Re: any hints for a long distance train traveller to be?

["Adam Dunning" <adamdunning@start.com.au>]

Wavelength refers to the wave in the direction of propogation (travel) and
the distance over which the wave rises to its maximum (from zero), returns
to zero, drops to it's minimum ( -ve max) and returns again to zero.  It
does not refer to the amplitude (height) of the wave.  It is quite possible
for waves of 13 to 60 metres to fit in a window.

The body of the train and the rails could possibly help in the recieveing of
the waves due to their size.

Adam

"Peter Parker" <parkerp@alphalink.com.au> wrote in message
3add88ff@news.alphalink.com.au">news:3add88ff@news.alphalink.com.au...
>
> Kylie Fan <AussieKylieFan-==-@yahoo.com> wrote in message
> 3add3b9d$0$25475$7f31c96c@news01.syd.optusnet.com.au">news:3add3b9d$0$25475$7f31c96c@news01.syd.optusnet.com.au...
>
> > thats why i am taking a shortwave
> > i have no probs picking up the BBC, radio aus or even on a good night
> duche
> > welle
>
> Inside the carriage?
>
> I doubt it.
>
> Think of a train as an earthed metal enclosure.
>
> You are trying to receive shortwave signals between about 6 and 22 MHz.
The
> wavelengths
> of these is between 13 and 60 metres.
>
> Visualise a radio wave of that size trying to penetrate a train window one
> or two metres square
> or less.  If signals are very strong, you may get some reception inside.
> This may be
> the case in Europe where there are many stations transmitting within a
> single hop
> (1000 to 2000 kilometres away).  In Australia where signals must make
> several
> hops to get from the transmitter overseas to hear, more hops are required
> and
> signals tend to be weaker.
>
> Therefore I don't like your chances of receiving shortwave.  Buses are
> better for
> this purpose.  Trams can have high levels of electrical noise that spoils
> reception.
> In any case you should generally get a window seat on the side of the
train
> facing
> the radio station.
>
> VHF and UHF signals have shorter wavelengths, and so aren't as heavily
> attenuated
> as lower frequencies.  However coating on windows can attenuate UHF
> signals -
> most notably on 1.3 GHz, though also obeservable on 432 MHz.  144 MHz is
> less affected.  I have found FM broadcast radios work well inside trains,
> especially
> if you use a radio with a telescopic whip.  Portable TVs should also be OK
> in some
> places, though I haven't tried this.
>
> Peter
>
>
>
>