Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: 100,000 volts and my antennas  (Read 3146 times)
KC2VOB
Member

Posts: 49




Ignore
« on: February 05, 2012, 04:53:15 PM »

I’m buying a piece of land for home where I’ll have a 150’ tower for my antennas. But there are power lines that carry 100K volts about 200’ above the ground, about 500’ away from the sight that I want to buy for home. Do you think that will be a safe set up? How far should antennas be from these power lines to avoid interference and any possible danger?
Logged
K6UJ
Member

Posts: 311




Ignore
« Reply #1 on: February 05, 2012, 07:09:46 PM »

Tune your car radio on AM and select a freq between stations and I'll bet you get power line noise radiated from the lines.  Thats too close for comfort in my opinion,  Even with out any arcing insulators, etc you are risking radiation on the ham bands from this close of a distance.  If you have a mobile HF radio, even better, put it on 80 meter AM and see what happens. 

Bob
K6UJ
Logged
AJ3O
Member

Posts: 124




Ignore
« Reply #2 on: February 05, 2012, 09:08:56 PM »

There should be no danger if your numbers are even close.

But as for the interference, well, you will just have to go with the last suggestion nd see how bad it is. There are plenty of power lines close to many Hams but that does not stop them from operating.
Logged
K0ZN
Member

Posts: 1548




Ignore
« Reply #3 on: February 05, 2012, 09:11:14 PM »

Hi.

From a true "danger" standpoint, you are totally safe.  500 feet is a "long way away".

From an RF noise possibility, you are in a pretty high risk situation....not guaranteed, though.
There are a pretty fair number of big high lines that are amazingly quiet, even at HF......and they can be really bad. The worst part is, the situation, what
ever it is, quiet or noisy is not stable over the long run. It can change. I have a major line cross country line that is about a half mile from me. It is not a problem
at all, but I have had all kinds of problems with the 7200 V local line and especially with an area feeder that is something like 22 KV; it is nasty, in terms of noise.

Bottomline:  Generally, the farther you are from any larger line the better off you are.  Personally, being serious about my radio hobby, I would not buy
                 a house or property that had a high line that close.  .....just my two cents.

73,  K0ZN
Logged
K9KJM
Member

Posts: 2415




Ignore
« Reply #4 on: February 05, 2012, 09:21:17 PM »

I agree.    From a safety standpoint, 500 feet away is plenty far enough.

The suggestion to drive around near the lines while listening to an AM broadcast band radio is good, So would listening on some other frequencies if you have any type of portable or mobil radios.....

Around here, The power companies take very good care of the high voltage transmission lines
ATC (American Transmission Company)  It is the local distribution lines at 9600 volts that sometimes get neglected and make noise.

I am very lucky that the local distribution utility here takes interference very seriously, And maintains a good clean electric plant.   Just a few miles away in a smaller city it looks like the utility there uses the throw away insulators from here!  Driving around that city with an AM broadcast radio gets you nothing but buzz!

http://atcllc.com/
Logged
W8JI
Member

Posts: 9296


WWW

Ignore
« Reply #5 on: February 07, 2012, 05:45:39 AM »

The problems with listening to the power lines on the AM BCB is:

1.) Because a line is quiet or noisy at one time, does not mean the line will remain that way even minutes later, let alone days or years later. If it does act up, and someday it probably will, it is much more difficult to get a HV line repaired.

2.) What happens to show up on AM BC on a AM radio does not necessarily mean the same thing will happen on a HF radio on a big antenna.


As a DX'er, and someone who operates low bands, I've NEVER had a good experience living close to 69kV or higher lines. I've been bothered repeatedly by lines even a mile from my past houses when the lines were HV transmission lines. A 69kV line on steel towers in Toledo bothered me in dry weather, and never was resolved. That line was probably 1/4 mile or more away.

In S.Amherst Ohio, a 345 kV line about a half mile west of me raised my west noise floor by 10-15 dB on all bands. Even though Ohio Edison worked on that line and did ten's of thousands of dollars worth of work, it never was resolved.

In Rockdale county GA, a large line two miles from me raised my SW noise floor several dB.

I think the real answer is how much that line bothers you would depend on luck, and how you operate. If you work weak signal work, I'd find a different location. 500 feet is far too close. If you work local ragchews, 500 feet would probably not be an issue.

One thing for sure, in today's deregulated pro-corporate climate, if the line ever develops a problem, you can almost forget about getting it resolved. Don't think for a second that because it is clean on an AM radio one day, it will be that way another hour or another day.

73 Tom
Logged
KI4SDY
Member

Posts: 1452




Ignore
« Reply #6 on: February 07, 2012, 06:17:51 AM »

From a financial standpoint, don't buy it! Even though the "radiation" issue from power lines has proven to be as false as human caused "global warming," the property will never be worth what you paid for it. A prospective buyer will take one look at the power lines and say no, or his wife will! Further, you will have to look at the ugly power lines for the rest of your life and listen to them on your radios.  Shocked

If you are asking these questions, you already know that it is a bad idea that you are trying to rationalize.  Wink
« Last Edit: February 07, 2012, 08:01:42 AM by KI4SDY » Logged
WB2WIK
Member

Posts: 20603




Ignore
« Reply #7 on: February 07, 2012, 08:49:22 AM »

I'd avoid that particular site if I could.

200' high tension towers and their lines still look big and ugly from 500' away, and real estate values due only to that visual impact will probably never be as good as places farther away from the lines where they're not so visible.

Of course, we can't see the particular property you mean; if it's a heavily treed area so when you stand on your lot you can't even see the HT towers and lines, then that's probably a good thing and the "visual impact" will be almost nothing.
Logged
ONAIR
Member

Posts: 1744




Ignore
« Reply #8 on: February 07, 2012, 08:52:31 AM »

  Good points.  The possible noise issue can also change depending on the weather.  Even a tiny bit of noise can wipe out a QSO with a faint signal.  If you have enough green stamps to buy a piece of land and build your own new home on it, treat yourself nice and get some property high on a hill, or even on a mountain!  Hey, we hams only pass this way once, so why not enjoy a little altitude while you're here?  Smiley
Logged
AE5QB
Member

Posts: 269




Ignore
« Reply #9 on: February 07, 2012, 09:47:02 AM »

Hello!  Those who poo-poo the property fail to realize that those portentially (not given) depressed realestate prices will also work in your favor.  If the value in the area has not already factored in the power lines, you will have some bargaining power.  It may be an opportunity for you to get a great deal on the property.

Safety wise a good rule of thumb is no power lines within twice the height of your tower, antenna, or any wires that could snap and go that direction.  The noise may or not be an issue.  You roll the dice and take your chances.

Good luck in your decision.
Logged
KI4SDY
Member

Posts: 1452




Ignore
« Reply #10 on: February 08, 2012, 05:59:06 AM »

"It may be an opportunity for you to get a great deal on a property."

If I owned this property, it would be because some relative left it to me in a will. If they did, and they were my relatives, I can guarantee you that the power lines were not there when they bought the property.

Stuck in that situation, I would try to sell it to a blind guy who was not a ham radio operator cheap! It would be my only hope of getting rid of it.  Sad
« Last Edit: February 08, 2012, 05:47:53 PM by KI4SDY » Logged
W3HKK
Member

Posts: 596




Ignore
« Reply #11 on: February 09, 2012, 04:14:58 AM »

Id explore other options.  No telling when power line noise may kick in.

My experience shows you cant just listen on AM radio bcst band to find the noise.  I currrently have  some form of power line arcing over 1000 ft away that at times is quiet on  bcst band but  S9 on 160m.  Other times it can peak on 80 or 40m.  Other times Ive heard S7 noise on 6M but the other HF bands were quiet, as was the AM band.

Go figure.   
Logged
AA4PB
Member

Posts: 12854




Ignore
« Reply #12 on: February 09, 2012, 05:08:43 AM »

I have a mobile on 75/40/20M and drive directly under such a power line on a pretty regular basis and I've never picked up any noise from the lines. Residential lines near my home on the other hand create noise quite regularly. I expect that is because the residential lines are not maintained as well as the 100KV lines and probably don't have as big a margin in terms of insulators, etc. Based on that experience, I would have to disagree with anyone who says the lines will absolutly be a problem for you.

Put a receiver in your car and drive around the area to see if you pick up any noise.
Logged
KR2C
Member

Posts: 19




Ignore
« Reply #13 on: February 09, 2012, 10:42:05 AM »

Behind my property is a pair of High Tension towers.  The closer one is 230KV and the one behind it is 550KV.  I put up a tri-bander on a 40' tower 80' from the closer power lines and my ground mounted vertical is closer than that.  For the most part, the power lines are very quiet.  However, when a weather front comes through then it makes all of HF useless except for the strongest signals.  When this happens, I just have to go do something else.  No sense in fighting it.

This happened last night.  We had a weak front of snow flurries come through and all the bands had a 20/9 noise level.  This morning 20 meters was so quiet that I thought my antenna was disconnected until I found a station on the band.

Look up my call sign on QRZ and put the map in satellite mode to see how close the towers are.  As far as property values go,  I bought a great house for a great price due to the towers.  And as an added benefit, my neighbors are less likely to complain about my antenna farm with the more ugly high tension towers out back.
Logged
W5ER
Member

Posts: 74




Ignore
« Reply #14 on: February 09, 2012, 03:57:57 PM »

You didn't mention how far apart the towers are from each other.  If 300 ft apart and one line snaps and falls then it is now potentially 300 feet closer to you and your children.   When I was an active firefighter we were required to come no closer than twice the open span distance to any involved pole or tower carrying high voltage electrical lines.

I'd pass

Ed
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!