pl tones?

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wtp

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not a railfan but

from what i have read here railroads do not use tones
probably for safety
if someone had a different tone they might not hear someone else
and that could be a matter of life and death
 

ecps92

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Yes, some of the channels do use PL Tones.

Connecticut Railroad - Scan New England Wiki

RI Railroad Communications - Scan New England Wiki

Railroads - Scan New England Wiki

Generally most folks program w/o a PL to hear both sides of the conversation.
We've seen Dispatchers with PL where the Trains were CSQ

There are also (when you get to Repeaters) other uses that do require PL to keep from hitting more than one Repeater

does the amtrack ne corridor use pl tones?
 

timkilbride

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from what i have read here railroads do not use tones
probably for safety
if someone had a different tone they might not hear someone else
and that could be a matter of life and death
When we get foreign power for our own trains, we have a hell of a time getting over foreign property. They require a PL tone, but UP, BNSF, NS, ect. . . don't have that programmed into the radio's. We we either have to use another engine in the consist(if we have one) or having everything keep getting relayed via our dispatcher. Luckily its only a 15 miles trip.

Tim
 

N9NRA

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Correct me if i`m worng here, but isn`t there some rule that railroad radios can`t use PL tones anyway for saftey reasons? as in every radio has to hear/communicate with any other radio on the channel? I recall a conversation i had with a fellow ham up in NW WI about that once and he said that they don`t use PL`s for that reason. Besides, having no PL to worry about just makes it easier for the users, no having to try to remember which PL for which channel/repeater. N9NRA
 

slapshot0017

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The only Railroads I know of that use PL are commuter rails that use the same frequency on multiple lines that are closer to each other. They mainly only work on their property so they don't technically have to worry about "interoperability".

Normally a class 1 freight railroad doesnt use them due to the fact they move all over the place and can be in NY one day and CA the next. That doesn't mean shortlines or volunteers can't have them, but there is really no point for a freight railroad to use them...

Police and special services on the railroads do use PL tones. Police use it for the fact that they use repeaters and need some kind of tone to access the repeater. All of their repeaters have the same frequency because they aren't used as often as municipality. Another reason is that If you are dispatcher in NY using a 100 watt output and only want to talk to a unit in lets say NJ and a dispatcher in CT is doing the same thing to a unit in CT, you don't want to key up their repeater and occupy the frequency.Then it just makes for a bunch of doubling and no one can get their transmissions out...
 

timkilbride

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Correct me if i`m worng here, but isn`t there some rule that railroad radios can`t use PL tones anyway for saftey reasons? as in every radio has to hear/communicate with any other radio on the channel? I recall a conversation i had with a fellow ham up in NW WI about that once and he said that they don`t use PL`s for that reason. Besides, having no PL to worry about just makes it easier for the users, no having to try to remember which PL for which channel/repeater. N9NRA
I'm not aware of any "rule" or law about PL usage in the rail industry. The places where I have been that used PL, was all yard limits. Not 60MPH freight's or passenger.

Tim
 

FrensicPic

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I'm not aware of any "rule" or law about PL usage in the rail industry. The places where I have been that used PL, was all yard limits. Not 60MPH freight's or passenger.

Tim
Same here...in L.A. Amtrak uses DCS for their UHF yard repeater and Amtrak PD uses PL for their VHF repeater. The road frequencies, any railroad, are "open".
 

kruser

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I think it is BNSF or NS that has a yard repeater here that uses a PL tone. The repeater output is on one of the standard VHF rail band channels. I've never tried to find the input frequency though as the yard is pretty far away and most of the users are using portables so I doubt I'd ever hear anything on the input side anyway.
I still usually program all rail freqs with no tone or tone search if the older radios I use for rail scanning even have PL/DPL capabilities. I still monitor most of the UP channels with old Electra Bearcat III crystal models or the slightly newer Electra Bearcat BC220, 250 or 300 models. I always loved the audio from the BC250 and 300's. They also seemed to have decent and sensitive front ends especially for low band VHF but were prone to intermod if used with decent outdoor antennas cut for the rail band. Mostly VHF paging back in those days were the problem causers for me so stub filters worked great for eliminating the intermod. Today I use tuned notch filters on these old single and dual conversion IF models as I can notch the 162.xxx WX channels without killing the nearby rail band range of frequencies. Stubs were too broadband in nature if cut for the WX channels and would often reduce the sensitivity of the rail band to the point I'd lose the RR's I was interested in. Stubs worked great when I lived near a yard and was not interested in the road channels but that was usually not the case.
I also used to hang out with a guy named John Sherman who was the yardmaster that worked the tower at the Frisco Lindenwood yard here in town. He would let us sit in the tower with him all day. Or, you could sit at the base of the tower where the radios were located and hear all the audio you wanted as the radio techs would leave the volume cranked on the radios in the radio building! That was cool as you had the same tall antenna they used so you could hear the trains as they were rolling into town from pretty far out. Of course if you were in the tower, you could also hear it all which was the best as he'd also let us throw some of the yard switches for those that could actually be remotely controlled. Most yard switches required switchmen in the yard back in those days though. I think the only motorized switches were on the lines for trains coming into the yard off the main so he could route them into the correct track. This was back in the days they still used the old semaphore type indicators on the main lines for trains approaching the yard.
He often used binoculars for a better view of the automated switches.
And I think the switchmen's actions caused an indicator lamp to change up in the tower when they would throw a switch as a lot of those were blocked from view from the tower due to tall railcars parked on the tracks in the yard. No computers or computer screens back in those days! It was almost all done visually for the yard ops but they did use the radios a lot.

They would leave the radio building open a lot and the frequencies were listed on each radio along with the channel number but I don't recall ever seeing a PL listed and I doubt DPL was even invented yet back then.

The radio room was left open a lot as it was so hot inside from all the tube powered radios and relay coils so I was told. I recall there being a lot of other equipment in the radio building. Mostly old heavy duty looking relays that may have driven the indicator lights up in the tower. I'd guess those relays also sent signals down the old telegraph wires that followed all the main lines for switching the semaphore indicators. I'm pretty sure some audio from distant radios was still sent over the telegraph looking wires which looked like they had been there since the days they actually used morse code keys!
All that stuff is long gone today including the tower. The old semaphore signal that was on the main on the west end of the yard remained into the 80's or early 90's though but I doubt it was operational. Probably some old signal maintainer left it in place and then got it when he retired.
 

PJH

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Generally speaking (another mostly universal post), PL tones are not used on road channels with the major or most regional railroads. The AAR states that you must have an AAR spec radio for interchange - as a lead locomotive - but that does not mean you cannot use PL tones.

The front panel of the AAR radio does not permit you to select a PL tone, but all the AAR radios I have seen since the original Motorola Clean Cab Spectra does permit the radio to be preprogrammed with "Home channels" that may include PL tones or non-standard offsets/frequencies. You can however, select a singletone for those railroads that did/do still use an audible tone to bring up the dispatcher. In most places, it has been replaced by DTMF for just about everything.

Many of the east coast commuter railroads are a country by themselves and do not need to worry about PL tones as they use preprogrammed channels, if even an AAR radio (they don't interchange, so no need to spend extra $$ on radios that will never be used as a leader pulling a coal train around).

Amtrak that runs on some of these type of lines have pools of engines that are dedicated or at least can be configured for these areas and remain there (different cab signal types, LSL, ATS units, etc) so that is not an issue for those. Same with any freight railroad that needs to operate on those lines.

In some instances, PL tones are left on due to programming issues or for other reasons. I know Conrail at one point had a non-standard PL tone of 150.0 on defect detectors, and I cannot recall the reason why they did that. I will tell you that the Springfield line did/does have a PL tone on the base towers, but the locomotives do not have a PL tone transmitted or decoded in the cabs last I checked.

In the yards, that is a whole nuther matter. Those who work in the yards where repeater equipped have their radios programmed to allow repeater use if so desired. The engines (unless a dedicated unit) will just transmit and receive on the repeater output channel - as the engine radio is typically 45 watts and will be heard all over. Of all the radios I have come across with repeater pairs, the receive channel has always been CSQ.

Railroad police - depends on where they are. Amtrak has a very well installed base of repeaters from Boston down to DC. They (as well as large commuter railroads) are the exception to the rule. Most freight railroad police operate by cellphone and/or on local police channels depending on any MOU's. Texas and California is a typical example of this. Otherwise, its the cellphone for dispatch and normal railroad channels if they need to talk to other railroad employee's. Their railroad radios in the patrol vehicles are programmed up with all 97 AAR channels and can use any channel needed to talk to whoever they want...be it UP/BNSF NS/CSX etc. Many times the local RR cops (which are far and few anyways) have it worked out between themselves internally and with other carrier cops.
 
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PMJ2kx

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Our Class II regional (PNWR) uses PL and DPL in a few locations on their road channels, but well inside their territory. The only foreign power we see is up on the A-line to Port Westward (BNSF), and that road channel does not use PL.
 

burner50

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from what i have read here railroads do not use tones
probably for safety
if someone had a different tone they might not hear someone else
and that could be a matter of life and death
That's not entirely true...


We use PL tones on most of our repeaters around here.
 

timkilbride

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Generally speaking (another mostly universal post), PL tones are not used on road channels with the major or most regional railroads. The AAR states that you must have an AAR spec radio for interchange - as a lead locomotive - but that does not mean you cannot use PL tones.

The front panel of the AAR radio does not permit you to select a PL tone, but all the AAR radios I have seen since the original Motorola Clean Cab Spectra does permit the radio to be preprogrammed with "Home channels" that may include PL tones or non-standard offsets/frequencies. You can however, select a singletone for those railroads that did/do still use an audible tone to bring up the dispatcher. In most places, it has been replaced by DTMF for just about everything.

Many of the east coast commuter railroads are a country by themselves and do not need to worry about PL tones as they use preprogrammed channels, if even an AAR radio (they don't interchange, so no need to spend extra $$ on radios that will never be used as a leader pulling a coal train around).

Amtrak that runs on some of these type of lines have pools of engines that are dedicated or at least can be configured for these areas and remain there (different cab signal types, LSL, ATS units, etc) so that is not an issue for those. Same with any freight railroad that needs to operate on those lines.

In some instances, PL tones are left on due to programming issues or for other reasons. I know Conrail at one point had a non-standard PL tone of 150.0 on defect detectors, and I cannot recall the reason why they did that. I will tell you that the Springfield line did/does have a PL tone on the base towers, but the locomotives do not have a PL tone transmitted or decoded in the cabs last I checked.

In the yards, that is a whole nuther matter. Those who work in the yards where repeater equipped have their radios programmed to allow repeater use if so desired. The engines (unless a dedicated unit) will just transmit and receive on the repeater output channel - as the engine radio is typically 45 watts and will be heard all over. Of all the radios I have come across with repeater pairs, the receive channel has always been CSQ.

Railroad police - depends on where they are. Amtrak has a very well installed base of repeaters from Boston down to DC. They (as well as large commuter railroads) are the exception to the rule. Most freight railroad police operate by cellphone and/or on local police channels depending on any MOU's. Texas and California is a typical example of this. Otherwise, its the cellphone for dispatch and normal railroad channels if they need to talk to other railroad employee's. Their railroad radios in the patrol vehicles are programmed up with all 97 AAR channels and can use any channel needed to talk to whoever they want...be it UP/BNSF NS/CSX etc. Many times the local RR cops (which are far and few anyways) have it worked out between themselves internally and with other carrier cops.
Regarding Conrail PL tone, the cab radio would send out an alert in the cab when it heard that PL tone notifying the crew it had a defect. I wish that was still used to today :)

Tim
 
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