Rapid DTMF Bursts On 154.600 MURS Ch 5

[KV4BL]

I hope I'm posting on the correct area for this particular issue. While it is likely a nationwide phenomenon, I will go with the South Carolina Forum since this is where I am hearing it.

Can anyone tell me what the bursts of approximately four DTMF tones I hear every few seconds to a minute are on MURS Channel 5, 154.600? Occasionally, it sounds as though I hear a PL tone being transmitted with the signal but cannot ascertain what the tone is by use of the tone scan feature on my radio or by letting the radio sit on each CTCSS tone through two or more transmissions of the DTMF bursts. I have noted the signals seem common in the vicinity of Wal-Marts and other large stores which use that frequency for in-store comms, but this may just be a coincidence as the store talkies and the device creating the DTMF bursts are often of noticeably different signal levels.

This is admittedly a trivial question but on a curiosity level, it is maddening. Any help in identifying the device and/or its purpose would be greatly appreciated.

Thanks,

Ray

 

[buckent]

I hope I'm posting on the correct area for this particular issue. While it is likely a nationwide phenomenon, I will go with the South Carolina Forum since this is where I am hearing it.

Can anyone tell me what the bursts of approximately four DTMF tones I hear every few seconds to a minute are on MURS Channel 5, 154.600? Occasionally, it sounds as though I hear a PL tone being transmitted with the signal but cannot ascertain what the tone is by use of the tone scan feature on my radio or by letting the radio sit on each CTCSS tone through two or more transmissions of the DTMF bursts. I have noted the signals seem common in the vicinity of Wal-Marts and other large stores which use that frequency for in-store comms, but this may just be a coincidence as the store talkies and the device creating the DTMF bursts are often of noticeably different signal levels.

This is admittedly a trivial question but on a curiosity level, it is maddening. Any help in identifying the device and/or its purpose would be greatly appreciated.

Thanks,

Ray

Hi ray,

had not been aware of this untill now... will park a radio on 154.600 with a recorder, and see what i get... i do have a DTMF tone decoder (Universal M-400) here in the shack, and will be looking for whatever it finds... will keep you posted here...

 

[p1879]

I think I read that in Southern California some lawn irrigation systems are controlled by murs.
I realize we have had an abundance of rain recently in our area, so perhaps it is something else, but maybe a possibility on a golf course, etc. Data is permissible, and there are murs intrusion alarms, but I think these use a voice synthesizer.

Interesting catch,
good day!
p1879

 

[KV4BL]

DTMF Bursts on 154.600

Hi buckent and p1879! Thank you both for your replies! Interesting possibility on golf course or lawn irrigation system!

Buckent, that is a great idea you have about recording and decoding the tones! Unfortunately, a DTMF decoder is not in my arsenal of monitoring equipment at this time. Please let me know what you find out.

Again, many thanks to both of you for your replies!

Ray

 

[K4KNJ]

Ray,

Most Likely you are hearing the Alerts for a nearby business. Some Businesses that uses Murs will set up Alert Zones in thier are and every once in a while they will send out a tone...if the tone is heard (OR if you transmit on the correct PL tone) by another radio it will announce " Alert Zone 4 " pending on what Alert Zone you are in...This is done so some businesses can keep employees within their coverage area and not fade into the sunset...There is several in Florence that does this method as well

 

[p1879]

Yes, speaking of "Alert zones" the Dakota Alert Murs Driveway alarm
transmits a voice alert such as "Alert zone 1". Each transmitter can be set to an individual zone number, so zone 1 could be the driveway and zone 2 could be monitoring the trail, etc. out back. (You would probably get alerted to lots of deer in many places!)They also make different models connected to a pressure hose, for vehicles, so wildlife will not false the alarm. These alarm are supposed to work over a goodly distance, and are helpful for long driveways or for remote building protection.
p1879