Ive been searching the FCC ULS and have found a few frequencies that i haven't seen before. some are in the 452mhz range with an ERP of 1 watt. I heard the rumor that GCT has a few frequencies that will never be public, but i am wondering if anyone knows the use of the 452mhz channels?
Metro North Railroad NYC
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Darkstar350
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Most likely low powered portables or vehicle/crossband repeaters and possibly even data
The use of the railroad 452/457 frequencies in the NY metro area at least is definitely few and far between but i actually have confirmed at least one of the 452mhz as a vehicle repeater and portables on the 457 side
Not sure if it was maintenance, or just general railroad ops or what but im pretty sure it was the MTA...
The use of the railroad 452/457 frequencies in the NY metro area at least is definitely few and far between but i actually have confirmed at least one of the 452mhz as a vehicle repeater and portables on the 457 side
Not sure if it was maintenance, or just general railroad ops or what but im pretty sure it was the MTA...
As far as the "secret frequencies" they have at GCT, are they in the regular RR band?
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Darkstar350
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I havent the slightest clue and even if i did know then it wouldnt be a secret if i posted it 
Best thing to do in these cases is to run close call in the area and maybe keep some things to yourself
Best thing to do in these cases is to run close call in the area and maybe keep some things to yourself
That could be end-of-train telemetry. See the bottom of
http://www.radioreference.com/apps/db/?aid=7747
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Those are the frequencies, I wonder if it's encrypted? I've heard of free software you can use to monitor this. I literally live above the IRT in Harlem. Late nights I can feel a distant rumble on my apartment floor. I've also heard that it may be encrypted..
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Darkstar350
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I have also heard that some of the 452mhz railroad freqs can actually be used for somewhat of a wireless PA system within the trains or stations i guess for conductors making announcements to the passengers,etc
If they use encryption then its probobly Nexedge
And if they use digital on simplex from what i understand simplex digital voice cant be decoded very efficiently...
If they use encryption then its probobly Nexedge
And if they use digital on simplex from what i understand simplex digital voice cant be decoded very efficiently...
The communications system in the subway is very intricate.
I've heard of the 6 wire but unsure how you even access it even as a user of it.
Someone once told me about 20 years back that it is like 2 tin cans and a wire. No RF signal
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I've heard of the 6 wire but unsure how you even access it even as a user of it.
Someone once told me about 20 years back that it is like 2 tin cans and a wire. No RF signal
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Darkstar350
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For simplex comms or the actual NYCTA subway ops?
Because i get a pretty good signal on the main subway freqs with a outdoor antenna and im outside of the city...
Because i get a pretty good signal on the main subway freqs with a outdoor antenna and im outside of the city...
radioman2001
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There is nothing nefarious with the 452 channels. LIRR used some for cross-band repeaters years ago, and some are used for remote testing, but that's all I can or will say about them. Plus at 1 watt you would have to be on top of them to hear.
quote"The communications system in the subway is very intricate.
I've heard of the 6 wire but unsure how you even access it even as a user of it.
Someone once told me about 20 years back that it is like 2 tin cans and a wire. No RF signal
Having worked on the subway radio systems years back they had radiating cable(300 ohm twin lead) running everywhere, so you really had to be right on top of it to work. There were instances where I could not talk to another radio point to point which I could see 100 yards away. All of that Twinax (brand name) has been replaced with Andrew Teflon (fire resistance) coated Radiax TM cable. All stations were in the 20 watt range of power level so you have to be right on top of whoever is transmitting to hear them.
Now GCT has about 18 miles of radiating cable running everywhere, since VHF doesn't like tunnels. I actually ran a test with my group a few years ago in a 1 mile tunnel. After about 60-70 yards I could not hear the other radio on VHF, but UHF was loud and clear. I actually could yell to the user and be heard better than the radio.
quote"The communications system in the subway is very intricate.
I've heard of the 6 wire but unsure how you even access it even as a user of it.
Someone once told me about 20 years back that it is like 2 tin cans and a wire. No RF signal
Having worked on the subway radio systems years back they had radiating cable(300 ohm twin lead) running everywhere, so you really had to be right on top of it to work. There were instances where I could not talk to another radio point to point which I could see 100 yards away. All of that Twinax (brand name) has been replaced with Andrew Teflon (fire resistance) coated Radiax TM cable. All stations were in the 20 watt range of power level so you have to be right on top of whoever is transmitting to hear them.
Now GCT has about 18 miles of radiating cable running everywhere, since VHF doesn't like tunnels. I actually ran a test with my group a few years ago in a 1 mile tunnel. After about 60-70 yards I could not hear the other radio on VHF, but UHF was loud and clear. I actually could yell to the user and be heard better than the radio.
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902
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They're not alone. The Port Authority had a 452 MHz railroad channel going back the 80s (yes, they were assigned to the LR frequency pool). It was supposed to be used by the PATH administrative types, but was rarely used, if ever. They had a bunch of Yaesu official non-ham dual-band brick portables going back 20 years. Just about 100% of the actual work was on VHF. There was also a volunteer ambulance squad up in Westchester or Dutchess on the frequency after a while. I don't know what they use it for (if they use it at all) now.
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