Tone in use by CSX

[INDY72]

CSXT is putting an 250.3 CTCSS tone out on its chans here in Indy. Seems to be only the Dispatch Console? Not sure when it began, but all my scanners are showing this on the IC, IB Dispatch, and the Ex Conrail, Ex Chessie Road freqs. Anyone have info on this? Also, does the IB dispatcher now do both IB and IC Chans sometimes, or is this a permanent change starting now?

 

[alabamarailfan]

This has been brought up before. I hear it on multiple CSX dispatcher channels here in Alabama. I discovered by accident as I thought there was a weird hum I hadn't heard before and it turned out to be the 250.3 Hz tone. On my live feeds, I put a 250 Hz audio notch filter to cut it out.

My understanding was that it was only used on dispatcher channels and that maybe only the dispatcher and MOW crews used it but I can't remember the purpose right now. It was not used by trains. If I can find the post/thread about it, I will post it back here.

 

[AK9R]

The IB and IC dispatcher desks were combined several months ago. Note that all of the dispatcher desks in Indianapolis were moved to Jacksonville, also several months ago.

 

[Nasby]

I always thought that this was just my scanner reverting to a random tone every now and then when in CTCSS Search mode.

When I programmed the tone, the squelch would not open.

I can't think of any good reason that a mainline dispatcher channel would have a receive tone with it.
Perhaps a transmit tone because the radio programmer left it on when setting up the radio (which won't affect anything) but certainly not a receive tone.

 

[INDY72]

I think I got it figured out. The tone is to pop the linemen, signal maintainers, other MOW radios specifically. I think they added this after a few incidents where trains vs people that had NO advance warning of each other etc. Now if Dispatcher keys up that toned, it will automatically open those folks radios, and vice versa.

 

[EricCottrell]

Hello,

From what I understand it is not a tone to open up radios, but an anti-tone to mute radios. The base stations on the NEC here in MA transmit a PL tone. A person who works Comms for the line said the purpose of PL is to prevent feedback at the dispatcher's console due to other base stations picking up the transmission. The locomotive radios on the NEC do not transmit PL.

73 Eric

 

[INDY72]

Hello,

From what I understand it is not a tone to open up radios, but an anti-tone to mute radios. The base stations on the NEC here in MA transmit a PL tone. A person who works Comms for the line said the purpose of PL is to prevent feedback at the dispatcher's console due to other base stations picking up the transmission. The locomotive radios on the NEC do not transmit PL.

73 Eric

That makes a kind of sense.

 

[ecps92]

We have seen, here in New England, some of the RR Consoles use CTCSS [outside of some Repeater or Non Console Ops] it was explained that this is a muting feature for the other consoles to prevent feed back

Hope this helps.

edit - that will teach me to always read the entire thread... Eric already posted similar.

CSXT is putting an 250.3 CTCSS tone out on its chans here in Indy. Seems to be only the Dispatch Console? Not sure when it began, but all my scanners are showing this on the IC, IB Dispatch, and the Ex Conrail, Ex Chessie Road freqs. Anyone have info on this? Also, does the IB dispatcher now do both IB and IC Chans sometimes, or is this a permanent change starting now?