[PRCo] Re: New Email!

[Jerry "MATT" Matsick]

I recently changed emails and would be most grateful if someone will enter my
new email address:    jerry.matsick at comcast.net
 
Thank you very much!
Jerry "Matt" Matsick 
Jacksonville, Florida

--- On Tue, 6/30/09, trams2 at comcast.net <trams2 at comcast.net> wrote:


From: trams2 at comcast.net <trams2 at comcast.net>
Subject: [PRCo] Re: MetroRail Signalling
To: pittsburgh-railways at dementia.org
Date: Tuesday, June 30, 2009, 3:05 PM



The range of the best human hearing is approximately 20 - 20,000 Hz.  The highest frequencies drop off with age. 



Ed 




----- Original Message ----- 
From: "Joshua Dunfield" <joshua.dunfield at gmail.com> 
To: pittsburgh-railways at dementia.org 
Sent: Tuesday, June 30, 2009 12:46:30 PM GMT -05:00 US/Canada Eastern 
Subject: [PRCo] Re: MetroRail Signalling 

2009/6/29 Schneider Fred <fwschneider at comcast.net>: 
> Russ Jackson called me this evening ... I finally had an opportunity 
> to ask him to explain the Washington Metro signal / ATO / ATC system. 
> 
> His answer is simple.   It is fundamentally no different from the old 
> Pennsylvania Railroad signals that I understood except that it uses a 
> signal frequency in the audible range ... if amplified you would be 
> able to hear it ... the frequency is in the 1000s of cycles per 
> second instead of in the 100s of cycles per second. 

I'm out of my depth here, but frequencies in the 100s of Hz are well 
within audible range; a tuning fork produces 440 Hz, and the lowest 
note on a piano is about 25 Hz, IIRC.  So that part of the explanation 
doesn't seem quite right. 

Digressingly, 
-j.