Pro-96 CT Search Question

[kd4bas]

When using my Pro-96 and scanning for active CT tones, I notice that sometimes the squelch will open and the tone of 118.8 will be displayed, but then another CT tone will display when other users key up and talk.

I notice this on all bands and on simplex and repeater systems and was wondering if anyone else has noticed this happening.

If this question has been asked in the past, please forgive me since the search did not show any such query.

 

[Al42]

When using my Pro-96 and scanning for active CT tones, I notice that sometimes the squelch will open and the tone of 118.8 will be displayed, but then another CT tone will display when other users key up and talk.

I notice this on all bands and on simplex and repeater systems and was wondering if anyone else has noticed this happening.

If this question

Question? There was a question there?

Seriously:

Assuming you don't know the reason for CT: if you program a receiver to use that tone, you won't hear all the other systems on the frequency that use different tones.

Why do different users transmit different tones? Because they're on different systems. (Maybe the sheriff's department and the police department use the same frequency, but different tones. Or maybe there's another user on that frequency 50 miles away and sometimes, when conditions are right, the local users can hear those signals if their receivers weren't looking for a different tone.

See http://www.radioreference.com/apps/wiki/index.php?title=CTCSS and http://www.radioreference.com/apps/wiki/index.php?title=DCS.

I hope something here answers your question.

Edit (to fix the major formatting screwup I never noticed )

 

[bravo14]

Hello all,
I know a difference when I heard sheriff's net north florida. I see 4 to 5 different tones codes. I do not have it set because it is a low channel only dispatch is clear. I hate when a different city or county comes in. Sometimes I notice too was when I hearing some channels numbers change when they talk have to be careful when program the number even the 800 trunk system does that too. On the pro96 if a number comes up just hit enter key and the code number is locked in. I have that setup because our tac1 locks up at certain areas and if the tone code is set it will not pick up anything else the older model scanners like 92 and so on if the tone code is set and leave it on manual *not scanning* it will pick up anything that recives. If you town has 2 or more tone codes on the same freq I proably would set up each channel with different tones on it.

 

[Voyager]

When using my Pro-96 and scanning for active CT tones, I notice that sometimes the squelch will open and the tone of 118.8 will be displayed, but then another CT tone will display when other users key up and talk.

I notice this on all bands and on simplex and repeater systems and was wondering if anyone else has noticed this happening.

If this question has been asked in the past, please forgive me since the search did not show any such query.

AC hum will cause a false 118.8. (and sometimes 179.9)

Joe M.

 

[Al42]

AC hum will cause a false 118.8. (and sometimes 179.9)

Both second and third harmonics? Digital tone detection is wonderful.