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Hi,
I have just received my system blue and going to make E field and H field antennas. I have a couple of questions:
What is the minimum height for the E field antenna?
If I mount the system blue in my shed then I doubt I can get the E field antenna above 5m.
If I put the E field antenna in my house the E field antenna will have to go on my wind speed/direction mast, the wx station transmitter is located about 4m below, will this be okay as the speed/direction is just low frequency switch contacts?
The H field antenna is going to be two ferrite rod antennas, these will probably be in the loft. I assume that these are both mounted horizontally, one facing east-west and the other north-south?
If I put my system blue in a remote location and use a wifi router what is the minimum recommended distance from system blue to wifi?
Sorry for the stupid basic questions but I would like to get it installed in the best place first time.
Thanks
Robin
Posts: 1,220
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Joined: 2012-07-01
There is no lower limit for the height of the E-field antenna - If the antenna stood far out on a grassy field, it might be a few cm above grass height.
If it is to be able to "see" far omnidirectionelt, it should be just above the highest point (ideally)
At the top of a mast is very fine, but it may also be a piece down the mast - If metal mast, do a space of 10-15 cm from antenna to mast.
Do not compare the E-field antenna with a radio/television antenna, which can only see just over the horizon. E-field signals are more tolerent.
An electronic weather station sends pulses and not only DC signals. Although these are at a low frequency, the switches can generate interfering signals.
You can create a temporary setup where the antenna comes near the anemometer and wind direction indicator to check it out, before you set it up permanently.
Ferrite antennas in a horizontal cross on the ceiling is really good as long as they are kept as far away from electrical installations (preferably more than two meters)
It need not be NS / EW but it is practical to do so.
Distance between WiFi units depends on the situation - you can not not say anything specific about that.
It is not difficult to test, because BLUE just need 5 volts to operate, so it is easy to move around during the test.
/Richo
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I can mount two ferrite antenna and an E-field antenna in TV antenna pole?
if you are a good location?
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Yes, it's a good position
/Richo
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Thanks Richo.
It is better to put in different places (distant) antennas in ferrire and E-field antenna?
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They can be in the same box if you like
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Does the E-field antenna need to be a certain height above a metal roof?
Will the ferrite antenna be attenuated if placed in the loft which has a metal roof?
Thanks
Ian
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E-Field need to be outside - works if it's just over the roof. BUT it must be free from mains and other disturbances.
H-Field is pure magnetic, and since it's hard to screen magnetic fields, it works under a metal roof.
I would give ferrite antennas at least 10 cm from metal and loops at least 50cm
Metal roof should not be connected electrically to pre-amps, but may be grounded
/Richo
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2017-11-04, 07:39
(This post was last modified: 2017-11-04, 07:42 by RichoAnd.)
doubble post :-(
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Thanks Richo for this excellent information ... I operate an amateur radio station at home operating mainly on the 2M band @ 145.175Mhz with 40W - do you think this will cause an issue? I plan to place the e & h antenna as far as possible from the 2m antenna.
I also have solar panels with micro-inverters that communicate over the internal electrical wiring - have you heard of issues caused by power line communications?
My System Blue was posted the other day so I'm getting myself organised in advance.
Regards
Ian
Posts: 177
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Joined: 2013-12-14
(2017-11-04, 08:26)vk2him Wrote: Thanks Richo for this excellent information ... I operate an amateur radio station at home operating mainly on the 2M band @ 145.175Mhz with 40W - do you think this will cause an issue? I plan to place the e & h antenna as far as possible from the 2m antenna.
I also have solar panels with micro-inverters that communicate over the internal electrical wiring - have you heard of issues caused by power line communications?
My System Blue was posted the other day so I'm getting myself organised in advance.
Regards
Ian
Ian, I used to use Ethernet over power adapters before I had a Blitzortung station, they caused huge amounts of RF noise across a wide spectrum and one of the first things I did was to give them away to someone who lived a good distance from me, I wouldn’t touch them again, I think a lot of radio amateurs have similar views on them.
I have also read of noise problems with solar inverters but don’t have any myself so cannot comment further.
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