On 4/22/23 12:12 PM, GEO Badger via TowerTalk wrote:
Suggest you contact the company and ask them. They are not allowed to radiate
RF.
I'm sure they're allowed to radiate RF, just like any other electronic
device. The real question is "at what level can they radiate". They'd
be an unintended radiator - just like a motor controller, welding shop,
etc. Typically radiated emissions limits are imposed at the "box"
level, not at a system or "boundary of the property" level, and for
commercial equipment those limits are pretty liberal, and worse for this
they end at the terminals of the device. If you use a variable speed
motor drive (which uses PWM internally), and you hook up 1000 ft wires
to the motor, those wires make a fine and dandy antenna, as do the power
supply wires. You might look at CISPR11/55011 and IEC 61800-3.
The boxes would be Group 1 (basically anything other than an intentional
radiator) class A (not residential)
https://www.electronic.se/en/2019/06/01/emc-challenges-and-solar-panel-systems/
gives some field measurements of 50-60 dBuV/m in 1 kHz BW, at some
distance (probably 3 meters) in the HF band.
You'd need to convert that to "received signal power in a typical
antenna". Let's say 10 MHz, lambda = 30 meters, so effective aperture
of a dipole is 1.5 * lambda^2/(4 pi) so: about 110 square meters.
0 dBuV/m is 1 uV/meter so 60 dBuV/m is 1 mV/meter. Converting to power
density-> S = E^2/377 -> 1E-6/377 -> 2.65E-9 watts/square meter
* 110 is 0.29 microwatts = -35 dBm. which is pretty healthy.
But hopefully it falls off at 1/r^2 and it's not being radiated by a
power line. Get 300 m away and you'd be down to -75 dBm. that's around S9.
https://www.nrel.gov/docs/fy17osti/67440.pdf ; has some background info.
Things like Broadband over Power Line had specific radiated power limits
vs frequency, measured at a particular distance, etc.
Igancy NO9E sez:
I have a ham radio property in a rural area. Fairly quiet. My
neighbour informed me that a 1000 acre solar farm by Green Bolt is coming
within a quarter mile. I am contemplating another tower but I am not sure
now whether the site will still be ham friendly. Does anybody have any
experience regarding RFI from large solar farms?
---
Ciao baby, catch you on the flip side
73 de W3AB/GEOAFA9GB
WA2LSI, KE6RJW, W6B, W7B, AAR9AG
http://www.w3ab.org
Jazz is a pencil sharpener. Jazz is a frying pan… Jazz is a beautiful woman
whose older brother is a policeman
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|