How do I detect and measure RF/EM radiation?

[TedTheLed]

James, I didn't mean just cell phone towers, but, what IF cell phone towers made SOME people a little more nervous, a little more suspicious, angry,
paranoid, or depressed? Again I'm not talking tumors and death here, but subtle personality changes.. How would we possibly notice or discover this without a thorough campaign of questioning and examination of the people and the lives they live around the towers?
The only government I've heard of that actually asks it's subjects how they are feeling is the Tibetan, and they just want to know if you're happy.

There IS an experiment that has been done, with the subjects wearing helmet devices that generate very mild magnetic waves, that DID change their perception of truth and falsehoods. The waves affected what was called the "repudiation effect" of the brain, that is they eliminated it, so what a subject would normally say is false, they say is true under the waves affect -- I'll try to find it. Just saw it yesterday on TV..

 

[PhotonWrangler]

I know a guy who claims that he gets disoriented by strong magnetic fields.

This was somewhat "confirmed" when a co-worker who knew about his claim brought a large, powerful magnet within an inch of the back of the guy's head without his knowledge. He immediately became disoriended without knowing why.

You decide... :thinking:

 

[scott.cr]

I work for a company that manufactures high-power RF amplifiers. RF exposure is not a concern here, but RF burns are.

Medical MRIs use very high-intensity RF fields to induce proton spin. They do not consider this to be a hazard because it is non-ionizing ("radioactive") radiation.

However, that does not mean *I* trust "them" hahaha. While online Christmas shopping yesterday, I came across the Ramsey Tri-Field Meter kit. It's the lowest-cost tri-field meter I've seen @ $65.

 

[James S]

And if you do pick up the meter and find their output to be out of spec from what is allowed, you can call in the authorities and get them slapped with some not-insignificant penalties. So check up on them if you're interested, but dont be worried just because some RF is passing through you!

 

[hopkins]

Hi Lowbat
Recently noticed that when our neighbor turned on their laundry room fluorescent light AM radio reception was scrambled by loud 60hz buzzing.
I went over with a new ballast, explained to her the problem and got a free
drink after the repair.

Einstein said:
You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat

 

[BigusLightus]

LowBat,

The simple answer is to check the web and find the local Ham Radio Club. There will be some serious radio geeks there with serious equipment. They will be able to help you out and they will probably find it to be an exciting challenge.

James
KF4WXH

 

[LowBat]

Wow, I'm surprised this thread is still going. I no longer have a need for a detector as the place I was thinking of moving to (lots of antennas and electrical equipment) didn't happen. I do thank you all for your input.

 

[jrmcferren]

LowBat,

The simple answer is to check the web and find the local Ham Radio Club. There will be some serious radio geeks there with serious equipment. They will be able to help you out and they will probably find it to be an exciting challenge.

James
KF4WXH

Yes, what you are looking for is a field strength meter. Do not use an AM transistor radio for this purpose as it will be prone to front-end overload. Find out what is on this tower we may be able to help with that info.

 

[Joe_Beam]

While keeping the "inverse square law" in mind, there are antenna directional characteristics to consider. Most high power transmitters feed directional antennas. In these cases there may be less radio frequency emissions close to the bottom of the tower than there are when you move a slight distance away, at that point the inverse square law comes into effect. The frequency of the emissions determine the distance from the tower that you start to receive full power with respect to the type of antenna. If you are close to a tower, you can get the radiation info from the engineering department of the antenna owner. All commercial antennas are registered with the FCC and they also have this info.

PS: I know that the plural term for antenna is antennae (I'm just trying to keep it simple)

 

[Steve K]

Einstein said:
You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat

I forgot about that quote.. I may have to name my next cat "Ether".
(my current cat is named after Tesla)

Steve K.

 

[Steve K]

.... I can't help thinking that the immense magnetic fields present in everyday life both man made and cosmic have a profound affect on our brains..

but what if it was the magnetic fields that made you think that???

Generally speaking, I'm not aware of experiencing large magnetic fields in my daily life. The earth's magnetic field is probably the largest field I encounter on a regular basis. The next might be the little earbuds for my mp3 player/radio. I've had an MRI done on my brain too. I'm unaware of any mental/emotional/orientation effect of any of these.

As part of my job, I've spent a while working with rare earth magnets (500 gauss), use a gauss meter to measure fields, have built a helmholtz coil to generate modest uniform magnetic fields (50 gauss), and even made magnetic field measurements at a scrap iron handing plant (and measured the field at one of those giant electromagnets that they use to pick up the scrap iron!). I haven't noticed any effect as a result of being in proximity to magnets or magnetic fields.

I think there are risks to working around large electromagnetic fields. I've heard of stories of folks working with microwave communications amplifiers that put out enough power to make a bird go *pop* when it flew in front of the feedhorn antenna. The stories also say that if there was a RF leak in the room with the amplifier, they would feel sick. Obviously, these fields are hugely larger than anything most folks are exposed to. I don't know that I've ever heard any explanation of what the mechanism of the cause of such RF illness might be, and I've only heard this from a friend who heard it from someone else.

Since I do work with RF equipment as part of an EMC test lab, I'm careful about avoiding exposure when our amplifiers are running. The routine exposure to electromagnetic fields don't cause me any concern, though... (but I don't use a cell phone either. )

Steve K.

 

[Paladin]

I used to climb microwave towers. One project in a D.C. suburb met opposition from local residents concerned about the emi. The testing by a third party company found the levels to be minimal.

A far greater hazard is from dropped objects when maintenance is performed. Don't ask me how I know...

Paladin

 

[Paladin]

I used to climb microwave towers. One project in a D.C. suburb met opposition from local residents concerned about the emi. The testing by a third party company found the levels to be minimal.

A far greater hazard is from dropped objects when maintenance is performed. Don't ask me how I know...

Paladin

eta: double post from site issue!?

 

[PhotonWrangler]

I used to climb microwave towers. One project in a D.C. suburb met opposition from local residents concerned about the emi. The testing by a third party company found the levels to be minimal.
Paladin

I did an informal test at a microwave transmitter site once. There was a 10' Andrews parabolic with a +9dbm input from the transmitter, running around 13ghz. The primary lobe of the signal was quite tight, however it was still able to drive a radar detector absolutely nuts on the ground, about 75' from the tower. Even so I felt quite safe as this was still a very low level signal at ground level.

 

[BriteIdea]

This is the exact industry that I work in and I detect leaking RF coming from cable plants. Add to that I'm also a ham operator. The amount of RF that I detect is measure in micro-volts. We are also watched by the federal government guide lines and our idnexes are quite low.. Our measurements are in the VHF and UHF zone, while others can be in the 900MHz to GHz zones.

Please remember that any transmission site is strictly monitored by federal goverment and is why all these sites have to be licenced before they are approved.

The wost that anyone has to be concerned about is the typical cell phone that is commonly "glued" to a users ear. I don't know much about the details of cell phones so can't comment. The diffrence being is that it's the close proximity of cell phones to the human body.

As for any other RF "nearing" the human body you must also be aware of the inverse square law, which states that the RF power diminishes exponatially per distance away from the source.

If, for example you literally lived right under the tower and expose there for a long time, then you should, or could, have concerns. But if that same tower is across the road, that inverse square law takes over and the amount of power is insignificant.

I'm sure there are others that are better informed on the absolute details but my perspective is based on general theory and documentation.
Maybe it would be best to call your local FCC or Industry Canada Office and get the information straight from the horse's mouth.
Hope that helps