I was monitoring a water sprinkler???

[altec]

I'm just curious about this but I'm around a private golf course club and they have a frequency in the 461MHz range. For fun I plugged it in to see if I could hear anyone chit chatting. After a few days of monitoring I have not heard anyone on it but once in a while it keys up for a long period of time with no one saying anything. Its like someone left the mic open accidently and it sits there on the same frequency not making a sound. Locked it out after a while. It displays a PL tone of 100.0 PL. I looked it up on fcc and it says the frequency is used to control the water sprinkler systems. If thats true it explains why it stayed on the same frequency for such a long time. Its a private golf course so I couldn't tell if the water sprinklers were on. I always assumed that PL or DPL tones were for portable radios for people to chit chat with.

Also in the past while using the search feature I came across frequencies that displayed a PL tone in the 152 and 169MHz range that sounded like the control channel of a trunked system. It sounded like a motorboat noise but it wasn't constant. It let up and after a few minutes started up again off and on. Most of the frequencies I find that come up as birdies or noise I lock out but these only caught my attention because they display tones. It don't bug me too much but still have to lock these frequencies out due to the noise or birdies they create. Anyone know anything about this or what devices use PL tones to control something like a water sprinkler? Thanks in advance, Altec

 

[shaft]

Your post reminded me of something that was posted here a while back.

http://www.radioreference.com/forums/showthread.php?t=116247

 

[pappy1]

The tone is what activates the water valve not the frequency. It is the same principle with garage door openers, a tone is used to make them secure(?) so mine will not open yours altho they both ae on the same frequency.

 

[bonus1331]

Greatest thread subject title in a year!

 

[raisindot]

I looked it up on fcc and it says the frequency is used to control the water sprinkler systems.

I've heard that monitoring water sprinkler systems works best if you're high on grass, although my friend Scott says it's only for sods who are going to seed and are going to be mowed down any minute. Still, I'm sure you can get a lot of dirt when you listen in, but just make sure you don't shell out your liquid assets for so-called "green" scanning antennas, or you might get hosed.

Suzie

 

[ab2ms]

Greatest thread subject title in a year!

And now possibly worst pun in a year........

 

[wlmr]

Couldn't resist, did the signal sound like this?

Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....
shuh-shuh-shuh-shuh-shuh....
Fftt....Fftt....

 

[trace1]

Couldn't resist, did the signal sound like this?

Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....
shuh-shuh-shuh-shuh-shuh....
Fftt....Fftt....

Is that an encrypted system???

 

[wlmr]

It's an open standard (quiet except for possible "ploik" sound when closed).

It's used by many sprinkling systems, including some really big ones out in cornfields.

Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....Ff tt....
(Main content delivery)

shuh-shuh-shuh-shuh-shuh....
(Inter-Message overhead and timing)

Just be careful not to get too close to any radiating elements, overexposure is usually causes a cold clammy feeling on your skin.

 

[cubn]

It displays a PL tone of 100.0 PL.

I've monitored two local UHF channels that are licensed to golf courses and on both I hear a constant carrier with the same tone you mentioned. I assume they are used to control the course's water sprinklers.

 

[chrismol1]

It's an open standard (quiet except for possible "ploik" sound when closed).

It's used by many sprinkling systems, including some really big ones out in cornfields.

Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....Ff tt....
(Main content delivery)

shuh-shuh-shuh-shuh-shuh....
(Inter-Message overhead and timing)

Just be careful not to get too close to any radiating elements, overexposure is usually causes a cold clammy feeling on your skin.

yes that ploik, I've heard that before right after the fftt, Fftt, Fftt..then ploik, then the shuh-shuh-shuh-shuh....that comes from a closed system, if you listen closely, you can hear the ploik in between, but sometimes if difficult to distinguish, depending on the speed!

 

[kb2vxa]

Careful you don't get your fftts, shuh shus, and ploiks mixed up unless you're singing backup vocals for a Doo Wop band, then it doesn't matter. Da doo run run or doo wah diddy diiddy wadid Bo Diddly do?

 

[altec]

Couldn't resist, did the signal sound like this?

Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....Fftt....
shuh-shuh-shuh-shuh-shuh....
Fftt....Fftt....

Nope didn't hear anything other then muteness. Like I said it was like the mic was open no one saying anything. Now that I know tones are used for water sprinklers systems thats all I wanted to know. Thanks for everyones help on tones and water sprinklers. Didn't know tones could be used on water sprinklers. Its interesting that such simple devices use tones. Are there any articles for this on the internet? I'll try to see if google pulls up anything. I read that post where a golf course was having problems with their sprinkler system. LOL! Thats hilarious. I would think a few golfers got wet, cussing at the manager and threating the golfballs.

 

[SCANdal]

You guys outdid yourselves here. Great stuff...

Are there any articles for this on the internet? I'll try to see if google pulls up anything.

al,

If you're looking for a tutorial on the subject at hand, do a search for "Supervisory Control and Data Acquisition" or SCADA for short. This is the broad catagory of radio system that you are describing falls under (particularly the "supervisory control" part).

I always assumed that PL or DPL tones were for portable radios for people to chit chat with.

Your assumption is incorrect. In addition to portables, base stations, mobiles, repeaters, all manor of transmitting equipment can use PLs or DPLs.

Also in the past while using the search feature I came across frequencies that displayed a PL tone in the 152 and 169MHz range that sounded like the control channel of a trunked system. It sounded like a motorboat noise but it wasn't constant. It let up and after a few minutes started up again off and on. Most of the frequencies I find that come up as birdies or noise I lock out but these only caught my attention because they display tones. It don't bug me too much but still have to lock these frequencies out due to the noise or birdies they create. Anyone know anything about this or what devices use PL tones to control something like a water sprinkler?

152 MHz? Sounds like a paging (beeper) service to me...

SCANdal

 

[UPMan]

The title of this thread reminded me of an article I read several years ago. The author was trying to track down a weak signal morse-code contact. He could pick up the signal off and on, but the copy was so bad, he couldn't make out the dits from the dahs. But he was motivated and curious so ended up spending the better part of a week trying to make contact ... with his refrigerator. Seems that it had a failing brush (or something) in the motor that threw off some odd RF spurs whenever it ran.

 

[altec]

The title of this thread reminded me of an article I read several years ago. The author was trying to track down a weak signal morse-code contact. He could pick up the signal off and on, but the copy was so bad, he couldn't make out the dits from the dahs. But he was motivated and curious so ended up spending the better part of a week trying to make contact ... with his refrigerator. Seems that it had a failing brush (or something) in the motor that threw off some odd RF spurs whenever it ran.

Cool! Maybe scanners can come in handy predicting failing or problems with motor parts one of these days? I've heard a few frequencies on close call I could never figure out where it was coming from. Just assumed it was interference.

 

[kb2vxa]

It must have been an "or something", induction motors don't have brushes.

"The author was trying to track down a weak signal morse-code contact. He could pick up the signal off and on, but the copy was so bad, he couldn't make out the dits from the dahs."

From the novel On The Beach written by Nevil Shute in 1957. The movie starring Gregory Peck was released in 1959 and as the story goes after a nuclear war a garbled Morse code message, the only radio transmissions heard was picked up by a submarine and traced to San Diego. The shore party found somebody's ham rig still operating, the cord of a window shade tangled around the key. As the wind blew the shade operated the key sending random characters, they shut it down and left making no mention of a refrigerator.

Now THAT'Ss cool Altec, but those mystery signals you hear are just what you think they are, interference. There are so many "electronical boxes" kicking around spitting out junk these days you'll go nuts trying to figure it out so relax and say a little prayer. Oh Lord, give me the strength to smash those I can get my hands on and the serenity to endure those which I cannot.

 

[barlage]

I work at a golf course and we use radios all the time for watering. I think our automatic system uses a frequency, but we use portables to punch in codes to manually turn on certain heads. When we punch it in, it takes a couple seconds before a "message delivered" voice comes on followed by some wierd static noise for a couple seconds, and then the head pops up.

 

[VE3RADIO]

wonder if you could set the sprinklers off with a Motorola radio setup with the correct PL tone for that system.

 

[kb0nly]

I know of one golf course near me that uses a similar system. If i you drove by and transmitted on the 70cm ham band with the right PL, frequency doesn't matter, it would set them off. The receivers are probably pretty wideband and sensitive to anything nearby.

They changed their system, it wasn't just hams driving by setting it off, the city got a UHF frequency for the utility department with a PL of 110.9, that just so happens to be the PL to set off the sprinklers near the clubhouse outdoor dining area, oops. A couple soaked meals and they figured out what was happening, just random interference.

They had a system with a different PL for each sprinkler zone, the main transmitter would send a signal with the PL for the zone they wanted to water and it would transmit for the amount of time that the system was watering, no signal no water.