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Why do most Chicago stations transmit with low wattage?

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radio stain
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Why do most Chicago stations transmit with low wattage?

Post by radio stain » Mon Feb 13, 2017 3:13 am

I know their sticks are tall but when I was there WKQX was getting drowned out in the outer suburbs by ESPN Radio out of St. Louis. B 96 was also getting interference from Now 96.3 from St. Louis. I also found all their signals can be choppy at times in most of the suburbs but they can travel pretty far ar times.

Arthur Mometer
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Re: Why do most Chicago stations transmit with low wattage?

Post by Arthur Mometer » Mon Feb 13, 2017 10:59 am

They are supposed to be equivalent in that the 60 dBu contour goes out the same distance on average with lower ERP at the higher height. The FCC has adjusted the model on this over the years. Many stations were able to increase with the new model. Once you get well beyond the line of sight, ERP is the controlling factor in signal strength.
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Re: Why do most Chicago stations transmit with low wattage?

Post by phillyb » Mon Feb 13, 2017 1:16 pm

radio stain wrote:I know their sticks are tall but when I was there WKQX was getting drowned out in the outer suburbs by ESPN Radio out of St. Louis. B 96 was also getting interference from Now 96.3 from St. Louis. I also found all their signals can be choppy at times in most of the suburbs but they can travel pretty far ar times.
St. Louis stations are mainly class C or C1 stations, which means they can run ERPs of up to 100,000 watts. You probably heard them on a day when there was some tropospheric enhancement, but it doesn't take much to boost the Class C stations so that they cover areas which are outside their "normal" coverage contours.

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Re: Why do most Chicago stations transmit with low wattage?

Post by ftballfan » Mon Feb 13, 2017 10:13 pm

Speaking of Chicago stations, I bet there are times Kiss gets interfered with by TCM up near Six Flags. Same with KQX and 101 WIXX.

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Re: Why do most Chicago stations transmit with low wattage?

Post by mtburb » Tue Feb 14, 2017 7:33 pm

This to a lesser extent happens to television signals in that area too...I heard WGN north of the city has to counter interference with another RF19 station in Wisconsin as well as WXMI Grand Rapids closer to the lake (along with, to a lesser-extent, co-channel interference with WOTV Battle Creek).
For three days in January 2017 (15th, 16th, 19th) and one night in September 2017 (22nd), I managed to receive KDKA Pittsburgh from 202 miles away indoors!

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Re: Why do most Chicago stations transmit with low wattage?

Post by cckadlec » Wed Feb 15, 2017 9:37 am

ftballfan wrote:Speaking of Chicago stations, I bet there are times Kiss gets interfered with by TCM up near Six Flags. Same with KQX and 101 WIXX.
Certainly not, on that point. Kiss never gets interfered with by TCM anywhere aside from Kenosha and Racine, but they also have Kiss IBOC from 103.7 about 35 miles away to deal with. Stations from up by Traverse City don't affect anything south of Kenosha just as stations from Green Bay don't affect anything south of South Haven. It's just how it has always been on both sides with lake tropo; though it doesn't include long-distance tropo openings. WIXX also does not interfere with Chicago. It's actually not that common at all. It sometimes comes in again, toward Kenosha, but it's underneath everything else and only usually heard by someone who specifically is listening for it. But Chicago has height and they get out a long distance, including here in West Michigan.

You can see my Zion bandscan to compare.
[ Radio and weather geeks, beware! Coastal tropo studies and the Seoul AM Radio Listening Guide documentary at http://www.beaglebass.com/dxTuner: Grundig G8 • Location: Fremont, Mich. / 101 mi. ene of Milwaukee ]

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Re: Why do most Chicago stations transmit with low wattage?

Post by 48125er » Wed Feb 15, 2017 1:06 pm

I've always found it interesting that have such low wattage yet can sometimes make it 50 miles inland in Michigan.

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Re: Why do most Chicago stations transmit with low wattage?

Post by cckadlec » Wed Feb 15, 2017 1:20 pm

That's because of tropospheric conditions over the water, keeping in mind that station power is absolutely irrelevant in tropo conditions over water at least until the opposite shore. (See my Cape Breton bandscans for dinky stations that cross water with no signal loss, such as 43 watts at 222 miles and 58 watts at 239 miles). After reaching land, it's a different story, but because Chicago stations start out at high elevation, tropo a few thousand feet above the lake, which is often common in the warm months, sends the signal to the opposite shore before it gradually it reaches the ground, which isn't immediately, so a station from the Hancock Tower that gets caught up in tropo over the water may reach Michigan entirely unhampered with little to no signal loss, then extends across the land as if it were originating from the beach. Then you have a station with its usual coverage area of 50-60 miles, therefore 50 miles inland.
[ Radio and weather geeks, beware! Coastal tropo studies and the Seoul AM Radio Listening Guide documentary at http://www.beaglebass.com/dxTuner: Grundig G8 • Location: Fremont, Mich. / 101 mi. ene of Milwaukee ]

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Re: Why do most Chicago stations transmit with low wattage?

Post by audiophile » Wed Feb 15, 2017 2:55 pm

There must be at least inverse field loss - basically same signal as line-of-sight.
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Re: Why do most Chicago stations transmit with low wattage?

Post by Arthur Mometer » Wed Feb 15, 2017 9:58 pm

audiophile wrote:There must be at least inverse field loss - basically same signal as line-of-sight.
I agree. And if you are at higher elevation inland, you might have LOS. A high ERP signal will always be stronger than a low ERP signal along the same path. People who DX in airplanes (these people are arrested when they deplane, so don't try this at home) have also told me that the Low ERP/High HAAT signals like Hancock and Sears Tower (heritage name) don't get far at 30000 feet compared to 50 kW and 100 kW stations from elsewhere, like say WBBM-FM vs. WLXT.
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Re: Why do most Chicago stations transmit with low wattage?

Post by audiophile » Thu Feb 16, 2017 5:48 am

I heard WOMC clearly in airplane over West Virginia, Kentucky and Ohio on my phone, that uses the headphone cable as an antenna.

The phone was in airplane mode, so I don't believe it was a problem using the fm receiver.
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Re: Why do most Chicago stations transmit with low wattage?

Post by cckadlec » Thu Feb 16, 2017 6:02 am

I have DXed in airplanes many times, over Mexico, Russia, Japan, Korea, and the US and Canada. It is quite widely tolerated. I have friends who have done so using portable TVs and SDR software among others. As long as you have a window seat, you can pick up the stations (only from cities on your side of the plane) at about 200-250 miles on average. I have plenty such recordings. I've long since given up on airplane DX as most of my flights I take fly over the Arctic Ocean and Siberia, neither being great areas for much other than low powered stations which aren't heard up high. And totally -- the high-powered ones like 100kw are especially strong and common up high. Same with AM when it comes to propagating around the world. The big ones in Asia like my old local HLAZ on 1566 are crappy at ground level in the country but because of their high power, easily span the globe, but while the low powered ones like 1 or 10kw stations are easy to hear at pretty good distance in Asia, they rarely get out at cross-the-globe distances.

So power makes a difference... in certain circumstances, especially those outside the lower troposphere.
[ Radio and weather geeks, beware! Coastal tropo studies and the Seoul AM Radio Listening Guide documentary at http://www.beaglebass.com/dxTuner: Grundig G8 • Location: Fremont, Mich. / 101 mi. ene of Milwaukee ]

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Re: Why do most Chicago stations transmit with low wattage?

Post by Arthur Mometer » Thu Feb 16, 2017 7:14 am

cckadlec wrote:That's because of tropospheric conditions over the water, keeping in mind that station power is absolutely irrelevant in tropo conditions over water at least until the opposite shore. (See my Cape Breton bandscans for dinky stations that cross water with no signal loss, such as 43 watts at 222 miles and 58 watts at 239 miles). After reaching land, it's a different story, but because Chicago stations start out at high elevation, tropo a few thousand feet above the lake, which is often common in the warm months, sends the signal to the opposite shore before it gradually it reaches the ground, which isn't immediately, so a station from the Hancock Tower that gets caught up in tropo over the water may reach Michigan entirely unhampered with little to no signal loss, then extends across the land as if it were originating from the beach. Then you have a station with its usual coverage area of 50-60 miles, therefore 50 miles inland.
This what you talkin' about, Willis?

https://latitudetravels.net/2015/11/17/ ... f-chicago/

I would have to see Field Strength Measurements of collocated stations, with different ERP, diplexed into the same antenna, or measurements made with the exciter, full power, or different power levels from the same station, to be convinced that ERP doesn't make a difference.

I DO believe that a very low ERP signal can reach the opposite shore. I don't believe that it can possibly be the same FI as a high ERP signal from the same source on the same frequency over the same path. At best you have a very imperfect waveguide effect. There has to be some loss though. The low ERP signal from a different source, height, frequency, path could be focused to a greater power density at a given location. But it has to obey the Laws of Physics.

WLS-TV and WTTW, both at around 316 kW at about 220 miles at the time, around July 4, some time in the early 1970s, was the strongest I ever DXed a Chicago TV station from my location in Genesee County at the time. WGN-TV at 112 kW was way weaker, WBBM-TV and WMAQ-TV were weaker still. If there are records about tropo conditions from back then, check around July 4 from 1970 to 1973.
Last edited by Arthur Mometer on Thu Feb 16, 2017 7:37 am, edited 1 time in total.
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Re: Why do most Chicago stations transmit with low wattage?

Post by cckadlec » Thu Feb 16, 2017 7:34 am

ERP can make a different in signal strength overall. I mean, that can be seen in a station like WBCT. But a dinky station near the water will get out just the same as a powerful one is what I mean. The low power makes little difference assuming there is nothing stronger in its way to interfere.

Mirages and tropospheric propagation do not always coincide. I know this from years of experience with it and from monitoring signals during similar conditions in Ludington, Muskegon, and Grand Haven. But it does depend on which kind of mirage we're talking about. If you're looking at Wegener's blank strip, conditions can be quite nice on the radio. But as often as it happens, it doesn't always lead to radio, TV, or cellphone propagation. Oddly enough.

I've seen the Milwaukee skyline from Muskegon and Grand Haven five times and Chicago (upside-down) from Muskegon once, on the day of the Muskegon photos below. The lights of Kenosha tend to be common from Grand Haven, especially in April, and Port Washington Light is pretty common from Muskegon around the same time, though I've seen it a few other times during ideal conditions. But while cellphone signals travel easily during this, it wasn't so reliable with FM during these instances. Light and radio waves seem to travel a bit differently. 16 years studying this crap and the signals not coinciding with the mirages (in the ways I had expected anyway) was one frustrating realization. In the end, it really depends between which two points the inversion lies/connects. In the blank strip (seen in the daytime below and at sunset; the sun sets behind the strip which casts a shadow), only water and air is being refracted, hence it being "blank," meaning it isn't stretching to the opposite shore.

And a note relating to your 1970s catches: I deal only with marine tropo. Long-haul events over land like that, I don't pay any attention to as it's not my interest. If it's over water or enhanced particularly by the water, I have years of experience. I leave the over-land stuff to anyone else. :D

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Last edited by cckadlec on Thu Feb 16, 2017 7:50 am, edited 1 time in total.
[ Radio and weather geeks, beware! Coastal tropo studies and the Seoul AM Radio Listening Guide documentary at http://www.beaglebass.com/dxTuner: Grundig G8 • Location: Fremont, Mich. / 101 mi. ene of Milwaukee ]

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Re: Why do most Chicago stations transmit with low wattage?

Post by Arthur Mometer » Thu Feb 16, 2017 7:49 am

Show me the Fata Morgana Pictures and FM Field Strength data of different ERP from the same exact time, and show me "normal" pictures and Field Strength data. It HAS tho obey the Laws of Physics. It will refract differently at different frequencies, an extreme prismatic effect. Perhaps it is refracted to a different height AGL where the FM signals are enhanced, so we have Fata Morgana at ground level and FM signal enhancement at some height AGL. The refraction and EM energy are going somewhere regardless of frequency.
"I'm meteorologist Arthur Mometer."

"Those of you who think you know everything are very annoying to those of us who do."

"Lies have to be repeated and repeated to be believed. Truth stands on its own merit."

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Re: Why do most Chicago stations transmit with low wattage?

Post by cckadlec » Thu Feb 16, 2017 7:54 am

Very true. There are so many different factors in it, like elevation, how it appears as viewed from our own eyes (as the mirages appear drastically different from the beach level and 200-300 foot dune-top level, it can be confusing). Furthermore, it's tough to monitor signals higher up that the highest possible dunes. It's a real pain. The signal obviously goes somewhere, but to know how far the conditions go out into the water unbroken is also very difficult. If only these things could be easily determined... :(

Of course, I deal with the weather side of things by monitoring signals to see how the weather conditions impact them. Once you're into engineering, physics, etc., I'm out. Never been interested in it, nor do I understand it. It's about the signals that are received and their location, height, etc., in comparison to weather conditions at the time between the two points. If I had a partner in crime with the engineering knowledge, things may have worked out differently before I moved on to other projects after 16 years.
[ Radio and weather geeks, beware! Coastal tropo studies and the Seoul AM Radio Listening Guide documentary at http://www.beaglebass.com/dxTuner: Grundig G8 • Location: Fremont, Mich. / 101 mi. ene of Milwaukee ]

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Re: Why do most Chicago stations transmit with low wattage?

Post by k8jd » Fri Mar 10, 2017 2:20 pm

When I read the subject line I was amazed because I immediately thought of ; WSCR, WGN, WBBM, WLS, WMVP and WYLL ALL 50,000 W and then there is ; WNVR 27 kW, WRTO 20 kW, and WVON 10 kW !
Then I found out it's about the FM stations who mostly moved to the Sears tower where the extreme antenna height makes the FCC license lower ERP !

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Re: Why do most Chicago stations transmit with low wattage?

Post by mtburb » Fri Mar 10, 2017 3:03 pm

Speaking of WBBM, remember when they originally signed on their digital television transmitter on RF3? Thousands of people couldn't even get it and yet they couldn't increase power because then thousands of people in downtown Chicago would loose cable service.

Not to mention that wiping away any ability to DX WWMT in areas closer to downtown Chicago at all.
For three days in January 2017 (15th, 16th, 19th) and one night in September 2017 (22nd), I managed to receive KDKA Pittsburgh from 202 miles away indoors!

My tropo station reception reports: https://www.rabbitears.info/dxlocation.php?id=403

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Re: Why do most Chicago stations transmit with low wattage?

Post by cckadlec » Fri Mar 10, 2017 6:58 pm

Before digital, Chicago analog signals would regularly crush Michigan ones here in Fremont. WGN would cause such severe CCI on 9 from Cadillac that both were unwatchable, though WGN would usually win out. And PBS 10 in Milwaukee started out on digital channel 8, which would regularly wipe out WOOD on analog, which is the reason for their lakeshore translator stations. But we're in a more unique area. A few days ago, I started driving to GR for work and here in town, the dial was all Chicagoland with RDS. Get a mile south of town and almost everything was gone. Just regular happenings here. And same with Milwaukee. Being line of sight makes it pretty easy.

I do remember about WBBM not being able to be received around the city (all the while thinking what a bad idea digital is). We lost 90% of all our channels in the digital switch to the point we could barely watch TV at all. When we lost TMJ, we had no NBC (or at least spotty at best), and FOX 6 changing to a directional pattern after the switch left us with no FOX affiliate, though 9 up north had a great digital signal that got us a new CBS, and of course, WZZM is 10 miles away, so no issues there. We'd later give up and get cable because even now, if you want to watch anything aside from WGVU or WZZM, you gotta move the antenna and find the exact number of degrees to watch anything. When you're switching between shows, it's ridiculous. DX-wise, I haven't touched TV since then and even during the biggest tropo openings, I'd still barely get more than a few signals.
[ Radio and weather geeks, beware! Coastal tropo studies and the Seoul AM Radio Listening Guide documentary at http://www.beaglebass.com/dxTuner: Grundig G8 • Location: Fremont, Mich. / 101 mi. ene of Milwaukee ]

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Re: Why do most Chicago stations transmit with low wattage?

Post by Radio Fanatic » Tue Apr 18, 2017 11:11 am

“Superior mirages over Chicago skyline now appearing”
April 18, 2017
http://www.mlive.com/weather/index.ssf/ ... icago.html

cckadlec wrote:
Thu Feb 16, 2017 7:34 am
Mirages and tropospheric propagation do not always coincide. I know this from years of experience with it and from monitoring signals during similar conditions in Ludington, Muskegon, and Grand Haven. But it does depend on which kind of mirage we're talking about. If you're looking at Wegener's blank strip, conditions can be quite nice on the radio. But as often as it happens, it doesn't always lead to radio, TV, or cellphone propagation. Oddly enough.

I've seen the Milwaukee skyline from Muskegon and Grand Haven five times and Chicago (upside-down) from Muskegon once, on the day of the Muskegon photos below. The lights of Kenosha tend to be common from Grand Haven, especially in April, and Port Washington Light is pretty common from Muskegon around the same time, though I've seen it a few other times during ideal conditions. But while cellphone signals travel easily during this, it wasn't so reliable with FM during these instances. Light and radio waves seem to travel a bit differently. 16 years studying this crap and the signals not coinciding with the mirages (in the ways I had expected anyway) was one frustrating realization. In the end, it really depends between which two points the inversion lies/connects. In the blank strip (seen in the daytime below and at sunset; the sun sets behind the strip which casts a shadow), only water and air is being refracted, hence it being "blank," meaning it isn't stretching to the opposite shore.

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