Analog vs Digital

[DMGins]

Am about to buy my first scanner and have been told local fire and police departments are switching from analog to digital. Does anyone know if railroads are planning to do the same. Would sure hate to lay out $$$$ for an analog scanner only to find I can't listen to railroad talk. Have queried several sources on this to no avail. Many thanx.

dmgins

[kr4bd]

It is my understanding that most radio services will have to convert to a narrower bandwidth at some future date. I have heard that the year 2012 has been designated for some services like Public Safety communications. To do this, many agencies are going to digital, which is very narrow banded. Most current analog transmissions do not meet these new FCC mandated, narrow band standards. I am sure the railroads will have to adjust, too, at some point. The reason for all this is to conserve radio spectrum. The cell phone industry, in particular, is gobbling up spectrum like there is no tomorrow. TV transmissions are supposed to go ALL digital by the end of 2006, but many doubt that will happen by then. Also, the TV spectrum above Channel 60 is being withdrawn and redistributed to mobile radio, cell phones, etc. This means there will soon be NO TV stations above Channel 60.

I think digital scanners will be getting cheaper in the near future and all of them do receive analog signals. So, I would probably get a digital scanner to cover more future options.

The thing to worry about, in my opinion, is encrypted digital which many police agencies (and others) are going to. There are NO scanners that will receive such transmissions (and probably never will) due to new laws that prohibit reception of encrypted signals by unauthorized parties.

Another thing about digital which can get pretty "deep" is the fact that there are many different formats of digital transmission and no scanner will currently work on all of them. Many agencies are adopting what is known as APCO-25 standards for digital transmissions so different services can easily communicate with one another. As more and more agencies are going digital, they are finding all sorts of incompatibilty problems for inter-agency communications. If they all adopt APCO-25 standards, they have a better chance of being able to communicate with each other.

This may seem a bit complicated as far as railroads are currently concerned. I have noticed, however, that CSX and NS have all applied for trunked radio systems which are being experimented with in some areas... So, this means you better get a trunking scanner, too. And, again, there are several trunking systems out there (Motorola, EDACS, LTR, etc.). Most scanners will usually only work with one or two trunking systems.

Ahhh.... for the good old days.... when we just plugged in crystals....

Tom, KR4BD
Lexington, KY

[videobruce]

I can't imagine Marine & Railroad allocations being in the VHF high band, just to name two, being forced to go digital unless Motorola is really hurting to sell more radios!

[clearblock]

Due to the need for nationwide compatibility with radios in run-through power, I think any RR conversion to digital in the immediate future would be limited to specific, local applications. For example, some RR police may go digital if they get P25 digital radios to communicate with local public safety agencies.

It is doubtful you will see any change in train dispatch voice communications until there has been an industry wide conversion to digital equipment. When this day comes, it is possible that computer based train control system will have replaced wayside signals and most voice communications.

The FCC has postponed digital/narrow band mandatory conversion dates before and I would not be surprised to see the 2012 date 'slip" also.

It makes no sense to buy a digital scanner now unless it is to monitor an existing publc safety system that has gone digital. With the various digital formats and encryption that may be implemented in the future there is no assurance a digital scanner you buy today will work with some unknown system you may want to monitor in the future.

[kr4bd]

I agree that most RR communications will probaby NOT go digital anytime soon and I also agree that the FCC may delay any mandatory moves to digital transmissions. However, in many parts of the country, the "old RR frequencies" in the 160-161 mHz range are now being allocated to services outside the RR industry if no interference is caused to railroads. This is also happening on the former Marine frequencies around 156-157 mHz in areas far from navigable waters. Some, not all, of these new users into these formerly protected RR and Marine frequencies ARE using digital transmissions.

I also agree that buying ANY scanner today is risky, because you never know what changes may be coming that will affect what you like to listen to. I still have an old 1971 vintage Regency scanner which used Crystals for frequency determination. It still works, but what I can listen to anymore is surely becoming limited as many services go digital, or move to trunked systems or migragted up to UHF frequencies. Scanning certainly is a rapidly changing world if you listen to other things in addition to Railroads.

[Ken W2KB]

The AAR is active in the current 900Mhz FCC notice of proposed rulemaking to restructure this band. It is my understanding that the railroads have an interest in moving to a 900MHz digital, probably scrambled for critical infrastructure protection purposes. Being driven by need for improved efficiency, expanded uses and homeland security issues. It will be a couple of years, at a minimum, before this transition can be made.

[clearblock]

The AAR is active in the current 900Mhz FCC notice of proposed rulemaking to restructure this band. It is my understanding that the railroads have an interest in moving to a 900MHz digital....

The AAR's primary interest in 900 MHz is for the Advanced Train Control System / Positive Train Control data network. It is described in this FCC notice:

http://www.fcc.gov/Bureaus/Wireless/Ord ... 010359.txt

This is a signaling and data system and is not specifically a "transition" of existing voice systems. If implemented, it will probably replace some voice traffic with data messages to display terminals in the locomotives.