SQ Mode, Code Questions

[BOBRR]

Hello,

Sure is a lot to know. Using a HP-1 with Butel.

For "Conventional" frequency System lists, I have generated some FAV lists from information I have copied from RR and elsewhere.

Many of the frequencies have CTCSS showing under SQ Mode in parts of the FAV list, but for many frequencies in the list they are just blank.
Same for the SQ Code.

My main objective/concern is that I don't want to miss anything due to a wrong, or missing, code.

I am thinking that perhaps the best thing for me would be to avoid all of them, and worry about any interference only if it actually occurs.

But am not really sure that this would be best.

Would you suggest just setting everything to: Search, None, or ALL ? Which/Why ?
Could you perhaps explain what each of these setting does, please ?

Is "None" the exact same as just leaving it blank ?

Would "Search" be better ?

What does "All" actually do.

What do you think would be best approach for me ?

Again, I am willing, I think, to put up with occasional interference between transmitters, but
would like not to miss anything due to an improper, or missing, Code.

Thanks,
Bob

 

[jonwienke]

Don't sweat it. A CTCSS tone or DCS code is used to allow a receiver to ignore any incoming transmissions that do not have it. It's generally used on repeaters to prevent the repeater from being triggered by random interference. If you leave it blank, the scanner will play all traffic on the channel, regardless of whether it has a tone or code.

 

[ofd8001]

I concur with the above post and putting a finer point on the pencil:

Where the database is blank, it could be for two reasons. One is that no one has submitted tone squelch information. The other is that the particular channel may not use tone squelch.

Is "None" the exact same as just leaving it blank ?

"None" may be better than blank, but see below.

Would "Search" be better ?

Yes. It is possible a tone squelch may be in use, but hasn't made it to the database. Search means the scanner will "search" the transmission for a tone squelch and advise you, so it can be programmed. Then you could make the submission to the database for it to be updated.

Typically when a tone squelch is not listed in the database, I will set it to search, presuming it is a conventional frequency.

There is a "however" to this. My scanner is on an outside antenna. A fire department 40 miles south of me uses 154..4300 for dispatching. A fire department 20 miles north uses the same channel, also for dispatching. The "south" department does not use tone squelch, but the "north" does. So if I search and find a tone squelch 110.9, I might erroneously report that as being the "south's" tone squelch. Even worse, I could program my scanner for that tone squelch and no longer receive the "south" department.

What does "All" actually do.

There are three different types of tone squelch. CTCSS is a tone squelch. A sub-audio tone embedded in the transmission. DCS is digital coded squelch. There is a data stream in the transmission in place of the tone squelch. It is the "next generation" of CTCSS. The above are used in analog frequencies.

The last is P25 which is for digital conventional frequencies. These will be NAC or Network Access Code, and it is another type of digital data embedded in the transmission.

All three of these serve to eliminate interference from "foreign" radio stations. The radio spectrum is limited and frequencies are re-used (note the above example).

So to answer your question: "All" tells your scanner to listen for "all" three of these. If you choose CTCSS or DCS, the programming software and scanner would ignore any of the P25/NAC "stuff" it might hear. Also if you choose CTCSS, DCS or P25, the software and scanner would expect an entry in the next column, either search or a numerical value.

 

[BOBRR]

Hi Folks,

Thanks for great info.
Appreciate it.

Sure is a lot to learn/know.

Regards,
Bob