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Hi Humans,

I have been looking for information on which fm towers are really stupid to run and which are just stupid and acceptable.

Currently looking at climbing a 500ft free standing with an omni-directional 50kw Digital TV and Directional 59kw FM Radio transmitter...

Would this be considered a little too powerful to be around?

Thanks in advance,

Fellow Human.

I'm ok with being on top of a 2000' TV tower for the brief time it takes to jump. Look into the OSHA guidelines for tower workers regarding nonionizing radiation. From everything I've read, it's ok. Especially considering the brevity of exposure and the much lower radiation while below the emitters

Thanks for your reply dude.

Yeah from what I have read - it should be fine for a short amount of time (as long as I stay away from those directional drums).

Thought i'd see what others have to say.

Awaiting any other responses.

Thanks.

I've done as much research as I can and from what I understand the AM radiation is non ionizing, doesn't give cancer and heats up your body if you remain on them for too long. The radiation from the directional transmitters is much stronger and concentrated and you do want to avoid them. Another thing about the AM, you need to find out the output. There is one near us here and it has a very high output, transmitting across the country. If you attempt that one nausea and headaches are a guarantee so it's off limits. I'll try and get some info to illustrate.

Did you mean FM?

Hey bro,

Thanks for the response and info - handy, for sure!

However, I am asking about TV and FM Transmission (not sure if they're the same).

Sorry, i was referring to AM omni directional masts. Any FM I stay well away from.

What is the reason you stay away from FM? (This is what I am trying to figure out :P, bahah)

If you're a BASE jumper, you're much more likely to die making a really stupid rigging error or trying to fly a wingsuit through a whales blow hole or some equally stupid shit. The antenna radiation you speak of ain't gonna hurt you enough for you to ever notice it in your short life.

FM waves contain much more energy. hence why you don't wanna be near it for long. We jump a mast with a big FM TV array at the top, and we stay there for as short a time as possible. Xrays and gamma rays will shoot through you and give you cancer. High frequency radio waves will not.

Found this also:
Biological effects that result from heating of tissue by RF energy are often referred to as "thermal" effects. It has been known for many years that exposure to very high levels of RF radiation can be harmful due to the ability of RF energy to rapidly heat biological tissue. This is the principle by which microwave ovens cook food. Tissue damage in humans could occur during exposure to high RF levels because of the body's inability to cope with or dissipate the excessive heat that could be generated. Two areas of the body, the eyes and the testes, are particularly vulnerable to RF heating because of the relative lack of available blood flow to dissipate the excessive heat load. At relatively low levels of exposure to RF radiation, that is, levels lower than those that would produce significant heating, the evidence for harmful biological effects is ambiguous and unproven. Such effects have sometimes been referred to as "nonthermal" effects. It is generally agreed that further research is needed to determine the effects and their possible relevance, if any, to human health.

Some studies have also examined the possibility of a link between RF and microwave exposure and cancer. Results to date have been inconclusive. While some experimental data have suggested a possible link between exposure and tumor formation in animals exposed under certain specific conditions, the results have not been independently replicated. In fact, other studies have failed to find evidence for a causal link to cancer or any related condition. Further research is underway in several laboratories to help resolve this question

Thank you for your informative response bro.

From what I have got out of the research i've done so far. I believe what matters is the Frequency and not the power...

For example: a omni-directional transmitter, Freq:200mhz @ Power:50kw

It's only the 200mhz frequency that is dangerous... Correct me if I'm wrong please?

I also found this little chart on the net, check it out... Let me know your thoughts.

Thanks humans.

In my experience the power is a major factor. There is a 5kv antenna we hit which is fine and a 50kv long range AM mast that you would stand near let alone climb. This is AM mind you.

Regarding FM vs. other kinds of modulation (i.e. AM)

FM not the issue-- it's a combination of band/frequency, signal power, proximity, and length of time. It may so happen, that the highest-risk transmitters coincidentally modulate the signal by FM, because of how governments divide up the spectrum for different kinds of usage. Your body does not care if it is AM or FM, per se.

The 30-300 mHz band (1-10 meters) is considered the highest risk according the U.S. occupational health standards. Note that public FM radio stations fall in this range, but AM radio stations do not. AM transmitters can have more power*, but your body is not as efficient at absorbing it. Don't base your actions just on that though.

In addition to directly heating your body, a transmitting antenna could also heat metal and then you get a thermal burn from touching the metal. Examples could be a piece of the antenna that you grabbed, or it could be a metal wristwatch band, for instance. The frequency that heats up the metal thing, might be a very different frequency than what would heat your body up.

And you could always get electrocuted by touching the wrong thing, regardless of the frequency.

TL;DR- Go with a mentor, don't linger near a transmitting mast, and don't touch anything that doesn't look like a ladder or a railing.

Other sources:
https://www.fcc.gov/...safety/faq/rf-safety
http://www.who.int/...ions/facts/fs226/en/

edited for clarifications/spelling

*yes, photon for photon, higher frequency is higher energy (E=hf) but that's not the relevant part

What we did in the old days was a 3-ring kiss. If the little ring burns your lip, better jump very soon! ;-)
Take care,
space

Thank you very much for the info!

BAHAHAHAHAH this is legendary. I will use this technique - seems to make the most sense to my very small brain.

I've actually seen the rings heat up enough to start damaging (by melting) the riser webbing.

I flew through your moms blow hole

you just got lucky...

Gross. can you relate more about the circumstances, or the power & band of the antenna?

If any one wants to hear in interesting story about this just ask Jester, last time I was in Twin he was telling the story of how on a BASE jump on a fairly tall tower, still using sky gear, his 3 ring melted through one of his risers and on opening he was only connected by one riser. I believe he cutaway and opened a round reserve is how the story goes.

And people that do wingsuit Base think they are so hardcore

I was waiting for his story to be mentioned! It's a good one!

The only thing that will hurt you quickly is close proximity to a leaking wave guide. Do some googling and be sure to be able to identify them, assume all are leaking, and just avoid coming within 10 feet of them if possible. They'll hit you with enough juice to blind you within 2 minutes exposure, where even high-emitter dose is generally ok for under 6 minutes.

??? That doesn't make any sense to me...how could you get way more powerful radiation? What do you mean by leaky wave guide? Do you have any links for "leaky wave guides" as it relates to any sort of emitter that may be found on an antenna?

Check out the link below (particularly page 20 for wave guide info but whole thing is a good read for dudes who like to hang out on antennas). I don't know enough about the science to say exactly what is the waveguide threat mechanism. The takeaway for meat huckers is that RF energy on its way from the amplifier in the antenna bunker to the emitter on the antenna is extremely concentrated in the waveguide, and leaks there are the most serious short-term-exposure threat. Broadcast antennas of any kind emit waves of radiation in the RF frequency spectrum that is non-ionizing. So like your microwave it will make the electrons in your atoms and molecules dance and warm up, causing thermal damage if the exposure is strong enough for long enough. Contrast this with higher-frequency nuclear radiation, which is so strong it strips the electrons from your atoms and molecules regardless of time of exposure, immediately causing permanent damage. The relevant inquiry for jumpers is how long you expose yourself to the RF frequency, and generally unless you're shitting yourself for 20 minutes right next to the emitter while you talk yourself into sending, you'll be fine. Most emitters are ok to stand next to for six-ish minutes while you nut up and gear check. Beyond that you may have mild heat-related exposure symptoms. Next to a wave guide that isn't working correctly, you may experience heat damage in as little as two minutes. Just move fast, stay away from wave guides, and have a good jump.

http://www.sbe.org/sections/documents/RFSafetyTrainingHandout.pdf

Jester had a riser release allegedly due to the small ring burning through the retaining loop on the riser back in the late `80s.
Take care and kiss your gear (and the sky) often.
space