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WSB 95.5 Reception

SomeRadioGuy

SomeRadioGuy

How is that possible? Wow! The most I’ve DXed on FM/TV is WCTE TV 22 Cookeville from Memphis and that was about 350 miles away. I would think there’s got to be several other 95.5 FMs that would interfere with the line of sight before getting to WSBB.
 
RadioDoogie said:
How is that possible? Wow! The most I’ve DXed on FM/TV is WCTE TV 22 Cookeville from Memphis and that was about 350 miles away. I would think there’s got to be several other 95.5 FMs that would interfere with the line of sight before getting to WSBB.
Click to expand...

It is very common, before Atlanta had all the move in's. I would always get stations, especially this time of year. That were from North Dakota, SD, Montana, Nebraska, Oklahoma, Texas. One that I really remember was 103.7 from Winner, SD, was clear as a local for about 4 hours.

It is called Tropospheric propagation. Does not matter how many stations are on one frequency.
 
BIGSTICK said:
It is very common, before Atlanta had all the move in's. I would always get stations, especially this time of year. That were from North Dakota, SD, Montana, Nebraska, Oklahoma, Texas. One that I really remember was 103.7 from Winner, SD, was clear as a local for about 4 hours.

It is called Tropospheric propagation. Does not matter how many stations are on one frequency.
Click to expand...

Not tropo. Tropo is short distance 100-200-300 more ground based

eskip is 800-900-1000-1100-1200 miles
 
IMHO the worst atmosphere effect in FM is a form of “tropo ducting” where moisture between the antenna (usually 900 ft or more) and the ground “blocks or reflects” the local signal (less than 10 miles from the tower) and “bounces” it a couple of hundred miles away. This can happen to stations on the American Gulf Coast. There was a post several years ago about a station actually switching to their back up facilities at lower high because they couldn’t pick up the station at the studio. I personally thought circular polarization was supposed to fix this (and have better building penetration too), but I guess the atmosphere sometimes does things that can’t be engineered for. I do know from personal experience at Eglin AFB sometimes the severe fog caused all kinds of issues with Trac 97 line of site shots over water (swamps and bays) during JCS exercises during the early 1970’s. But these were 1 watt shots that used really sensitive receivers* and a signal comparer to pick up signals as low as -102 dBm. which was pretty good at the time for equipment that bounced around the countryside in the back of a ton and a quarter jeep/pickup.

Here are my to favorite sources which show where FM can behave “badly”

http://aprs.mennolink.org/

http://www.dxinfocentre.com/tropo.html

*I could trouble shoot and repair the receivers using the test points and the manual, but the Trac 97A used a weird “tunnel diode” circuit in the receiver which I really never understand of how it worked. I do know that the tunnel diodes were very sensitive to static charges.
 
That's some incredible DXing, SomeRadioGuy.

I'm interested to know of the receiver used and if you have a specific antenna mod, or is it stock?
 
Tropo can also cause big problems with 900 MHz STL especially near the coast. Some stations have two 900 MHz antenna on the same tower (high and low) and switch to the lower antenna during a tropo opening. The signal from a very high antenna can bounce off the inversion top causing a big STL path loss. Some call spring/early summer tropo season because of all the problems on the FM band. I remember one station employee claiming that they were receiving a co-channel station in the station parking lot. Hard to believe unless they were really in their antenna null during a really bad inversion (makes a good story however). Of course bad for the station owners is good to the DX folks.
 
Ray said:
Tropo can also cause big problems with 900 MHz STL especially near the coast. Some stations have two 900 MHz antenna on the same tower (high and low) and switch to the lower antenna during a tropo opening. The signal from a very high antenna can bounce off the inversion top causing a big STL path loss. Some call spring/early summer tropo season because of all the problems on the FM band. I remember one station employee claiming that they were receiving a co-channel station in the station parking lot. Hard to believe unless they were really in their antenna null during a really bad inversion (makes a good story however). Of course bad for the station owners is good to the DX folks.
Click to expand...

A good example of diversity reception was KBIG 740 at Avalon, Catalina Island, 26 miles (like the song) off the CA coast. They had two microwaves with two reception antennas at different heights on Catalina. When there were inversion layers... fairly common with the studio on land and a bunch of water in the middle... it would pick the best one.
 
RadioDoogie said:
How is that possible? Wow! The most I’ve DXed on FM/TV is WCTE TV 22 Cookeville from Memphis and that was about 350 miles away. I would think there’s got to be several other 95.5 FMs that would interfere with the line of sight before getting to WSBB.
Click to expand...

As some of the others have noted, it’s either eSkip or tropospheric ducting. While it is possible to get tropo over more than the 300 or so miles the other poster mentioned, Atlanta to Wyoming is almost certainly going to be eSkip.

As a teenager, I once got WCGY 93.7 out of suburban Boston in Oklahoma. It was even covering up KISR 93.7. I also got WRNS-FM 95.1 and WZFX 99.1 in Oklahoma, the latter of which completely covered KMAG 99.1. Granted, I was on the fringe areas of the two semi-locals' signal contours, but a good car radio or home stereo could usually get both of them at my location. I got those three stations exactly once, which means it was almost certainly eSkip. I only got WCGY for about 5 minutes (again, a good sign of eSkip), and I got the other two for about 30 minutes. Typically, stations you get via tropo return occasionally as tropo is a fairly common phenomenon, and you get them longer than you do those you get via eSkip.
 
If ths signal was a rimshot into the market and the cluster studios were downtown, I can see the possibility of getting a distant co-channel signal in the parking lot (it wasn't specified he was pulling into the transmitter site)




Ray said:
Tropo can also cause big problems with 900 MHz STL especially near the coast. Some stations have two 900 MHz antenna on the same tower (high and low) and switch to the lower antenna during a tropo opening. The signal from a very high antenna can bounce off the inversion top causing a big STL path loss. Some call spring/early summer tropo season because of all the problems on the FM band. I remember one station employee claiming that they were receiving a co-channel station in the station parking lot. Hard to believe unless they were really in their antenna null during a really bad inversion (makes a good story however). Of course bad for the station owners is good to the DX folks.
Click to expand...
 
gr8oldies said:
If ths signal was a rimshot into the market and the cluster studios were downtown, I can see the possibility of getting a distant co-channel signal in the parking lot (it wasn't specified he was pulling into the transmitter site)
Click to expand...


A friend of mine who was an engineer for a group of stations in Hannibal, MO/Quincy, IL up until a few years ago called me one summer and told me his 900mhz STL for one station was getting hammered by some public radio station several hundred miles away
 
secondchoice said:
IMHO the worst atmosphere effect in FM is a form of “tropo ducting” where moisture between the antenna (usually 900 ft or more) and the ground “blocks or reflects” the local signal (less than 10 miles from the tower) and “bounces” it a couple of hundred miles away. This can happen to stations on the American Gulf Coast. There was a post several years ago about a station actually switching to their back up facilities at lower high because they couldn’t pick up the station at the studio. I personally thought circular polarization was supposed to fix this (and have better building penetration too), but I guess the atmosphere sometimes does things that can’t be engineered for. I do know from personal experience at Eglin AFB sometimes the severe fog caused all kinds of issues with Trac 97 line of site shots over water (swamps and bays) during JCS exercises during the early 1970’s. But these were 1 watt shots that used really sensitive receivers* and a signal comparer to pick up signals as low as -102 dBm. which was pretty good at the time for equipment that bounced around the countryside in the back of a ton and a quarter jeep/pickup.

Here are my to favorite sources which show where FM can behave “badly”

http://aprs.mennolink.org/

http://www.dxinfocentre.com/tropo.html

*I could trouble shoot and repair the receivers using the test points and the manual, but the Trac 97A used a weird “tunnel diode” circuit in the receiver which I really never understand of how it worked. I do know that the tunnel diodes were very sensitive to static charges.
Click to expand...

Based on this site, in order to receive a station far away does the heavy tropo activity have to be occurring both where you are and where the station you’re DXing is or can it be just one area that is experiencing the tropo and not the other. If it is one or the other, will there be better reception if heavy tropo activity is in my area or the station I am DXing’s area?
 
RadioDoogie said:
Based on this site, in order to receive a station far away does the heavy tropo activity have to be occurring both where you are and where the station you’re DXing is or can it be just one area that is experiencing the tropo and not the other. If it is one or the other, will there be better reception if heavy tropo activity is in my area or the station I am DXing’s area?
Click to expand...


Usually “tropo” is a relativity “local” event. Maybe 200 miles max (your mileage may vary). Usually the transmitter needs to be in or in line of sight to area with heavy tropo conditions. Your best chance of pick up a “tropo” signal is to be within or line of sight to the effect due to the line of sight nature of FM.

E skip on FM is different. The “old” AM simplified explanation “the ozone level “(ionosphere) acting like a mirror to reflect signal” can happen on FM too, just not every night like AM. My personal E skip record is Scoot City KS 94.5 KSKL at a campground in Western North Carolina on a perfectly clear sunny 55 degree day. The car radio found it. It was one of only 4 “stops” on FM scan.

I have not read any studies where somebody tried set up an experiment to see how far you could DX a 1 watt 900Mhz link during tropo conditions. The DOD most likely has done this in the past and I doubt still are classified. There has been some really long “troposcatter” microwave shots over water with “billboard” size antennas really powerful transmitters which I was trained to work on when I was in the Air Force.* You would most likely have to look pre 1970 before the widespread use of satellite communications for more info. For commercial AM & FM reception go to the DX part of this site.** There are folks who do ridiculously long distant reception on a regular basis with really nice receivers and antennas.

*https://www.subbrit.org.uk/features/ace-high-nato-communications-system/

** https://www.radiodiscussions.com/forumdisplay.php?769-DX-and-Reception
 
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