• EOT devices-how is the signal decoded?

  • Discussion related to railroad radio frequencies, railroad communication practices, equipment, and more.
Discussion related to railroad radio frequencies, railroad communication practices, equipment, and more.

Moderator: Aa3rt

  by Ken W2KB
I suppose someone could jam the signal with a high power transmitter but that would cause at most an inconvenience. Terrorists or vandals have bigger fish to fry.

  by ironken
Clearblock. I was trying to be funny. I have armed the D a few hundred times in my fairly short career.....less than 20 yrs seems to be short around here......C'mon guys, if you can pull the pin and have your 30/60 go golfin, go fishin' but let us young cats have a go at the choice pools......O.K. I'm done whining now.

  by ironken
P.S. Clearblock.....I can't think of any way to disarm the D from the rear end short of smashing it.

  by CN_Hogger
clearblock wrote:
ironken wrote:Thanks for the info. Now I don't have to worry about the Al Quadas shootin the pill on my train. That is unless they thieve a HED.
A stolen HED would not be much of a threat. This is the reason for the arming procedure that requires someone to push the test button on the EOT and then "ARM NOW" on the HTD. The EOT then only responds to commands from the specific HED that armed it.
Unless you've gotten a hold of a self-arming HED... :-)

  by NC167
I have an EOT question. I live about a block away from the CSX line that runs SW out of Philadelphia. Between 15 and 20 trains pass each day. I picked up a scanner and programed in the EOT frequencies but nothing comes over it when a train passes. My scanner only allows me to put in 3 decimal places - 452.937 not 452.9375. Is this the problem because I can return this scanner and get a different one?



  by Aa3rt
Nick-before you return your scanner, try 457.9375.

BTW-by the time you get to that fourth decimal place, you're talking about THOUSANDTHS of MHz-most scanners are not sensitive enough to reject a signal .0005 MHz off frequency.

  by NC167
Thanks Art

That's the other EOT frequency I already have in the scanner.

I can't put in .9375 - the scanner will only accept 3 digits after the decimal so I'm stuck with .937. If that's not the reason why I'm not receiving any signal then I don't know what else to try.

(other than a different scanner)


  by Aa3rt
Nick-how about some basic troubleshooting questions then?

1. Are other frequencies being received on the scanner?

2. Are you listening from a metal or concrete building or is there a metal or concrete building between you and the railroad tracks?

3. If this is a handheld scanner, have you taken it trackside?

4. Have you tried any other signals in this frequency band to ensure that the particular band is working?

Personally, I have a BC60XLT-1 handheld that picks up the EOT devices on the CSX trains that pass through my adopted hometown from about 3/4 of a mile away.

Remember, too, that EOT devices are rather low powered, although your proximity (about a block away) should be more than sufficient for picking up the EOT signal.

  by clearblock
The EOT signal is so brief that you will usually miss it if you are scanning several channels. Have you tried just leaving the scanner set on that specific frequency? The signal is only a "chirp" about 1 second duration.

Is the scanner takes the input of .937 OK, that is fine. Most scanners do not display the 4th digit to the right of the decimal point but .xx7 is actually .xx75 and .xx2 is actually .xx25

The range of the 452.9375 HED is only about 1 mile or so to a handeld scanner and the EOT 457.9375 is less, especially if you are not out in an open area.

  by NC167
Thanks again Art

The scanner does pick up other AAR signals from many other locations.

I just heard a train coming a little while ago and went outside of my house with the scanner. As the train passed the scanner stopped for about 2 seconds on 457.937 but no sound came over it. I put the channel on hold and turned the squelch all the way down and still nothing was coming through. So - at least something is happening!

Are there any other frequencies that CSX uses that can alert me to when a train is coming on this particular line?


  by Aa3rt
Nick, here's a link for railroad frequencies (although the choice of colors makes it a little hard to read) that may help:


As far as the EOT frequency-it sounds like you're on the way to resolving your problem. As clearblock has already mentioned, these are brief databursts sent out at infrequent intervals. You might try locking your scanner on the EOT frequency (and setting the squelch back to normal) to see if you'll possibly hear anything.

You haven't told us what type of scanner you're using. I take it from your previous posts that everything seems to be functioning normally. An amateur radio cohort, who's been licensed longer than I've been alive (and I'm in the over 50 age bracket), always says "Antenna, antenna, antenna". Make sure your antenna is right for the frequency band(s) you wish to listen to, that the connections are secure, and that it is as high as possible in your listening post.

  by clearblock
NC167 wrote:Thanks again Art

Are there any other frequencies that CSX uses that can alert me to when a train is coming on this particular line?

Listen to the ROAD channel for the line you are interested in. If there are any Hot Box or Dragging Equipment Detectors in the area, their transmissions will alert you to train movements. CSX requires the crew to "call" all home signals, announcing the signal location and signal indication so this is usually very helpful.

I am not sure which is correct for the line you are interested in but some CSX frequencies to try for the Philly area are:


  by NC167
Thanks! I finally was able to hear the EOT signal but only while the train was passing. I was able to hear the train itself long before the sound came over the scanner. Even when I put the scanner in a second floor window. The track is only 1/10 of a mile away from my house. I haven't been able to make much sense out of the verbal communications that I've been hearing on other channels. I know I hear Amtrak/30th Street Station and SEPTA communications but nothing that I can say for sure is CSX.

I have the Radio Shack PRO-83 handheld. It only cost $99.00 so I don't know how good it is. I was thinking about getting the 20-006 antenna that they sell also. I read alot of reviews about how well it works. I need to determine if this thing is worth keeping while I'm within the 30 day return period.

All this for my train-crazed 3 year old!


  by clearblock
The PRO-83 should do everything you need for RR monitoring. I do not have any personal experience with that model but all the reviews I have seen have given it good ratings. The more expensive scanners have features like trunking or digital reception which is not presently required for RR monitoring.

I do not recommend the 20-006. It is not going to be a significant improvement over the stock antenna. While there is some theoretical gain, the long telescoping whip is more of a nuisance than it is worth.

The main Amtrak frequency for your area is 160.920.

Check this link for a map of RR lines in your area:


  by NC167
Between the time I posted my message and the time I got a reply I stopped by Radio Shack and.....you're right no difference. All I'm trying to get is a couple minute advance notice before a train is coming. Would an antenna on my roof help? How can I find out if there are "Hot Box or Dragging Equipment Detectors " in my area? And what kind of signal do they send out? I've heard, on 160.050, what sounds like a few seconds of morse code.

I've heard the Amtrak communications on 160.920.