:smile:I must clarified once again. SAR rates is measure based on power density which is good predictor for twa exposure levels over 6 minutes. At this point there is not a form of measurement as I understand (e field, h field, power density etc) that will predict the total current induced on a...
Close proximity is a loose term which in this case any where that an induced current can occur since there is not enough science to set an standard for RF current induction besides AM broadcast as permitted by the FCC today could have a near field of up to 3km depending on the Antenna...
The near field radius for AM antennas is 3km and effective range is up to 20 miles. Here is a case from a reliable source: http://www.osha.gov/dts/hib/hib_data/hib19900905.html
However, and again not much as far as specifics goes. I would not disagree with most the statements (there should...
I am sorry you take this position about my responses because I wish I can contribute more specifics for you.
It is evident to me that you have not knowledge about radio frequency transmission, near, far field characteristics, much less to the question at hand "the phenomenon of re-radiation...
I was not clear about that. What I meant was that it only happens at certian set ups. for example if the hook is at ground level and the boom is at 60 degrees from the horizontal. However it does not happens when the boom is at 30 degrees and the hook is at ground level. I was trying to say that...
Generating antennas means just that (at the radio frequencies of course), however, the phenomenon is mostly attributed to AM frequencies. My motives are based on a general request. I will be doing a presentation about the case study. No much of specifics as that goes because it the nature of...
You are absolutely correct John. Correction: The crane is electrically (power source) grounded. This does not mean it is grounded for RF current because it has to deal with impedances (impedance matching). Most antennas are a little bit diferent than your normal electrical circuit (look into...
Presumably is because at those positions the crane creates a tune antenna (1/4, 1/2... wave). Reradiating the frequency (or frequencies), this could be a possible explanation why this occurs. I know this much in theory, however, I have never encountered the issue myself. I just gathering...
John Thank you for taking the time to reply. You can assume that the Tower crane (or it could be any mobile, gantry ect) is effectively grounded. The second assumption is that the crane is outside of the close proximity radius of the generating antenna. The phenomenon is usually associated with...
Can anyone explain why cranes in construction sometimes experience induced currents from antennas radiating from distances of up to several Kilometers.
I have looked into the phenomenon several times, and have not been able to find a study or baselines to follow. I have a basic understanding...
Can anyone explain why cranes in construction sometimes experience induced currents from antennas radiating from distances of up to several Kilometers.
I have looked into the phenomenon several times, and have not been able to find a study or baselines to follow. I have a basic understanding...