[aprssig] APRS at the railway

[F4FAP Eric]

Hi Misko,

Sometimes I also do aprs in the high speed TGV (180 MPH / 300 km/h). It works when there is nearby aprs digis on big cities, and also with a better antenna than the standard rubber : I use a SRH-36.
As the TGV is leaving urban areas, relaying is weakening to zero.

Main problems must be some metal layers on the window + Faraday effect. Except being able to put a vhf antenna on the train's roof (one for a 200 mph sport car), I'm afraid there is no way for train aprs (except on old wood cars behind a steam engine ?).

73. Eric, F4FAP in Rennes, France.


> Message: 5
> Date: Sun, 18 Jun 2017 17:23:31 +0200 (CEST)
> From: skoric at uns.ac.rs
> To: "TAPR APRS Mailing List" <aprssig at tapr.org>
> Subject: [aprssig] APRS at the railway
> Message-ID:
> 	<16395.85.219.170.163.1497799411.squirrel at portal.uns.ac.rs>
> Content-Type: text/plain;charset=UTF-8
> 
> Hello all,
> 
> Yesterday I traveled by a train from Krakow to Wroclaw in southern-western
> Poland. I had my handie-talkie ADI AF-16 near the compartment's window,
> plugged in to my APRS laptop. Almost 80-90% of the trip that took more
> than 3.5 hrs, I did not hear any APRS activity. Only the last segment,
> some 50 km or so near Wroclaw, some stations appeared on air. The engine
> was running around 120 km/h almost all the time.
> 
> Generally, I wonder about your experience from the trains elsewhere,
> because I am not sure if my handy antenna was insufficient to catch weaker
> signals, or there was pretty inactivity related to APRS mode the majority
> of my trip?
> 
> Regards,
> 
> Misko SP6/YT7MPB (at the moment in Wroclaw)
>