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Air Traffic Monitoring => Listener Forum => Topic started by: blizzard242 on April 12, 2006, 01:46:12 AM

Title: Does bad weather make for better radio?
Post by: blizzard242 on April 12, 2006, 01:46:12 AM
I find that radio reception comes in much better as bad weather approaches. I live near Port Huron Michigan, and I picked up New York Center for a second. Does ATC increase their broadcasting string as bad weather approaches. I know water vapor absorbs radio-frequency so do they increase there power to make up for the loss?
Title: Does bad weather make for better radio?
Post by: Lezam on April 12, 2006, 08:36:16 AM
It seems like that to me also. When it rains it comes in clearer. But the problem for me is that when there are 30 mph winds the reception decreases very significantly. Anyone know the scientific stuff?  :D
Title: Does bad weather make for better radio?
Post by: MIAMIATC on April 12, 2006, 09:08:19 AM
Me thinks it is the density of the air. When the air is humid and loaded w/moisture the air is less dense than cold and dry air hence the radio waves have less effort to travel. By the way which sector were you pickig up if I may ask ?
Title: Does bad weather make for better radio?
Post by: dave on April 12, 2006, 09:21:18 AM
Quote from: Lezam
It seems like that to me also. When it rains it comes in clearer. But the problem for me is that when there are 30 mph winds the reception decreases very significantly. Anyone know the scientific stuff?  :D


These are the classic symptoms of power line noise.  Power line noise can severely hamper reception in the low VHF range (aviation band).

Dave
Title: Does bad weather make for better radio?
Post by: dave on April 12, 2006, 09:22:17 AM
Quote from: NYARTCCFAN
Me thinks it is the density of the air. When the air is humid and loaded w/moisture the air is less dense than cold and dry air hence the radio waves have less effort to travel. By the way which sector were you pickig up if I may ask ?


Sounds like a temperature inversion.  You can get enhanced reception during a temperature inversion.

Dave
Title: Does bad weather make for better radio?
Post by: JetScan1 on April 12, 2006, 09:47:31 AM
Google "tropospheric ducting" and you'll find a lot of good information.

http://www.angelfire.com/sc/scannerpost/tropo.html

http://homepage.ntlworld.com/booty.weather/metinfo/ducting/ducting.html

http://home.cogeco.ca/~dxinfo/tropo.html

On a few very rare occasion I have recieved Center controllers loud and clear transmitting from over 100 nautical miles from my location.
 
DJ
Title: Does bad weather make for better radio?
Post by: blizzard242 on April 12, 2006, 01:49:52 PM
Quote from: NYARTCCFAN
Me thinks it is the density of the air. When the air is humid and loaded w/moisture the air is less dense than cold and dry air hence the radio waves have less effort to travel. By the way which sector were you pickig up if I may ask ?


Sorry I dont know what scector it was, I could only hear New York Center Roger.
Title: Does bad weather make for better radio?
Post by: Lezam on April 12, 2006, 04:58:02 PM
Quote from: dave

These are the classic symptoms of power line noise.  Power line noise can severely hamper reception in the low VHF range (aviation band).
Dave


Whats power line noise? Is there a way to fix it?
Title: Does bad weather make for better radio?
Post by: PHL Approach on April 12, 2006, 05:17:23 PM
Quote from: blizzard242

Sorry I dont know what scector it was, I could only hear New York Center Roger.


Do you remember what frequency?
Title: Does bad weather make for better radio?
Post by: PHL Approach on April 12, 2006, 05:20:29 PM
Quote from: Lezam
Quote from: dave

These are the classic symptoms of power line noise.  Power line noise can severely hamper reception in the low VHF range (aviation band).
Dave


Whats power line noise? Is there a way to fix it?


It's just interference, all man made properties. PC's, general electronics, and our nations power grid give off heavy amounts of interference. The big one as Dave mentioned is power lines, they surround us all 24/7. Not much you can do, atleast I think it's to powerful to do anything. Dave?
Title: Does bad weather make for better radio?
Post by: dave on April 12, 2006, 05:29:26 PM
One thing you can do is call your local power company and find out if they have an RFI (Radio Frequency Interference) division.  Usually if there is a problem on your street (or nearby) then it also behooves the power company to fix the issue, since it likely affects the efficient transfer of power down the lines as well.  Some of the problems they have are loose insulator hardware, insulator materials that are breaking down, etc.  Contact the RFI folks and tell them what you are observing.

Whether your company has an RFI group or not, the best thing you can do is try and locate the pole causing the interference.  This is more complicated than I can describe right now in this posting, but the process consists of you walking and/or driving around with a handheld or mobile receiver to narrow odwn the source of the interference.  If you can identify the pole then they can usually fix it.  It will be especially easy if you see any arcing on the pole.

If the issue is being caused by high tension distribution lines then the fix may be difficult.  It has been my experience that it is far more complicated to fix those issues since they frequently have to shut down or transfer power between high voltage distribution lines, which can be complicated.  High tension lines are usually not the cause of these types of problems since they are typically much better maintained.  But never say never.

Hope this helps.  There are some great ham radio articles on this someone around the net.  Google your way around.

Dave
Title: Does bad weather make for better radio?
Post by: Lezam on April 16, 2006, 12:32:01 AM
I have a power pole directly ahead of me. Actually, from my antenna to jfk looking straight, its dead ahead. Literally....
Title: Does bad weather make for better radio?
Post by: digger on April 16, 2006, 01:16:18 AM
Quote
The big one as Dave mentioned is power lines, they surround us all 24/7. Not much you can do, atleast I think it's to powerful to do anything.


On the other hand, you should see what happens when there's an ELT transmitting somewhere near a power line. The signal can travel along the line, making it very hard to locate. Drives the Civil Air Patrol absolutely nuts...
Title: Does bad weather make for better radio?
Post by: Tomato on April 22, 2006, 12:40:25 AM
Thisi reminds me of back in the day when you built those AM Crystal Radio kits... great kit, fun, and mentinoed that you may get better reception during the early hours, rainy weather, yadda yadda... good times!  :)