skip heard from aberdeen ms in louisiana!

[twolf816]

2 min ago i heard skip on 151.0700

"aberdeen emergystat, prairie; assist lifemed (or lifenet) 1-car 10-50 on hale quarters rd in the big curve. person hit a tree. off of homestead in prairie. 22:29"

"were gonna put north mississippi air on standby. 22:35"

i looked it up and it looks like i got the right area. ive heard this before and will try to get a recording next time. can someone confirm?


edit: i have a recording if anyone is interested

 

[INDY72]

Niceeeeeee one! Great catch! Now if you get lucky eneough to catch tones on that... itll be even sweeter!

 

[nexus]

What you experienced is called tropo DUCTING, not skip.

Ducting is an increase in range that an electromagnetic wave will travel due to a temperature inversion of the lower atmosphere. The temperature inversion forms a channel or waveguide (duct) for the waves to travel in, and they can be trapped. The ducting phenomena is frequency sensitive. The thicker the duct, the lower the minimum trapped frequency.

As hot air masses come in contact with cold air masses it will form a duct. So whenever the weather is going to be making any substantial changes in temp. in your area, or where it will cross over your area be sure to scan the VHF/UHF bands. Ducting effects the higher frequency ranges, 30-300 mHz range generally, which is VHF.

It's most common at night where tempatures change, and early mornings when cold night air masses are coming in contact with hot day time air massess. Usually signals can travel along this ducting for several hundred and thousands of miles. I've personally talked with others on ham radio simplex several states away on just 5 watts of power from a handheld into a base antenna because of this.

If you want to learn more about this check here:

http://home.cogeco.ca/~dxinfo/tropo.html
http://www.astrosurf.org/lombry/qsl-propa6.htm

 

[twolf816]

ok, your talking about a particular kind of skip, its still skip. i really dont care what kind it is, i just think its neat that i can hear something 200miles away. i would like to know if my area could be heard from a great distance. i posted this to possibly let someone know im hearing their ems 250 miles away, not to be corrected with a science lesson. k?

 

[INDY72]

OK guys lets keep it civil... Nexus was just trying to explain the phenomenon correctly.... Skip is usually associated with below 50 MHz, ducting is usually up to 200 MHz, though there is occaisionally UHF, and even 800 ducting...

I have monitored at least three 800 TRS's in Southern LA from near Natchez MS.....

Now whats cool is the ducting that you can fully grab from over 200 miles off, and decode Tones, and hear for several hours.. even days.... Even better is the one time I nabbed TG's on a TRS at least 120 miles away.

One of our listeners monitored the MS State Capitol PD on UHF frm Knoxville TN...... and I once monitored the old Rankin County MS UHF system before they went 800 from Biloxi MS....

Its an interesting phenomenon!

 

[twolf816]

milf, ive been hearing what i thought was just aberdeen, but ive heard other nearby towns in the place of aberdeen emergystat, ever since i owned a scanner for some reason, stronger in the mornings and evenings but i hear it at least once an hour, on all 3 scanners, on 3 different antennas, and all over the 30mile radius of monroe, la. what im wondering is: am i the only one hearing it, like im in a certain "path", or is it like a normal tx brodcast, in a circle.

 

[bassmkenk2508]

while i was doing casual scanning in the 406-420 MHz band, i heard what sounded like TRS control channel. I searched online for the frequency and came up with it being listed under an air force base in Florida. That same night I heard other freq's in the band with traffic containing aeronautical terminology and talk. It could have been something closer in the southeast region, knowing that freqs in this band aren't typically found in the FCC database and a govt location could have just begun use of it.

I was also amazed when i heard Hattiesburg TRS here at home. That was neat too!

 

[INDY72]

yes ducting usually has "Paths" it follows... example- Hammond LA area up through say Brookhaven, MS area... its a nice constant path there...

Also sayyyy McComb, MS, through most of Southern LA.

 

[nexus]

while i was doing casual scanning in the 406-420 MHz band, i heard what sounded like TRS control channel. I searched online for the frequency and came up with it being listed under an air force base in Florida. That same night I heard other freq's in the band with traffic containing aeronautical terminology and talk. It could have been something closer in the southeast region, knowing that freqs in this band aren't typically found in the FCC database and a govt location could have just begun use of it.

I was also amazed when i heard Hattiesburg TRS here at home. That was neat too!

Stennis Space Center operates a TRS in that frequency range, and they happen to have a patch with unicom 122.8000 and a patch with the stennis international airport frequncy. So any time someone keys up on that frequency it broadcasts on it's own talkgroup on the SSC TRS. Stennis Space Center is located right off of I-10 in Hancock County, and also runs along I-59 just inside of the MS state line.

 

[nexus]

ok, your talking about a particular kind of skip, its still skip. i really dont care what kind it is, i just think its neat that i can hear something 200miles away. i would like to know if my area could be heard from a great distance. i posted this to possibly let someone know im hearing their ems 250 miles away, not to be corrected with a science lesson. k?

I wasn't trying to correct you, I was just trying to get involved with the thread with something I thought would help explain what you were experiencing. So that maybe you'd be better prepared and understood when and how it happens.

If you come into this forum then be prepared for science lessons. :wink:

 

[bassmkenk2508]

ah i see. well that makes sense. i tend to overlook the more simple explanations lol. now i think about it i have the same reception quality with stennis s.c. as i did with my "unknown" frequency found. thanks for the assistance, Nexus

 

[nexus]

no problem, at least someone intelligent on here appreciates my input.

 

[INDY72]

Oh this admin appreciates your input very much, since your a valuable sopurce of info for the Gulf Coast area.... especially now that I live in Memphis.

 

[kc5niy]

Hello from North MS. I have just joined the site and actually the traffic you heard was from the Chickasaw County 911 repeater system. Chickasaw Co sisters Monroe County (Aberdeen) and the emergystat private ambulance service was the one being dispatched. The frequency for the Chickasaw Co 911 is 151.070 RX ; 153.890 TX with 167.9 TONE. I have not been very active in the HAM service for the past year or so but when the conditions are right (thermal ducting) we can hear amaetur repeaters 200-300 miles away and sometimes get into the repeater for a short time. By the way Prairie is in Monroe County but they have a good working relationship with Chickasaw.

 

[twolf816]

awesome, i hear it throughout the day, every day. base scanner, mobile scanner, AND portable scanner. (when my local ems isnt TXing) very clear and its always the same female dispatcher 24/7 which is odd.