CSX Anderson Base (160.8 mHz) using low frequency tone - 250.3. i don't believe its for Sq control. I think its for base select from Jacksonville. Anyone near the other bases who can check to see if & what tone they may be using. Works fine when set as CT.
CSX Anderson Base
- Thread starter dfoutch
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It's an answer back tone that's on each dispatcher base that alerts whomever "tones up" or calls the dispatcher that the dispatcher has been alerted that someone is calling on that base. The dispatcher does not hear the tone. On their end all unanswered bases flash on their console until they acknowledge the call(s).
OK, very interesting, Thanks 91
Actually the CSX answer back tone is a "brrrrrrrrrrrrp" noise which sort of, but not really, resembles a phone ring.
I think what the OP is talking about is the PL tone that all of the CSX wayside base stations transmit when the DS is talking (250.3 Hz, Moto code M7). I've noticed it around here as well.
That being said, I've never been able to figure out exactly what they're doing with that. Back in the Conrail days, all CR defect detectors transmitted a PL tone (I think it was 100.0), which if I recall correctly passed the audio through the receiver at the nearest wayside base so the defect detector transmissions would be recorded at the dispatch center. The DS didn't hear it when the wayside base was not selected on his/her console.
The only thing I can think of is that CSX is doing something similar; I have no idea what it is exactly, but there's probably a receiver somewhere (even if it's just sitting on the local train master's desk) which only passes audio when the DS is talking.
Ok I hear the "brrrrrrrrrrrrp" noise as well. Theirs also a short higher tone sound when a radio keys up, I think that,s the call up tone. I don't remember hearing the low frequency tone before ID moving to Jacksonville. You hearing it in Ohio means it is prob not base select. However theirs only so many tones.
A short "bleep" noise when the base station keys up would probably be the tone remote PTT command (probably 2175 Hz) telling the base station to transmit. The CSX dispatcher probably wouldn't be using that (although they could be) as I believe most all of their wayside base stations are now connected to Jacksonville through the Verizon satellite network along with the signal system. It could be a yardmaster radio or something like that, as the radio is located near the yard but not necessarily at the building the yardmaster is in; the tone commands and TX/RX audio are sent over a wireline connection between the base station and the desktop control unit.
To contact the dispatcher, the train crew presses a key on the radio keypad which sends a DTMF tone to call the DS. The length of that can vary depending on how long the eager radio user in the cab leans on the button. After you hear that you would then hear the "brrrrrrrrrrrrp" noise to indicate the call was received and placed in queue, waiting for the DS to respond.
ecps92
Member
Just as WAG , based on some New England Railroads
Some regional Dispatch centers use the PL to mute the other consoles, to prevent Feedback to the console
and the Engines are CSQ only dispatch has a PL
Some regional Dispatch centers use the PL to mute the other consoles, to prevent Feedback to the console
and the Engines are CSQ only dispatch has a PL
I can confirm that the CSX IC dispatcher channel (AAR 030, 160.560 MHz) bases in the Indianapolis area transmit a 250.3 Hz CTCSS tone while the dispatcher is keyed up.
Thanks W9BU. I've got one other thought, South Anderson has three other fixed base frequencies, #31-160.680, #50-160.860(Yard-Avon & Hawthorn remote) and #45-160.785(Yard) along with #46-160.800. Could the 250.3 tone be used to separate adjacent ch interference to the network receivers. 9BU if the IC Tx is at Avon could it be same problem their.
I wonder if this is a new thing for CSX dispatchers. Several years ago before CSX closed the Huntington, WV dispatcher's office there were two dispatching territories in Ohio on the same frequency (161.520 mHz) about 90 miles apart at the closest that when skip would be active would step on each other all the time and the dispatchers would notice and complain.
Trains use dtmf to key up the alert tone for dispatch. If you listen close you hear beep boop...brippppp.then CSX IB dispatcher, Jacksonville etc. Dispatch can select any base station they want depending which sounds best for them. The tone is as mentioned is for TX inhibit.
So sooner or later all cab & handheld radios will also need to Tx this tone to inhibit other radios. Most do not at this time. I think its a good deal.
I'm assuming that the purpose is to give the dispatcher priority so that others don't key up on top of him. The cab and handheld radios should be configured with Busy Tone Lock Out to keep them from keying up when the dispatcher is talking and they should not be configured to transmit the tone. That's my guess.
I was thinking more of radios keying on one another as when more then one crew is in the yard. Line crews do their on "Set offs" in SA yard on the line frequency. Local crews use the yard frequency.
I think its for safety. Keep it simple. Same for repeaters. Don't depend on it to work in an emergency. Computers, now that's different.
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