2016-10-12, 13:23
Hi,
Thanks for the quick reply. I was interested to see if they should be the same gain or at least if most people have the same gain on each antenna, but as you say this isn't important, as long as it receives the signal from the lightning.
I have held a radio amateur license since 1980 and work in rf system design/production (although it is microwave now), so I am interested in the technical side.
To try to find out a little more, I moved my system blue from the attic to a summer house in the back garden. The gain for the two H field antennas stayed the same, but the gain for the E field antenna went up quite a bit, indicating that the E field noise is much lower in the back garden.
Although I am running much lower gain on my N/S ferrite rod, it still picks up lightning quite nicely from the south, so rather than the noise been more in this direction, I think it might be that my location has less attenuation N/S than E/W?
About 100m south of me there is a small electrical sub-station and then 400m south there are two sets of HV power lines, but with system blue in the back garden both of these will be below ground level as they are down in the valley. There is a TV and FM transmitter about 5km away, also to the south but I doubt it is that which is causing noise?
I did wonder if there are any good techniques to find noise? I had a look at some VLF active antennas, or perhaps make a receiver and feed it in to a sound input? Not sure if there is anything on the market?
I have one final question regarding ferrite rod antennas, I assume they are more directional than a loop? I also assume that shielding them makes them even more directional?
The reason for asking is that there was a fair bit of lightning to the south east of me a couple of days ago and I wasn't detected it as often as nearby stations which use loops. Yet when there is some due south, I was getting a lot of detections.
Thanks for the quick reply. I was interested to see if they should be the same gain or at least if most people have the same gain on each antenna, but as you say this isn't important, as long as it receives the signal from the lightning.
I have held a radio amateur license since 1980 and work in rf system design/production (although it is microwave now), so I am interested in the technical side.
To try to find out a little more, I moved my system blue from the attic to a summer house in the back garden. The gain for the two H field antennas stayed the same, but the gain for the E field antenna went up quite a bit, indicating that the E field noise is much lower in the back garden.
Although I am running much lower gain on my N/S ferrite rod, it still picks up lightning quite nicely from the south, so rather than the noise been more in this direction, I think it might be that my location has less attenuation N/S than E/W?
About 100m south of me there is a small electrical sub-station and then 400m south there are two sets of HV power lines, but with system blue in the back garden both of these will be below ground level as they are down in the valley. There is a TV and FM transmitter about 5km away, also to the south but I doubt it is that which is causing noise?
I did wonder if there are any good techniques to find noise? I had a look at some VLF active antennas, or perhaps make a receiver and feed it in to a sound input? Not sure if there is anything on the market?
I have one final question regarding ferrite rod antennas, I assume they are more directional than a loop? I also assume that shielding them makes them even more directional?
The reason for asking is that there was a fair bit of lightning to the south east of me a couple of days ago and I wasn't detected it as often as nearby stations which use loops. Yet when there is some due south, I was getting a lot of detections.