Sentinel: Radio Reference database, is it concise?

[TheWitness34]

I downloaded sentinel today in preparation for my SDS100. Is the database a compilation of YEARS of frequency entries? Do you ever have to add your own frequencies to your scanner because they’re not in there? Also, how do you find frequencies if they’re not in the database?

 

[nessnet]

It is as current as WE (everyone) makes it.

Remember, the RR database consists of all us users verifying data and then submitting it.
It is (usually) updated by Uniden (they pull data for Sentinel) every Monday. Oh, in RR, if shaded green, it is data that was updated within 24 hours. Yellow was updated in the past week.
And yes, we certainly add stuff ourselves when something new isn't in the database yet, or we have sniffed something out to monitor/submit.
(Some of us have sniffed out new stuff via the FCC. Then monitor, verify and submit to RR).

As to finding new....
Your question mentions "frequencies", however it is (can be) a bit more complicated than that.
Conventional uses "frequencies", but most of what'll be new nowadays is probably trunking ...(?)

Not knowing your degree of knowledge in regard to trunking makes it hard to answer your question any further.
If you don't know what trunking or a control channel is, I'd strongly suggest you start there, learn the basics (how trunking works), first. Then, we can go into using your new radio and discuss trunkgroups, and ID searching vs ID scanning.

 

[MtnBiker2005]

You would have to add stuff in favorite list yourself, for the stuff that isn’t allowed in the RR database.

 

[n1chu]

To nessnet; I found your post to be most accurate, much appreciated. As to “trunking”, a basic understanding I have always kept in mind was the answer to the question “Why go to a much more complicated and expensive form of communications?” The answer was the FCC was running out of frequencies. There are only so many frequencies available. So the industry came up with a system were they would take numerous frequencies in a new band the FCC made available in the 800 MHz range and, using a computer, they would bunch all of a city’s needs into that one system, the computer would continually assign a specific frequency to any given department. Each department’s radios would be assigned a talkgroup (TG), or numerous TG’s and the computer would keep track of the separation between the comms. Police would not interfere with the FD, and so on. This was in an effort to reduce the need for additional frequencies going forward. It works out ok, but it’s expense usually runs into the multi-million dollar range… whereas the conventional VHF/UHF repeatered systems are cheaper, much cheaper-IF you can find unused frequency pairs. Initially, systems that upgraded to trunking systems were supposed to vacate their old frequencies, freeing them up for other new users but that was changed when the users decided they wanted to keep their old systems as backups (at least until the newer trunked systems proved to be reliable.

 

[nd5y]

how do you find frequencies if they’re not in the database?

Band/limit searching with your scanner is the best way.
The RadioReference Wiki.
Searching the FCC database for licenses and applications.
Searching various federal and other web sites.

 

[nessnet]

To nessnet; I found your post to be most accurate, much appreciated. As to “trunking”, a basic understanding I have always kept in mind was the answer to the question “Why go to a much more complicated and expensive form of communications?” The answer was the FCC was running out of frequencies. There are only so many frequencies available. So the industry came up with a system were they would take numerous frequencies in a new band the FCC made available in the 800 MHz range and, using a computer, they would bunch all of a city’s needs into that one system, the computer would continually assign a specific frequency to any given department. Each department’s radios would be assigned a talkgroup (TG), or numerous TG’s and the computer would keep track of the separation between the comms. Police would not interfere with the FD, and so on. This was in an effort to reduce the need for additional frequencies going forward. It works out ok, but it’s expense usually runs into the multi-million dollar range… whereas the conventional VHF/UHF repeatered systems are cheaper, much cheaper-IF you can find unused frequency pairs. Initially, systems that upgraded to trunking systems were supposed to vacate their old frequencies, freeing them up for other new users but that was changed when the users decided they wanted to keep their old systems as backups (at least until the newer trunked systems proved to be reliable.

Simplified functionally explanation:
The radios 'listen' to a common control channel.
Each radio site ('tower') sends this signal out continuously , and with simulcast, multiple sites are all sending the same control channel out at the same time. Different departments and groups within those departments are assigned trunkgroup IDs.

When someone presses the RX button, the system sends out a digital signal over the control channel (called a channel grant) and both the sender and receiver's (and if a group call, it's other trunk group's member's) radios 'tune' to the frequency the channel grant specifies. They talk (listen) and when done, their radios go back to 'monitoring' to the control channel again for the next transmission meant for them. The important distinction is that fire doesn't hear law or public works (etc.) trunkgroup's transmissions and visa versa.

A bit simplified, but the basics.

Your new SDS100 radio can be set to only listen to what trunkgroups you have programmed in a system (ID scanning), or it can be set (ID searching) to ANY channel grant on the system you have turned it on in.

 

[donc13]

The one thing many "miss" is that, like most, VHF and UHF radio systems, what the "channel" grant tells the radios is "transmit" on freq xyz and "receive" on a second frequency. It's all part of what is know a "repeater" system where low powered handheld radios can be heard by radios that can literally be 100 or more miles away. Scanners "listen" to the receive signal only.

That's a very brief explanation of why you may see someone (say a police of fire dept unit) right across the street from you talking on the radio but you hear nothing on your scanner.

 

[crippledchicken]

I just tried to update my data base and it said I have the latest version was there no update today?

 

[nessnet]

I just tried to update my data base and it said I have the latest version was there no update today?

Yes, it looks like there isn't one today - yet anyway.
On occasion, they (Uniden) misses a Monday - or it is delayed. Not to worry, it will show up eventually....

 

[MtnBiker2005]

RadioReference doesn’t control the update, you would have to contact Uniden about it.

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I just tried to update my data base and it said I have the latest version was there no update today?

 

[MississippiPI]

I have updated my database usually on Mondays after 10am CST. If by chance it didn't then I update the next day.


Be safe

 

[Ensnared]

It depends on where you live. I like to look at the forum associated with the state in particular.

Based on experiences and observations, if there are very few posts or the posts are very old there tends to be a positive, not inverse correlation specific to RR accuracy.

However, I would say there is also say there is a wide variance across the country.

This works for me. I consider it a general rule of thumb.