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BASE Technical

fuzrb14 Aug 31, 2009, 11:35 AM

AM question

To date everything I've read about AM towers leaves me with this profile of them:
- insulated legs
- no "extras" on the tower

.. but just recently I found a tower that is not only insulated, but also has a stinger on the top and various satellite dishes. Not to mention the stations building has been abandoned. Does anyone know of a way to check and see if it is an anomaly of the AM tower world or one that has simply been converted to FM.

And "no" I have no desire to simply touch it and see if i get grounded Crazy

Crazy

Thanks in advance

vid666 Aug 31, 2009, 11:40 AM

Re: [fuzrb14] AM question

There are such things as hybrid towers - where it's an AM tower that has other non-AM equipment on it. The tower itself is still a transmitter.

that's all I can offer. Obviously, if in doubt - let the new guy go first...

baseknut Aug 31, 2009, 1:48 PM

Re: [fuzrb14] AM question

if the com building is abandoned its likely that the tower is rather old. research it on asr.

that being said, it is possible that when it was an active AM tower it was de-commissioned and the owner of the structure now rents space to other transmission and broadcast companies.

~Jake

fuzrb14 Aug 31, 2009, 2:05 PM

Re: [baseknut] AM question

Well I really hope that it's been converted, but I'm primarily interested in a way to personally check and see whether or not it's transmitting in AM. i.e. using a volt meter <- probably a dumb idea but something along those lines?

TomAiello Aug 31, 2009, 3:44 PM

Re: [fuzrb14] AM question

Get the tower number off the gate (by law, it has to be posted there) and put it into the FCC database. That'll tell you what, if anything, it's transmitting.

runnit Aug 31, 2009, 3:59 PM

Re: [fuzrb14] AM question

If you can identify the station, just come up with a story about being an amateur radio enthusiast or something equally innocent and nerdy sounding and give the station engineer a yell. That's what I did for some towers near me that I was unsure about and he was pretty happy to go into all sorts of technical specs.

The bloke who runs this website is also more than happy to talk your ear off about antennas and can help identifying any weird features to do with the tower http://www.waniewski.de/id208.htm

stitch Aug 31, 2009, 6:18 PM

Re: [fuzrb14] AM question

Pay a homeless person 5 bucks to piss on it. If he/she flies backwards through the air for 100 yards then it is hot.

gromet Aug 31, 2009, 9:55 PM

Re: [fuzrb14] AM question

Okay, so I have a bit of a problem with this AM antenna paranoia. There are two main things that make me think it's all exactly that, paranoia.

First, has anyone ever seen a fence higher then waist high around one of these things? I doubt it. I have a hard time believing that in this sue happy country that an antenna owner would risk the possibility that some homeless guy was paid $5 dollars to piss on it.

Second, this is from a friend of mine that is very knowledgeable when it comes to electronics and the like. He has told me that in the case of an AM antenna the reason they are designed with the insulator leg the way it is is so that they can complete a loop or circuit. From basic electronics we know that a current will always take the easiest path which is fortunately not going to be through our relatively un-conductive bodies.

Lastly of course I have to add this one little caveat. I personally know f#@k all about electronics or antenna, but I will say this. I've climbed them and had no problems. It's your call, have fun, be safe.

hookitt Aug 31, 2009, 10:25 PM

Re: [gromet] AM question

Did you just grab the ladder and climb it?

Kiki32 Sep 1, 2009, 12:19 AM

Re: [hookitt] AM question

First time I climbed an AM I did just that and got a nice shock.

blitzkrieg Sep 1, 2009, 12:21 AM

Re: [gromet] AM question

awesome post.
correct me if my summary is wrong:

your theory is paranoia.

you know nothing about antennas.

your best information is from a friend.

you think the human body is a poor conductor.

you've climbed "them" and had no problems.

oh, don't forget the "be safe" caveat!

gromet Sep 1, 2009, 9:21 AM

Re: [blitzkrieg] AM question

Do you have anything to say? I'm putting out my opinion and experience. What are you offering?

GreenMachine Sep 1, 2009, 9:40 AM

Re: [gromet] AM question

Do you have anything to say?

Sure Smile

Smile

Gromet, have you jumped an AM tower?

None of us know your friend, hence
we are not likely to trust his input.

I have met & jumped with Blitzkrieg
hence I trust his input on the subject.

The guy who taught my BASE course
has over a 1,000 jumps and told me
about the time he landed from an AM
jump and puked for over 20 minutes.

I personally am getting by sticking to
TV, FM, Cell, and of course my favorite
those red freestanding dead towers Wink

Wink

blitzkrieg Sep 1, 2009, 10:06 AM

Re: [gromet] AM question

In reply to:

What are you offering?

advice based on professional experience.

http://www.basejumper.com/...=am%20tower;#2902224

but, this is the internet, so i suppose anyone is free to give advice based on hearsay.

AM radiation is bad for you whether you're paranoid about it or not. can you jump them? sure. will they shock you? maybe. will it conduct and transmit through you? definitely.

as you say, it's your call. personally, based on things i actually know and have learned working on them, do not meddle with them unnecessarily. there are just way too many other towers out there with less risk and exposure.

the only reason i even give a shit, is because again, i actually know the OP and would prefer he not be advised to do things that will harm his health.

furthermore, towers are boring unless they are terminal tall, or dirty dirty low.

gromet Sep 1, 2009, 10:08 AM

Re: [GreenMachine] AM question

I have jumped them. I know you don't know me and I don't expect you all to "believe" me. I don't claim to be an expert. I'm only trying to look at this subject logically and perhaps reassess the data we have available to us.

I've heard of people puking, fillings getting rattled, etc. It all sounds bad, but I'm wondering if perhaps this is due to other reasons not related to the AM signal for the reasons I mentioned above.

Perhaps there is a bad insulator, perhaps the antenna are identified incorrectly, maybe there are other array on the antenna.

Bottom line is I think there may be other factors at play here that if researched a bit more, could potentially open up a couple of easily accessible objects. I am looking into the AMs around my area and will keep you all posted. Here's hoping for no pukey.

vid666 Sep 1, 2009, 10:18 AM

Re: [gromet] AM question

Dude. Depending on the transmitting power, AM will heat/boil things. It's a fact that nobody here (except for you) is questioning.

A bad insulator will ground the tower, and will send warning alarms for techs to shutdown/fix ASAP.
To reiterate on your "logic" - AM tower is a transmitter in itself, thus you are getting the most exposure by being ON It. A bad insulator will reduce/eliminate the power as it will be fully or partially grounded. How the fuck is that supposed to make you puke more, if you have a lesser exposure ?

Just like blitzkrieg I stay away from them, as do many others.

lowcountryBase Sep 1, 2009, 10:30 AM

Re: [fuzrb14] AM question

my best advice is to just wait; because 12 hours later it will turn from AM to PM and then you have nothing to worry about....right?

gromet Sep 1, 2009, 10:40 AM

Re: [vid666] AM question

Okay. I know most of us stay away from them, but I'm wondering if perhaps we're staying away from them for the wrong reasons. Which could also mean that we are staying away from the wrong ones when we could be jumping some of them.

And yes people are questioning whether or not AM antenna's will boil you that's why this thread is here. What I'm trying to figure out is why we think they will boil us and since we know that they get climbed sometimes without consequence and sometimes with, what differentiates the two scenarios.

I for one would like to find an explanation for this. Perhaps some of us are just harder then all you soft-- oops gotta watch out for the moderator ;) Or perhaps there is a reason sometimes people get juiced and sometimes they don't.

Wouldn't you like to know?

vid666 Sep 1, 2009, 10:48 AM

Re: [gromet] AM question

a person who has done any research knows that the radio stations use different power. It thus logically flows that the more power - the faster and the more pronounced effect the signal will have on your body. what I am saying is that spending 10mins on a 500w tower will probably feel a lot better than 10 mins on a 10Kw tower

also, AM tower transmit lower power at night than during the day, and some station go off-air at night.

what the fuck is a "wrong AM tower" as per your post ???

gromet Sep 1, 2009, 11:01 AM

Re: [vid666] AM question

That's a good point vid. The AM antenna I've jumped have been at night. Very possible that they were not transmitting or had turned it down. Looking into broadcast schedules might help determine good times to jump certain antenna.

As far as "wrong AM tower" I merely mean stay away from ones that tickle and jump the ones that won't.

wwarped Sep 1, 2009, 11:13 AM

Re: [gromet] AM question

gromet wrote:

I for one would like to find an explanation for this. Perhaps some of us are just harder then all you soft-- oops gotta watch out for the moderator ;) Or perhaps there is a reason sometimes people get juiced and sometimes they don't.

Wouldn't you like to know?

blitzkrieg provided a link to another thread.
this has been discussed many times. I believe antenna workers have chimed in, possibly electrical engineers, as well as people who have jumped them.

over time, the consensus became - stay away.

if you have a burning desire to know more, feel free to do some research and see what has been said in the past. call up people. talk to the guys who maintain the tower. investigate. go for it.

educate yourself!
put your enthusiasm to work.
it's a beautiful thing.

gromet Sep 1, 2009, 11:54 AM

Re: [blitzkrieg] AM question

When you worked on these guys did they shut them down? Turn down the broadcast power? Anything along those lines? What were the general safety precautions when working on them, that sort of thing.

Also, what do you think the difference is between grounding techniques between single foot guyed and multi-foot non-guyed? Would this make a difference?

It seems to me that the main issue we are dealing with is the same as micro-wave machines and water molecules, but on a larger scale. Since AM transmission waves are so much longer then us we are only exposed to the background noise which depending on broadcast strength could be significant or not. Obviously not a real reassuring argument Tongue

Tongue

but still a valid one.

Some AM antenna, sometimes, but apart from a bit of vomiting and a leg or two too many on your offspring, they might not be too bad.

Kiki32 Sep 1, 2009, 1:53 PM

Re: [GreenMachine] AM question

GreenMachine wrote:

The guy who taught my BASE course
has over a 1,000 jumps and told me
about the time he landed from an AM
jump and puked for over 20 minutes.

I used to get very nauseous my first few times jumping AM. Doesn't really happen anymore though.

Redline165 Sep 1, 2009, 2:44 PM

Re: [Kiki32] AM question

Let me Rephrase the original question, The site is set up strange. ASC is vague on the details, as was the man on the other side of the telephone when someone called acting as a concerned potential home buyer in a neighborhood near by. This is not the only tower near by and details on wiki and ASC and the person on the phone are sketchy.

From the looks of the tower it is perfectly jumpable but before we go and "just do it" we would like a way to know if it is hot or not. If its active, we will simply stay off. That being said any electrical gurus know of a way to simply walk up to the tower with a volt/amp meter and simply test for current?

hikeat Sep 1, 2009, 3:03 PM

Re: [Redline165] AM question

When I worked for a sign company, we used testers that looked like a pen and would beep when you get it near a live wire. you can get one for $15 at Home Depot.

http://www.homedepot.com/...&catalogId=10053

GreenMachine Sep 1, 2009, 3:08 PM

Re: [Kiki32] AM question

Kiki32 wrote:

I used to get very nauseous my first few times jumping AM.
Doesn't really happen anymore though.

Awww shit, one of the hottest chicks in BASE
has finally fried herself, shit, shit, oh shit.

Have you ever seen the movie "The Fly"?

Well at least I never have to waste a pack job by
offering you my 2nd rig, which is in production Tongue

Tongue

edit to correct spelling

GreenMachine Sep 1, 2009, 3:17 PM

BEST REPLY YET!!!

hikeat wrote:

When I worked for a sign company, we used testers that
looked like a pen and would beep when you get it near a
live wire. you can get one for $15 at Home Depot.

Nothing like a $15 solution to put an end
to hours and hours of internet bullshit. Laugh

Laugh

Hey Zach, wanna jump soon bro?
I got laid off and have free time Wink

Wink

gromet Sep 1, 2009, 3:38 PM

Re: [hikeat] AM question

That thing looks awesome, but we know that AM antenna's have current. The question is is it harmful and if so how harmful. Nausea harmful or blow my shoes off harmful? Also is it lasting?

I got no problem putting a 9V battery on my tain- I mean tongue, but wouldn't do the same with the distributor wire from a car.

Do you know if they make those no-contact meters that give out a numerical display as opposed to just a beep or light?

hikeat Sep 1, 2009, 4:07 PM

Re: [gromet] AM question

In reply to:

That thing looks awesome, but we know that AM antenna's have current.

No shit, my post was in reponse to Redline165.

In reply to:

we would like a way to know if it is hot or not....a way to simply walk up to the tower with a volt/amp meter and simply test for current?

I have never seen a no-contact meter that gives a numerical display. However, at your local hardware or electrical supply store you can get voltage meters that have insulated handles and will display voltage, ohms, and maybey a couple other things. I have no idea how that would convert to amount of radiation exposure.

gromet Sep 1, 2009, 4:16 PM

Re: [hikeat] AM question

If we're still talking about AM antenna then I don't think we need to worry about "radiation". So you can probably leave the geiger counter at home.

runnit Sep 1, 2009, 4:18 PM

Re: [gromet] AM question

Another way to see if a tower is transmitting is to approach it with a compass. If it's transmitting, as you walk toward the tower the needle will spaz out (especially with the field around a live AM tower) . I've done this near a 5000 W tower and it was really obvious even from about 200 m away. The needle swung every few paces.

WRT to the discussion about health effects and stuff, I've found a little bit of info on the net.

The general consensus seems to be that the long term health issues are inconclusive, but absorbing RF radiation (MF through to microwave) will cause water in your tissue to heat up (think fragile tissue like your brain, eyes and inner ear). Also consider that your average house hold microwave works between 700 - 900 W and this is close to the bottom end for most radio tower specs that I've seen (apart from maybe some poxy little local stations).

(Disclaimer - I'm a civil engineer, not electrical, so I'm not 100% about stuff that I can't actually see or push)

Here's a couple good links...

http://home.comcast.net/...in1/RFSafetyHam.html - simple, claerly written, but not many references
http://www.mapcruzin.com/...uency/henry_lai2.htm - a lot more technical if you want to go into depth

fuzrb14 Sep 1, 2009, 4:23 PM

Re: [gromet] AM question

now that you mention it I actually do have access to a geiger counter...... might be worth a shot Tongue

Tongue

Ghetto Sep 1, 2009, 4:39 PM

Re: [gromet] AM question

gromet wrote:

If we're still talking about AM antenna then I don't think we need to worry about "radiation". So you can probably leave the geiger counter at home.

That's good.. because a geiger counter, which detects radiation in the form of subatomic particles being ejected from the nucleus of an atom, wouldn't really do a very good job of detecting electromagnetic radiation, which is what towers transmit. Wink

Wink

gromet Sep 1, 2009, 5:04 PM

Re: [fuzrb14] AM question

Ooh, ooh, just found this.

http://www.rwonline.com/article/9210

Gotta love the title. Turns out you just need to ask the right questions Laugh

Laugh

Redline165 Sep 1, 2009, 9:09 PM

Re: [runnit] AM question

runnit wrote:

Another way to see if a tower is transmitting is to approach it with a compass. If it's transmitting, as you walk toward the tower the needle will spaz out (especially with the field around a live AM tower) . I've done this near a 5000 W tower and it was really obvious even from about 200 m away. The needle swung every few paces.

WRT to the discussion about health effects and stuff, I've found a little bit of info on the net.

The general consensus seems to be that the long term health issues are inconclusive, but absorbing RF radiation (MF through to microwave) will cause water in your tissue to heat up (think fragile tissue like your brain, eyes and inner ear). Also consider that your average house hold microwave works between 700 - 900 W and this is close to the bottom end for most radio tower specs that I've seen (apart from maybe some poxy little local stations).

(Disclaimer - I'm a civil engineer, not electrical, so I'm not 100% about stuff that I can't actually see or push)

Here's a couple good links...

http://home.comcast.net/...in1/RFSafetyHam.html - simple, claerly written, but not many references
http://www.mapcruzin.com/...uency/henry_lai2.htm - a lot more technical if you want to go into depth

Thanks man! Great idea, never thought of using a compass. Ive got an amp meter, and a volt meter, and pretty much every other type of meter. I think out happy number for everything here is "0". im just going to fill a back pack with every electrical tool ive got and see which one lights up!

thanks to the people with useful posts.

blitzkrieg Sep 2, 2009, 12:45 AM

Re: [gromet] AM question

gromet wrote:

http://www.rwonline.com/article/9210

see, there you go! that is pretty much spot on.

when i worked on them, they had to be shut off or turned down very low. i prefer off, especially if it will be a while.

Ronald Sep 2, 2009, 4:59 AM

Re: [blitzkrieg] AM question

No experience in jumping any AM tower, Blush

Blush

but we have this tower not far from my place. Is sure looks like AM, it has isolator on the cables, but no isolator on the bottom of the A. So, would this be an AM one? Height is 300 ft.

Ronald

blitzkrieg Sep 2, 2009, 7:26 AM

Re: [Ronald] AM question

it fits the bill. they are not always insulated from the ground, although it's hard to tell whether it is or not from the picture. but judging on the pictures of the tower alone, i would say that yes, it is an AM tower.

leroydb Sep 2, 2009, 10:08 AM

Re: [wwarped] AM question

I like the enthusiasm, but hell he wants to "argue" or "discuss" whatever you wish to call it. Contrary to his thought processes, he dosen't seem open to what we are saying.....

I think , he wants us to say, " hey we've been wrong all these years about AM towers, fuck lets start jumping them...."

then again I could be wrong Crazy

Crazy

Kiki32 Sep 2, 2009, 10:31 AM

Re: [runnit] AM question

runnit wrote:

Another way to see if a tower is transmitting is t
The general consensus seems to be that the long term health issues are inconclusive, but absorbing RF radiation (MF through to microwave) will cause water in your tissue to heat up (think fragile tissue like your brain, eyes and inner ear). Also consider that your average house hold microwave works between 700 - 900 W and this is close to the bottom end for most radio tower specs that I've seen (apart from maybe some poxy little local stations).

For what its worth (and I know it sounds preposterous), those first couple times I climbed AM and got sick, I had this smell in my nose of a metallic burning of sorts. And i know it wasn't just the antenna because I smelled it even on the way home. Thought it was kinda creepy.

gromet Sep 2, 2009, 10:33 AM

Re: [leroydb] AM question

Yes that is what I want you to say. I am however aware of the very distinct possibility that AM towers are just not very jumpable, but I figure it's a worthy "discussion" for multiple reasons.

First, I and almost everyone else on this forum or at least a friend of theirs has jumped an AM at least once and lived to tell about it. Some for better or worse.

Second, why not figure out a distinct reason or explanation for why the experiences range from didn't feel anything to vomited for 20 minutes. Which I might add the article I posted seems to explain. Different power outputs can increase or decrease the amount of RF radiation we are exposed to on any given climb.

Lastly I don't think that questioning long standing conventional wisdom is bad thing if it is done in a deliberate and purposeful manner. Unless you would like to argue that the world is still flat and only 5000 years old, in which case stop trying to question what we already know.

Here's to rockin the boat.

gromet Sep 2, 2009, 10:36 AM

Re: [Kiki32] AM question

hahaha, that sounds way creepy. Maybe that's the same smell in my room after a hard weekend of substance abuse. Soft tissues slowly getting eatin away.

GooManChew Sep 2, 2009, 11:24 AM

Re: [gromet] AM question

gromet wrote:

Unless you would like to argue that the world is still flat and only 5000 years old, in which case stop trying to question what we already know..

these guys will . . .

runnit Sep 2, 2009, 3:17 PM

Re: [Ronald] AM question

Is that grey thing at the bottom of the tower in the 3rd photo an insulator or aren't the feet of the tower in contact? It's hard to tell from the photo.

I've sent the photos to an operator mate of mine to see what he reckons, but I think that the dipole at top of the tower (the wires strung horizontally like a hammock) is the actual transmitting element and the towers would just be a support structure. That doesn't explain the insulated guys, but having 2 different transmitters so close to each other and in different polarisations seems a bit weird... (civ eng disclaimer again! Tongue

Tongue

)

runnit Sep 2, 2009, 5:19 PM

Re: [runnit] AM question

Ok, my mate just got back to me and that is a HF antenna (slightly higher freq than AM which is MF, FM is around the VHF band), so it's probably used for 2 way comms, not continuous broadcast

The tower is just a support structure, but it is also used as an earthing braid. The antenna is insulated from the tower, but as it transmits it builds up a static charge which eventually jumps the gap and discharges down the tower.

Being HF, you might be able to assume that it's only live when someone actaully transmits. If you can find out what it's used for, you might be able to have a better guess about when there will be the least traffic on that particular net. You wouldn't want to be earthed at the wrong moment though.

blitzkrieg Sep 2, 2009, 10:16 PM

Re: [runnit] AM question

Yeah, i didn't notice the dipole in the picture. HF makes sense. and that if it's transmitting, is probably even worse for you. Tongue

Tongue

definitely don't touch that!

Kiki32 Sep 3, 2009, 10:15 AM

Re: [runnit] AM question

runnit wrote:

You wouldn't want to be earthed at the wrong moment though.

3....2....BZZZZTTTT Crazy

Crazy

Crazy

Crazy

Crazy

Pirate