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Date: 10/29/22 06:45
Locomotive radio antennas
Author: twropr

I used to see lots of engines equipped with firecracker antennas - do they still make them? Which are most common today - coat hangers or whips? Which type of loco antenna has the best reception?
Andy

Posted from Android



Date: 10/29/22 07:26
Re: Locomotive radio antennas
Author: Notch7

Mostly they use the upside down skate type like the Sinclair.  I heard the change was for PTC/GPS reasons.



Date: 10/29/22 10:35
Re: Locomotive radio antennas
Author: K3HX

twropr Wrote:
-------------------------------------------------------
> I used to see lots of engines equipped with
> firecracker antennas - do they still make them?
> Which are most common today - coat hangers or
> whips? Which type of loco antenna has the best
> reception?
> Andy
>
> Posted from Android

"Firecracker" antennas (dielectric loaded antennas)
are much more expensive than the usual "skate"
antenna and are targets for thieves as many are almost
entirely copper.

As for performance, a whip antenna will likely perform
better but are not used as they are not as ruggedly
constructed as the "skate" antennas which often are
equipped with a tough plastic cover.

Be Well,

Tim Colbert  K3HX



Date: 10/30/22 12:24
Re: Locomotive radio antennas
Author: WW

Locomotive antennas are relatively efficient because the roof of the cab acts a very good ground plane.  The plastic cover used commonly today for antennas may cover more than just the VHF voice communications antenna.  PTC operates outside of the VHF band, in part so it does not interfere with the VHF voice band and vice versa, so those antennas may be also located under the plastic dome, along with the UHF train telemetry antennas.

Also, in most flatland areas, mobile railroad radios (including locomotive radios) do not have reach long distances.  Most remote bases are not much more that 20 miles apart, some with even less spacing.  In hilly or mountainous areas, railroads will often use wide area mountaintop repeaters where even portable radios could reach repeaters dozens of miles away.  My often-quoted example was the U.P. mountaintop repeater located on Cheyenne Mountain west of Colorado Springs, Colorado.  Mobile radios could reach it from as far away just a couple of miles south of Cheyenne, Wyoming, about 170 air miles away.  BNSF also had a repeater somewhere in that area that could reach similar distances.  I could hear it on a mobile radio for up to 100 miles in any direction from its location.



Edited 1 time(s). Last edit at 10/30/22 12:25 by WW.



Date: 11/15/22 08:59
Re: Locomotive radio antennas
Author: engineerinvirginia

The gadget is called an antenna farm and it has elements for radio, EOT/HTD, PTC, and GPS...and my experience is if it gets whacked hard enough NOTHING will work in the cab. Except maybe PTC which probably has much redundancy somewhere on the locomotive. 



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