Amateur Radio Operation On Amtrak

[CapitolLTD]

I just bought my ticket and asked about amateur radio portable ops on the train as a courtesy to the crew. Spoke with a supervisor because the agent had no clue what I was talking about...she thought I meant a boom box.

The supervisor told me absolutely no amateur radio ops can be done on the train because the crew radios will be interfered with. Anyone heard this before? I would think since I am operating with a PL tone, and way above their freqs, I would not be able to cause a problem.

 

[Eris]

Well, your operations shouldn't interfere at all (and if they did, you'd probably be obligated to cease operations), but PL tone isn't why, since the PL tone is just an additional sub-audible tone that's transmitted on your signal which is used to filter *other* signals by a receiver which *wants* to hear yours- a scanner set to your frequency would hear your transmission just fine.

I can't think of why amateur operations wouldn't be allowed while on board, but this seems like a circumstance where asking permission is just asking to be denied- it's a lot less risky for an agent to tell you "no" than to tell you "yes" (and be wrong). If you must ask permission, ask the conductor once on board.

http://www.wpp-clbc.ca/ham-radio-hf.php has a brief description of an attempt to operate HF on the Empire Builder.

 

[Guest_Yerry_*]

From my Motorola Communications days. . .

It is quite common for a VHF transmitter to "numb" nearby receivers, even those out-of-band. the result won't be static, or distorted audio (such as off-frequency transmission, harmonics, or spurious emissions from a faulty transmitter); the receiver simply goes silent-- numb-- with the squelch locked onto what it thinks is a signal, and the speaker on but silent.

A very large portion of ham radio use in the United States takes place on the 2m band; 147 & 148 MHz. This is very close to the standard railroad frequencies.

Safety issues self-evident.

 

[CapitolLTD]

Good idea to ask the conductor. I will do that with the condition that if there are any problems, I will cease operation.

 

[AmtrakWPK]

Most of the rail freqs are in the 159-160MHz range. They do use commercial radios with pretty good specs, but if you were within a few feet of the conductor you probably would desensitize his radio at least a little. He'd still hear a transmission from the engineer, probably, but not necessarily from dispatch. So 2m operation would be iffy from an interference standpoint. If you have a duo-bander 2m/440, the 440 might be a better bet, although even that might possibly interfere with a passing freight's train-end device, which is a device that is on the tail-end car of freights to send end-of-train data to the engineer at the front end of the train. Those units are in the 460MHz range, I think.

 

[had8ley]

I just bought my ticket and asked about amateur radio portable ops on the train as a courtesy to the crew. Spoke with a supervisor because the agent had no clue what I was talking about...she thought I meant a boom box.
The supervisor told me absolutely no amateur radio ops can be done on the train because the crew radios will be interfered with. Anyone heard this before? I would think since I am operating with a PL tone, and way above their freqs, I would not be able to cause a problem.

Sometimes fear of what "might" happen opens mouth of those who don't know better. (No not a Chines proverb; just good Cajun common sense.)

 

[sechs]

Like airplanes and cell phones, while the probability of a major issue is small, they aren't sure. So, to be safe rather than sorry, the answer is no.

 

[Green Maned Lion]

Reinforced by the revenue they get from "airphones".

 

[Guest_Yerry_*]

I actually DO know better, with a FCC Commercial First Class License to prove it. Got it when I was 17, and while in college, added the microwave and radar endorsements, and held them all until the late 90's (I teach Elementary Science now). Also nearly killed our Mayor when I was 12 when I demonstrated my spark-gap morse-code transmitter to him while he was standing in the wet grass. Mom didn't vote for him anyway, so I wasn't in TOO much trouble.

There seems to be a lot of "Conductor said no, and since I don't like it, he's wrong." I'm really NOT 'shooting at the hip" here. I can numb a Motorola handheld at 50 feet with only 5 watts. Many pranks involving te McDonalds drive-through radio system. This is also why many times crews think their handheld isn't working when they're close to the loco antenna, move away, and suddenly discover it works again. Once when I was told "find a project or get laid off", I took a Motorola HT, solder-sucked off all the tin/lead solder, and resoldered the 1000+ solder joints with beryllium/silver solder; it took two weeks and I got 15% more power and much less susceptibility to numbing. I also had a Buick FM radio in my Chrysler (!) that would go numb from CA highway patrol transmitters; kind of a primitive radar-detector, except for the time it went numb because I was about to get pulled over. . . .

The web citation earlier makes no mention of this, or any problem with the crew: It was actually about using HF (above AM Broadcast and far below Low-band VHF) and how it didn't work because of the steel car created a Faraday Cage which blocked radio waves in both directions. Basically a simplified tech report that had nothing to do with this question. In fact, even though not mentioned specifically, the crew HAD to be amazingly tolerant because of the size and shape of the antennas the author had to use.

I really doubt there's much of any effect on EOT's. Some are on 2m, some are on 1/2m, and NS has one oddball frequency, but all have a hysteresis (to compensate for short-term loss of signal) built-in so the train doesn't shut down every few minutes. Most EOT's are one-way anyway (transmit), and a loco receiver is contained in a very solid cast/milled aluminum case-- pretty good shielding.

And, of course, there's the whole concept of "this stupid radio. . . ". Some specific radios (serial number, not model number) just stink. Maybe there's a missing shield inside, of a solder bulge keeps something from grounding properly, or there's a nearly-bad component inside. if you're issued this radio, and can't get it exchanged/fixed, you get picky about your surroundings. My favorite was a UHF radio that would only transmit if you thumped the top cover the same time you keyed up. Many hours working on that one with no success. . .

 

[Guest_Yerry_*]

And, Amtrak gets no money from "airphones".

 

[Green Maned Lion]

I was only refering to planes. Obviously.

 

[sechs]

Most of which don't have "airphones" anymore, because it's such a money loser.

 

[Green Maned Lion]

I haven't flown since '01.

 

[jackal]

Most EOT's are one-way anyway (transmit), and a loco receiver is contained in a very solid cast/milled aluminum case-- pretty good shielding.

Actually, as a former Alaska Railroad brakeman, I can attest that most EOTs are actually two-way devices and will dump the air pressure in the brake line upon command from the engineer (in modern locomotives, it's automatically done when the engineer puts the main brake handle in emergency; on older locomotives, it's a toggle switch on the HOT device). It's a safety device so that if there's a brake line blockage (or an angle **** cut out) in the middle of the train, the entire train still plugs and all of the brakes go into emergency. (Even without any blockages, it speeds up the process of applying all the brakes, since it takes time for the loss of air pressure to make its way through the train--it's faster if you have the air pressure loss coming from both ends.)

Don't know how interference from other radios would affect this, however. I'm sure at least the newer control units have some sort of verification that the air was dumped, and if the first command didn't do it, it would probably retry.

I know some older FREDs were one-way transmit-only devices, but I don't know how many of those are still in use, as (I believe) it's FRA regs to have a two-way device--at least the ARR's ABTH manual required the FRED be tested during certain terminal brake tests to ensure it would dump the air upon command. I would assume that therefore one-way FREDs (that transmit the brake pressure and accelerometer status--if the train's end is moving or stopped) are not legal anymore, but I could be wrong about that. In any case, I never came across any one-way ones.