Re: Centrol Radio system question

[Steve Dalton <daltongang@smart.net.au>]

Some Drivers have advised me that while sitting at Spencer Street they
can hear me talking to a Driver in Shepparton and Vica Versa whilst
waiting for a line free tone to call me. I would say it is the famous
Railway Gremlins at it again.
Steve Dalton
Notagunzel wrote:
> 
> Another question for any learned correspondents.
> 
> The Victorian Centrol Train to Base radio system operates as a Land Mobile
> system, where the Base transmission is on a separate frequency to the Mobile
> transmit/Base receive.  Each Corridor is allocated a pair of frequencies,
> and when the Base transmits, all the sites on a particular frequency
> transmit simulcast.
> 
> All radio traffic is normally directly between Centrol and the Train, and
> Centrol can 'patch' a Driver through to a 3rd party if necessary, eg. a
> metro Signalbox or the Diesel foreman at Dynon or whatever.  There is never
> radio traffic from Train to Train via the Centrol system.
> 
> Therefore there is no need for the radio traffic from the Train, on the Base
> receive frequency, to be retransmitted on the Base transmit frequency.  When
> it is, it is 'talkthrough' operation, as found on ARTC & ASR, and the ETRB,
> and the Victorian Police for that matter.
> 
> Now for the question: on the Bendigo corridor Ch. 4 (Base tx - 419.050 Mhz &
> rx - 409.600 Mhz) the Uplink (Driver) side can be heard on the Downlink
> (Centrol) side, but on no other channel. Why Is It So????
> 
> P.S. the drivers don't hear it, but it can be heard with a scanner, which
> prompted the question.
> 
> B.