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Question about Trains

J

jras20

My house is about maybe a mile north of the RR tracks, when a train comes through it messes with the UHF channels the VHF channels arnt effected that much, does a Train send out a signal that messes up UHF? My antenna is even pointed the other direction from the train.
<P ID="signature">______________
jras20</P>
 
> My house is about maybe a mile north of the RR tracks, when
> a train comes through it messes with the UHF channels the
> VHF channels arnt effected that much, does a Train send out
> a signal that messes up UHF? My antenna is even pointed the
> other direction from the train.
>
I live about 5 blocks from train tracks. Never noticed any UHF problems before. I'll check next time one comes by and see what happens. May have something to do with them sending a signal to the grade crossings or communications signals. What kind of train/rail is it? Freight or passenger?<P ID="signature">______________

</P>
 
My antenna is pulling in Austin which is about 30 miles from the transmitter as a crow flys, It seems from what I noticed, it is how fast the train is moving is what causes it, it flickers when the train comes by. My antenna is about 30 feet up going towards Austin.

<P ID="signature">______________
jras20</P>
 
> My house is about maybe a mile north of the RR tracks, when
> a train comes through it messes with the UHF channels the
> VHF channels arnt effected that much, does a Train send out
> a signal that messes up UHF? My antenna is even pointed the
> other direction from the train.
>
I live about 2 blocks from some tracks and often see the 'picket fencing ghosts' onour tv with rabbit ears. Its a reflection of the signal bouncing off the train cars..and then re-inforcing and partially cancelling the signal that comes directly from the xmitting tower.
 
> My antenna is pulling in Austin which is about 30 miles from
> the transmitter as a crow flys, It seems from what I
> noticed, it is how fast the train is moving is what causes
> it, it flickers when the train comes by. My antenna is
> about 30 feet up going towards Austin.

I'm about a half a mile from train tracks, and I haven't noticed anything out of the ordinary when trains go by (and I get both freight and passenger trains coming through). Plus, I live about 50 miles from the closest transmitter, so I would think it would be pretty noticeable if anything happened. It could very well be communications for the rail lines causing the problem, but if that's the case, your local rail lines must be using a system different from the lines in my area.

Post 1027 dedicated to WMXJ, Pompano Beach, FL.<P ID="signature">______________
"Once a week, recovering illusionist Roy Horn reportedly visits Montecore, the tiger that mauled him. Though disturbingly, they’re conjugal visits!" -- Horatio Sanz
http://theradioblog.blogspot.com</P>
 
I've noticed the passing airplane making the signal flutter with an antenna but a train has never done that at my place, to the best of my knowledge. There's a freight line about 1/3 of a mile to my east by CT Route 9 in New Britain, CT. Also, Amtrak's Northeast Corridor inland route is another mile east of that.<P ID="signature">______________
#13 Dan Marino...2005 Football Hall Of Fame Inductee :)</P>
 
> > My antenna is pulling in Austin which is about 30 miles
> from
> > the transmitter as a crow flys, It seems from what I
> > noticed, it is how fast the train is moving is what causes
>
> > it, it flickers when the train comes by. My antenna is
> > about 30 feet up going towards Austin.
>
> I'm about a half a mile from train tracks, and I haven't
> noticed anything out of the ordinary when trains go by (and
> I get both freight and passenger trains coming through).
> Plus, I live about 50 miles from the closest transmitter, so
> I would think it would be pretty noticeable if anything
> happened. It could very well be communications for the rail
> lines causing the problem, but if that's the case, your
> local rail lines must be using a system different from the
> lines in my area.
>
> Post 1027 dedicated to WMXJ, Pompano Beach, FL.
>

What may be causing the interference is that alot of the new diesel locomotives that railroads use today have AC motors in them and that might be what is causing the signal to fade a bit. The engineer has nothing to do with sending a signal from the cab to the crossing gates or signals up ahead that is controlled by electrical curcuit blocks on the track and by the dispatcher.
 
> My house is about maybe a mile north of the RR tracks, when
> a train comes through it messes with the UHF channels the
> VHF channels arnt effected that much, does a Train send out
> a signal that messes up UHF? My antenna is even pointed the
> other direction from the train.

Reflections from the train cars. UHF signals bounce off the train, then back at your antenna. It takes time for that to happen, so by the time the bounce signal reaches your antenna, the signal directly from the transmitting tower is "doing something else" and they interfere with each other. Same phenomonon as a "ghost", except that it's dynamic because the big piece of metal the signals bounce off is moving!

(put a set of rabbit ears on the other side of a wall from a refrigerator & you'll see the "non-dynamic" version of this)

The wavelength of a UHF signal is very different from that of VHF -- channel 14 is roughly 70cm (about 2') long while channel 4 is about 4m (12') long. I suppose you could say a train car is a "bigger target" for UHF. (though it's certainly still big by comparison to a 12' channel 4 wavelength!)
 
> I've noticed the passing airplane making the signal flutter
> with an antenna but a train has never done that at my place,
> to the best of my knowledge. There's a freight line about
> 1/3 of a mile to my east by CT Route 9 in New Britain, CT.
> Also, Amtrak's Northeast Corridor inland route is another
> mile east of that.
>

I live in Midtown Memphis, TN, I know all about what airplanes can do to signals! (Gee, FedEx sure has a lot of planes!) The closest trains are about 1/2 mile south of here and I can't tell that they're doing anything.
 
The same problem of multi-path happens in aeronautical radio installations in helicopters.

They have approved antenna locations for the VHF antennas which minimize the effects of rotor speed. There are some combinations which make helicopter pilots sound like they are being vibrated as if they are transmitting while sitting on an industrial strength paint mixer.

Lee
 
> > My house is about maybe a mile north of the RR tracks,
> when
> > a train comes through it messes with the UHF channels the
> > VHF channels arnt effected that much, does a Train send
> out
> > a signal that messes up UHF? My antenna is even pointed
> the
> > other direction from the train.
> >
> I live about 2 blocks from some tracks and often see the
> 'picket fencing ghosts' onour tv with rabbit ears. Its a
> reflection of the signal bouncing off the train cars..and
> then re-inforcing and partially cancelling the signal that
> comes directly from the xmitting tower.
>
another UHF problem is signal loss during a rainstorm. Also the wind blowing can also cause it on an outside antenna. When I was a kid we only had the little round uhf loop and people were always walking into the room and standing in that certain spot that would mess up the TV. My dad was the worst about that. he would sit down but he would stand in that spot and mess up the TV and make you miss something. He'd say "What yall watching? and we'd reply. We'd be glad to tell you if you'd sit down and quit blocking the station"
 
> The same problem of multi-path happens in aeronautical radio
> installations in helicopters.
>
> They have approved antenna locations for the VHF antennas
> which minimize the effects of rotor speed. There are some
> combinations which make helicopter pilots sound like they
> are being vibrated as if they are transmitting while sitting
> on an industrial strength paint mixer.
>
> Lee

Which is, of course, why most people beat on their chest while talking to impersonate a traffic reporter.

Post 1030 dedicated to WBZ Boston.<P ID="signature">______________
"Once a week, recovering illusionist Roy Horn reportedly visits Montecore, the tiger that mauled him. Though disturbingly, they’re conjugal visits!" -- Horatio Sanz
http://theradioblog.blogspot.com</P>
 
I do not do trains, but as for airplanes, I found at a very young age that channels 2-6 are affected worse and UHF least with 7-13 somewhere in the middle, the opposite of the comments I am reading here. The reason for this is twofold. The higher the band, the higher the gain of the station's antennae, the less signal the stations radiate up at the offending craft. Also, the higher the band, the more the gain at the receive antenna, the more directional most receive antennae are in both the vertical and the horizontal directions, the less they are likely to receive from the offending craft.
Blimps - derigibles - are particularly interesting because the hover so slowly.<P ID="signature">______________
Proud 2 B a pioneering satellite radio subs¢riber
Ai4i is always on the trailing edge of technology
_______________</P><P ID="edit"><FONT class="small">Edited by ai4i on 02/01/06 03:53 AM.</FONT></P>
 
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