LoJack Hit?
- Thread starter Dispatrick
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Wiki
This is from Wiki....interesting read....
"LoJack transmits on a radio (RF) carrier frequency of 173.075 MHz. Vehicles with the system installed send a 200 millisecond (ms) chirp every ten seconds on this frequency. When being tracked after reported stolen, the devices send out a 200 ms signal once per second.[4][5] The radio frequency transmitted by LoJack is near the VHF spectrum band formerly used in North America by analog television channel 7,[6] although there was minimal interference due to the low power of radiation, brief chirp duration, and long interval between chirps.[7] The Lojack signal is received in equipped police vehicles utilizing a phased array antenna system, hence the four distinctive antennas on the roof. This provides the direction finding capabilities of the LoJack system."
This is from Wiki....interesting read....
"LoJack transmits on a radio (RF) carrier frequency of 173.075 MHz. Vehicles with the system installed send a 200 millisecond (ms) chirp every ten seconds on this frequency. When being tracked after reported stolen, the devices send out a 200 ms signal once per second.[4][5] The radio frequency transmitted by LoJack is near the VHF spectrum band formerly used in North America by analog television channel 7,[6] although there was minimal interference due to the low power of radiation, brief chirp duration, and long interval between chirps.[7] The Lojack signal is received in equipped police vehicles utilizing a phased array antenna system, hence the four distinctive antennas on the roof. This provides the direction finding capabilities of the LoJack system."
nd5y
Member
Yes, but LoJack is not a nationwide service. It only operates in certain areas, mainly around large metro areas, they don't have base stations everywhere, not every police dept has tracking receivers, and 173.075 may be used by the federal government outside of LoJack market areas.
gguy396XT
Member
According to the FCC database, there are seven towers covering the lojack frequency for North Carolina, with frequency licensed to the SBI.
http://wireless2.fcc.gov/UlsApp/UlsSearch/licenseLocSum.jsp?licKey=2874163
http://wireless2.fcc.gov/UlsApp/UlsSearch/licenseLocSum.jsp?licKey=****953
I must be picking up the towers in Garner, NC and Durham, NC.
*EDIT: wow, RR must not like the numbers '666' because it keeps changing them to '***' in my url.
For the second link, change the licKey number to two six six six nine five three. geez.
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ecps92
Member
Not True in every Region as to Large Metro Areas.
Additionally the 3 letter Agency vacated 0750 for the exclusive use of Vehicle Tracking
And since this is an international forum, Frequencies do vary by Country
Additionally the 3 letter Agency vacated 0750 for the exclusive use of Vehicle Tracking
And since this is an international forum, Frequencies do vary by Country
nd5y
Member
If the FBI vacated it then some other agency still uses it.
47CFR90.20(e)(6) The frequency 173.075 MHz is available for stolen vehicle recovery systems on a shared basis with Federal stations in the fixed and mobile services.
47CFR90.20(e)(6) The frequency 173.075 MHz is available for stolen vehicle recovery systems on a shared basis with Federal stations in the fixed and mobile services.
ecps92
Member
troshs
Member
http://www.google.com/url?sa=t&sour...8ICYAQ&usg=AFQjCNE778vtUKxev-gpFlrXygikoEKu8Q
The above link is a PDF of the Lo Jack user manual. Page 16 discusses coverage areas. Way out of my range.
Sent from my SAMSUNG-SGH-I337 using Tapatalk
The above link is a PDF of the Lo Jack user manual. Page 16 discusses coverage areas. Way out of my range.
Sent from my SAMSUNG-SGH-I337 using Tapatalk
AC2OY
Member
Wow good stuff here kids. Sadly I admit I never saw a weather cube and used to frequent Radio Shack a lot. My wife's car came with LoJack in the deal. I think every once in a blue moon I get hit on 173.xxx it dies say Federal it just buzzes loudly maybe that's LoJack!!!
scottyhetzel
Member
The police units use three roof antennas for the past 5 years.
ecps92
Member
Still 4 here in New England, sometimes they get lost in the Car Wash :roll:
I've seen other systems use the 3 Antennas, tho - Definately Not Lo/Jack
I've seen other systems use the 3 Antennas, tho - Definately Not Lo/Jack
KB7MIB
Member
Wirelessly posted (Opera/9.80 (BREW; Opera Mini/6.0.3/27.2354; U; en) Presto/2.8.119 320X240 LG VN530)
IIRC, 3 antennas is for the bank bag trackers in the 216-220 MHz range, and 4 antennas is for LoJack tracking.
This may have changed, or I may be misremembering it.
IIRC, 3 antennas is for the bank bag trackers in the 216-220 MHz range, and 4 antennas is for LoJack tracking.
This may have changed, or I may be misremembering it.
902
Member
The bag tracking thing have diversified into laptops, construction equipment, and basically into anything that can fit their small circuit board and activation mechanism. People steal all kinds of crap, not just money. The three antennas pretty much perform about as well as the four, and register a front/side direction on a display that's similar to a Doppler DF unit. To paraphrase Raul Julia from Gumball Rally, what's-a behind me, she's-a no matter. There are also fixed solutions on 220 MHz that can alert when something goes into a particular area, then the control point can send cars with Doppler DF devices into the expected footprint. The company offering that service is not LoJack and the frequencies/hardware are different (but otherwise pretty similar - if that makes sense).
My personal preference in DF is a hybrid between active DF and the device pushing GPS coordinates (like APRS). I've had two cars stolen (once right out of my driveway) since I've been where I live now. They were recovered, but were essentially stripped of anything personal inside. To limit my future losses, I now have several different ways of finding them, have onboard recording and diagnostics like a "bait car," and I can see them moving around the screen like a James Bond movie. I don't necessarily like living that way, but those are modern problems.
My personal preference in DF is a hybrid between active DF and the device pushing GPS coordinates (like APRS). I've had two cars stolen (once right out of my driveway) since I've been where I live now. They were recovered, but were essentially stripped of anything personal inside. To limit my future losses, I now have several different ways of finding them, have onboard recording and diagnostics like a "bait car," and I can see them moving around the screen like a James Bond movie. I don't necessarily like living that way, but those are modern problems.
scottyhetzel
Member
I am a LoJack installer and I can tell you the old versions use 4 antenna arrays and late model arrays are three. Also we use the cars fm antenna for output of LoJack.
stlouisx50
Member
Thanks to the installer, for the new info 
Do you have to have your squelch all the way open to hear the chirps being that they are ms. chirps?
Do you have to have your squelch all the way open to hear the chirps being that they are ms. chirps?All i get is ham radio chatter on those frequencies
We have a secondary allocation from 219-220, so we share it with other services.
Oh ok that explains. Awesome.
nd5y
Member
The secondary amateur allocation on 219-220 MHz is for point-to-point digital links only. The regular amateur band is 222-225. If you were hearing hams in the 219-220 band it was probably images or mixing from another frequency or possibly bootleggers.
Can't hear Lojack
I have 173.0750 programmed into my 996XT but still cannot pick up any lo-jack signals from the vehicles. The police were chasing a car that went north past my house, then the chase went east about 3 blocks from my house and finally south about 1/2 block from my house and I did not pick up the signal at all. I have an Antenna craft ST4 about 30 feet in the air. I can hear the towers transmitting a data burst every minute or so but that is all I hear. I hear the police talking about the bars they getting and the direction the signal is coming from but no lojack. I live in the LA area so we do have an abundance of stolen cars on a daily basis.
Is there something I'm missing? A setting in the radio perhaps?
Thanks.
I have 173.0750 programmed into my 996XT but still cannot pick up any lo-jack signals from the vehicles. The police were chasing a car that went north past my house, then the chase went east about 3 blocks from my house and finally south about 1/2 block from my house and I did not pick up the signal at all. I have an Antenna craft ST4 about 30 feet in the air. I can hear the towers transmitting a data burst every minute or so but that is all I hear. I hear the police talking about the bars they getting and the direction the signal is coming from but no lojack. I live in the LA area so we do have an abundance of stolen cars on a daily basis.
Is there something I'm missing? A setting in the radio perhaps?
Thanks.
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