard to some extent on clear channels up the band. Again this could be regular power line noise.
8. It also seemed that the test area was extremely limited in scope being confined to the streets mentioned above as interference levels dropped on adjacent streets in the subdivision. However, I was using a Hustler, which is not the most efficient mobile antenna. I suspect that anyone using typical HF antennas at a fixed location anywhere in the subdivision would have a serious interference problem.
This was not a series of scientific measurements and no claim is being made for such. Rather it was just me, an average ham operator making a field trip to a test site wanting to hear for myself what BPL interference sounded like and if it is a bad as it is made out to be. In my opinion, it is every bit as bad and I can see where it has the potential to change ham radio as we know it and turn HF into a wasteland wherever it is deployed.
73
George
K3UD