toll transponders

[kc9cra]

I know I wouldn't hear anything useful, but I'm curious what frequency they use. They are required on some roads which to me is screwed up, but I'm sure at one time, folks thought being forced to vaccinate their kids was screwed up. Then, it became so abnormal not to do it, so you now have to whether you trust vaccines or not, whether you believe your child's health is up to God, whatever, you have to.

 

[N4DES]

I'm sure they are all different. On the back of yours there will be an FCC ID #. Plug it into their site site and it will tell you all you need to know about it. Here is the link..
OET -- FCC ID Search

 

[RKG]

Most transponders are not active emitters. Rather, they are swept by a near field generator and will resonate and reflect either a specific return frequency or a specific return bit structure, when is then correlated to their ID number. Same as those building and gate passes some folks have to carry. Since the transponder derives its "power" from the detector RF field, it doesn't require batteries or other external power source.

 

[jhooten]

With the way my 33cm radios act when I go near one of the toll booths I would guess they are in the 900 ISM band.

 

[nd5y]

With the way my 33cm radios act when I go near one of the toll booths I would guess they are in the 900 ISM band.

The ones in the DFW area are.
Texas Scanner Frequencies and Radio Frequency Reference

 

[n9mxq]

Would be interesting to drive under one with a frequency counter going...maybe with an antenna on the roof..

I have noticed rf noise at quite a few tollgates around the country when I drove truck... Both on the CB and my Amateur rigs...

 

[N5TWB]

With the way my 33cm radios act when I go near one of the toll booths I would guess they are in the 900 ISM band.

I occasionally experience a slight chirp out of my UHF ham radio when passing through the toll areas on the Oklahoma Turnpikes.

 

[gewecke]

I'm not sure about others, but in Ill. we use what called the IPASS which might be similar, with this a 915 MHz signal is sent at 500kbps using the IAG protocol in 256-bit packets. Transponders use active Type II read/write technology.
It's kind of neat how they work.

73,
n9zas

 

[n1das]

I know I wouldn't hear anything useful, but I'm curious what frequency they use.

I'm not sure about others, but in Ill. we use what called the IPASS which might be similar, with this a 915 MHz signal is sent at 500kbps using the IAG protocol in 256-bit packets. Transponders use active Type II read/write technology.
It's kind of neat how they work.

73,
n9zas

A while ago I looked up the FCC ID on one of my EZ-Pass transponders. IIRC, the frequency it operates on is 914.7625 MHz.

 

[N4DES]

I occasionally experience a slight chirp out of my UHF ham radio when passing through the toll areas on the Oklahoma Turnpikes.

I get the same in Florida....a quick chirp on 440 if I'm set for CS.