Radio Signals this morning
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Railroad
Routinely Derailed
Madam, I find your unction reminiscent of what one would detect in a squirarchy, singularly outlandish, and in fact a retrocession from the vernacular.jazz lady said:My abject extenuations for such iniquitous, odious and ignoble comportment.
In other words, you go, girl!!!!
Railroad
Routinely Derailed
Huh! I'll try, but I'm no expert. I know an engineer or two that would be telling me to quit while I'm ahead (I'm not an engineer).K_Jo said:Tell us more, Mr. Science!
The first part of this is the atmospheric effect I referred to as "ducting." As with any impure liquid, the amount of impurities isn't distributed evenly throughout the volume of the atmosphere. The combination of humidity, conductive dust particles, polarization of ion concentrations, and probably some other stuff can combine to make areas of the atmosphere more conductive than others. The size and shape of the unusually conductive area governs the frequency of signal that will follow it. So some frequencies are more susceptible to a given duct formation than others.
Over a body of water where evaporation causes the water to release ions and salts into the air above it, the ducting effect is much more common than in a dry area, because these things released by the water are (as mentioned before) distributed unevenly.
So you can imagine a big invisible pipe for electromagnetic energy forming in the atmosphere. This is why we (around here, anyway) can frequently hear Jose in Havana on his 5-watt CB radio. That signal is (a) not strong enough and (b) the wrong frequency to normally make it here, but it does because of ducting.
Okay, the second part of the answer is all about power. A radio frequency transmitter develops and transmits a fixed amount of power out through the antenna. In an ideal situation where the antenna is in a vacuum (no atmosphere), the antenna's shape will cause it to radiate the energy in a very predictable fashion. You've probably seen depictions of circles spreading out and away from a radio antenna in cartoons. Not a bad way to show it.
But in the real world, things like ducting and atmospheric absorption start changin the radiation pattern from the antenna, causing areas of greater and lesser energy (referred to as field strength).
In ducting and in atmospheric loss, we have a problem of the power budget.
If the transmitter transmits 5 watts of power, and 3 watts of it cover the best areas for reception, the other 2 watts are used up by ducting and atmospheric loss.
But if ducting and atmospheric loss are really bad someday, and they're stealing 3 watts of energy, you will only have 2 watts left for everything else - because 5 watts is all you get to do the job.
With solar activity and electromagnetic storms, all bets are off. Solar radiation disrupts the ionosphere and radio propagation goes to poop worldwide. But that's another story!
B
baswm
Guest
tlatchaw said:105.1 WAVA worked just fine!
('Course not everybody likes listenin' to preachers in the morning!)
This morning a delmarva country station kept cutting in and out until I got closer to work.
No problem, They usually update the report once a week or so. I used to always get on the CB so I kinda had to figure some of that stuff out. It's a funny feeling to talk to someone in Canada, Florida, Georgia, Washington, and Texas all at the same time from your truck.Railroad said:Excellent! Thanks, Magnum!!
ingoboingo:
That’s what I would have told you (I am an engineer).Railroad said:
The most likely cause of the “interference” that we have had the past couple of mornings is more of an issue with temperature and inversion layers within the atmosphere and not impurities in the air. Days when we have a cold dry air mass the likelihood for ducting is significant when a warm air mass moves our way. If that warm layer is such that it gets sandwiched between two cold dry masses a duct is developed that can extend the range of a transmitter site by up to a hundred miles or more.
Today, I was able to identify the station that was interfering with WSMD 98.3; it was being extended from Clarksville, VA (south center of the state on the NC line). Matching that with weather data an inversion layer was apparent at the 15,000-foot level and extended to the 18,000-foot level with temperatures about 10 degrees higher then the layers immediately above and below it. This formed the duct that brought the interference up here that was simply more powerful then the local station's direct broadcast. As the day wears on and there are other variations with the temperature aloft the ducting will subside and normal reception will be once again available.
Ed Zachary
New Member
I say that aliens are intercepting the radio signals and trying to re-route communications so that we are in a weakened state. But I'm not an engineer either.
Kens logical comments make much more sense though.
Kens logical comments make much more sense though.
SouthernYankee
New Member
Ken King said:
(I am an engineer) that is funny, did you get it from a Cracker Jack box or from one of those Internet sites? How much was it to attend without going to class, then claim a degree? I guess there is a sucker borne every day. Where can you use the degree? How many graduated with you? Wasn’t there a story in the paper awhile back about people getting degree’s from places that claimed to be associated with Universities but in reality they were in some buildings basement printing up diploma’s 100’s at a time. Please enlighten use on where your degree is from.