NewSDScanner
Member
I'm going to ask some rather technical questions about radio signal but hey, this is a technical forum and a technical hobby, so I expect for this to fit right in! 
Also, while I am going to talk about my area specifically (San Diego) to give examples, these aren't necessarily area-based questions and the answers probably apply to many different areas.
I have a Radio Shack PRO-106/GRE PSR-500 outfitted with an 800MHz antenna. When in north county, scanning the San Diego RCS system, I receive all signals loud and clear pretty much everywhere. Obviously, there are areas where the signal gets iffy, but for the most part, my scanner receives all north county police and fire as if I'm in a police car or fire truck and that is with no external antenna in my house or car, just the 800MHz rubber duck. Nearly all of the north county talkgroups that I listen to are digital and the few that aren't have slightly worse signal than the digitals. The frequency range for the RCS is 856-865MHz.
I also have the San Diego (City) Police Department's dispatch channels programmed into my scanner now. Like the RCS, the system is also a Motorola Type II SmartZone with frequencies ranging from 856-865MHz. However, the City police talkgroups are all still analog.
For some reason, I have a much harder time getting a clear signal when trying to listen to San Diego City Police than RCS, no matter where I am. In certain areas of North County, I receive no SDPD signal but in other areas (most high areas/hills) I receive some traffic clearly. If I drive all the way down to San Diego City itself, I still get marginal reception and in fact I get better reception on some hills in north county than I do in the city itself... What causes this? Is this because the system is mainly analog? Do I just need to mount an external antenna for San Diego City? Why is it that my handheld scanner/rubber duck antenna can pick up RCS so much easier than city even though they are on the same system type and frequencies?
As I said before, San Diego is just one example but I'd just like to learn more about the variables controlling radio waves in general as well as the differences between analog/digital signals and frequencies. Thanks!
Also, while I am going to talk about my area specifically (San Diego) to give examples, these aren't necessarily area-based questions and the answers probably apply to many different areas.I have a Radio Shack PRO-106/GRE PSR-500 outfitted with an 800MHz antenna. When in north county, scanning the San Diego RCS system, I receive all signals loud and clear pretty much everywhere. Obviously, there are areas where the signal gets iffy, but for the most part, my scanner receives all north county police and fire as if I'm in a police car or fire truck and that is with no external antenna in my house or car, just the 800MHz rubber duck. Nearly all of the north county talkgroups that I listen to are digital and the few that aren't have slightly worse signal than the digitals. The frequency range for the RCS is 856-865MHz.
I also have the San Diego (City) Police Department's dispatch channels programmed into my scanner now. Like the RCS, the system is also a Motorola Type II SmartZone with frequencies ranging from 856-865MHz. However, the City police talkgroups are all still analog.
For some reason, I have a much harder time getting a clear signal when trying to listen to San Diego City Police than RCS, no matter where I am. In certain areas of North County, I receive no SDPD signal but in other areas (most high areas/hills) I receive some traffic clearly. If I drive all the way down to San Diego City itself, I still get marginal reception and in fact I get better reception on some hills in north county than I do in the city itself... What causes this? Is this because the system is mainly analog? Do I just need to mount an external antenna for San Diego City? Why is it that my handheld scanner/rubber duck antenna can pick up RCS so much easier than city even though they are on the same system type and frequencies?
As I said before, San Diego is just one example but I'd just like to learn more about the variables controlling radio waves in general as well as the differences between analog/digital signals and frequencies. Thanks!
