Modulation and CTCSS/DCS questions

[dmg1969]

I was going to post this in the Uniden section, but think it is more of a general question. My BC125AT is the first scanner I have ever owned which allows you to change things like tones and modulation. That being said, I have two questions.

The first one is the difference between setting the tones to OFF or NONE on a given frequency. I think I figured that out. If set to OFF, it will break squelch whether or not it detects a tone. When set to NONE, it will only break squelch if it detects NO tone. Correct? I already know that setting a tone tells the radio to break squelch only if it detects the tone you have programmed.

Now, the next question is about modulation. I am not into amateur radio, so I do not have the electronics/radio knowledge that someone with that background would have. That being said, my question is whether it is best to have the channels in my BC125AT to AUTO for the modulation. If not, how do you determine what the modulation should be based on the frequency.

 

[captclint]

The first one is the difference between setting the tones to OFF or NONE on a given frequency. I think I figured that out. If set to OFF, it will break squelch whether or not it detects a tone. When set to NONE, it will only break squelch if it detects NO tone. Correct? I already know that setting a tone tells the radio to break squelch only if it detects the tone you have programmed.

Not exactly.None will allow everyone through(tone or no tone), and so will SEARCH. I want to be clear that we are not talking about tone lockout being on or off. Having NONE is not the same as programing a tone and selecting tone lockout ON or OFF. Selecting ON will allow everything EXCEPT the tone programmed, and off will only allow that tone through, as you said.

Now, the next question is about modulation. I am not into amateur radio, so I do not have the electronics/radio knowledge that someone with that background would have. That being said, my question is whether it is best to have the channels in my BC125AT to AUTO for the modulation. If not, how do you determine what the modulation should be based on the frequency.

Auto is the safe bet. If a VHF/UHF frequency appears to be too soft, changing to FMN might help since nearly everyone is on narrow band by now, but there is also audio volume boost that could be used. Also, be sure you have the latest firmware, which added narrowband steps.

 

[dmg1969]

Looking back through the BC125AT manual, among the choices for tone are:

Off - the scanner ignores all tones and opens squelch on any signal...tone or no tone.
None - channel squelch will only open if NO tone is detected.

My home county's low band police, fire and EMS frequencies are CSQ (no tone). So, I have all of the frequencies in my scanner set to either OFF or have the tone programmed. Knowing that, I could set my home county's fire 2 channel (46.06) as NONE. I would do that because a neighboring county uses 46.06 as their fire 1 dispatch and they use the 97.4 tone. So, my fire 2 would only open with a CSQ transmission (no tone).

As far as the modulation, I will leave it at auto.

Thanks!

 

[captclint]

Off - the scanner ignores all tones and opens squelch on any signal...tone or no tone.
None - channel squelch will only open if NO tone is detected.

AFAIK, None is a new wrinkle with Uniden, but one which is badly needed.

 

[UPMan]

And that's why I added it.

 

[awattam]

And that's why I added it.

For that we thank you. Also thank you for creating my great scanner (Uniden BCD396XT)

 

[dmg1969]

Hopefully this does not break the rules, but I posted something in my home state's (PA) forum because I am not sure if the problem I am having is unique to the system or not. if it does, please feel free to delete this post and leave the one in the PA forum.

I was hoping to get UPMan's opinion to see if I am missing something.

http://forums.radioreference.com/pe...fire-low-band-patch-open-sky.html#post1945031