Beeps and Rings

I am looking for a CD or other media recording of a railroad telegraph suitable to put in a restored depot as a background sound. Anything that can steer to a possible source would be appreciated. I have done a Google source to no avail.

spence.smith wrote:I am looking for a CD or other media recording of a railroad telegraph suitable to put in a restored depot as a background sound. Anything that can steer to a possible source would be appreciated. I have done a Google source to no avail.

The best search phrase is "american morse code" recordings. Found this one http://www.morsetelegraphclub.org/libra ... rought.mp3

Plate F wrote:That was a city police transmission captured on a railroad frequency with the interference tone. So what happened was that the police signal was too strong and pried into the railroad frequency? But why is it only on THAT particular frequency I ever hear the noise or even the wrong broadcast for that fact?

A radio "listens" to frequencies both above and below the local oscillator frequency, the local oscillator runs at either plus or minus the radios IF... That is what an image is, [some people call 'em 'intermods, which means intermodulation products' (or just mixing products)also at various multiples of the local oscillator frequency. These are real signals.. Real radios have preselection to filter these signals out, scanners, being broadbanded, escentially do not. These signals are another reason why an external preamplifier can cause more trouble than it is worth. These signals are real and can cause all kinds of problems, the reason why one is better off with an amateur two meter radio or RR freq only radio over a wide band scanner..... Elsie Kay

EdM wrote:

Plate F wrote:That was a city police transmission captured on a railroad frequency with the interference tone. So what happened was that the police signal was too strong and pried into the railroad frequency? But why is it only on THAT particular frequency I ever hear the noise or even the wrong broadcast for that fact?

A radio "listens" to frequencies both above and below the local oscillator frequency, the local oscillator runs at either plus or minus the radios IF... That is what an image is, [some people call 'em 'intermods, which means intermodulation products' (or just mixing products)also at various multiples of the local oscillator frequency. These are real signals.. Real radios have preselection to filter these signals out, scanners, being broadbanded, escentially do not. These signals are another reason why an external preamplifier can cause more trouble than it is worth. These signals are real and can cause all kinds of problems, the reason why one is better off with an amateur two meter radio or RR freq only radio over a wide band scanner..... Elsie Kay

Nice explanation, thank you.

You guys were right about how the CP system works. The other strange part about the system is that the tones are set up by switching the transmit channels to what they call the “call in channel.” Once the tone is heard, then the dispatcher is spoken to on the main channel. I don’t know why they can’t be set up on the main frequency. They also have special tones to open up waysides to be used as field repeaters.

On CPR, the beep tells that the tower received the key in. The ring means that the tower has successfully sent the call to the dispatcher/RTC radio console, in the office.

I can't say this applies to all operations but generally the Beep indicates the dispatcher is listening to that tower and channel and the Ring indicates the dispatcher is not listening but a waiting call message for the particular tower and channel shows on the dispatcher's console.

This is sometimes defined in operating rules or instructions to immediately state your train or unit ID if you hear the Beep since the dispatcher is listening or wait for the dispatcher to respond if you hear the Ring. In actual practice it seems common to just keep dialing the key-up code regardless of the Beep or Ring until the dispatcher answers by voice.

System that use 911 emergency key-up generally put the channel up on the speakers or headsets at not only the dispatcher's console but also the Chief and sometimes adjacent desks so somebody is sure to hear it and respond.

The reason some systems use a separate call-in channel is so the call-in is more likely to get through than competing with all the chatter on the main channel.