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BCD436HP: How to know what DCS turn off code to use?

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#1
I want to scan a system i have done in conventional analog. I want to set a DCS code so i can scan the system with the squelch wide open but only still hear the transmissions and no white noise.

I have gotten something called “DCS Turn off” in the log a few times, but i wonder how i actually apply that to my programming of my scanner. I cant find what the standard DCS turn off code would be, if there even is a such thing ?. Or have i understood the turn off tone concept all wrong?.

The only thing i have found is “DCS 134.4 Hz” IS THE “turnoff code”, but the HZ references to CTCSS and DCS. I guess i have to some how find a DCS in the format like: 031



The log i have gotten:

Selcal 82635
Selcal 22651
Selcal B
Selcal 800
Selcal 7
Selcal 91
Selcal B
Selcal E792
Selcal 518
Selcal 8
Selcal B
Selcal B
Selcal 8
Selcal 6
Selcal F
Selcal D
Selcal 56
Selcal 67 [2018-02-26 19:21:10]
Selcal B [2018-02-26 19:21:10]
Selcal 5 [2018-02-26 19:21:11]
DCS - turn off [2018-02-26 19:32:19]
Selcal 82618 [2018-02-26 19:32:19]
DCS 325 [2018-02-26 19:32:27]
DCS 432 [2018-02-26 19:32:29]
Selcal 70091 [2018-02-26 19:32:32]
Selcal B [2018-02-26 19:21:12]
Selcal E [2018-02-26 19:21:12]
Selcal 3 [2018-02-26 19:21:13]
DCS 346 [2018-02-26 19:21:14]
Selcal B [2018-02-26 19:21:17]
DCS 606 [2018-02-26 19:21:18]
DCS 565 [2018-02-26 19:21:21]
DCS 624 [2018-02-26 19:21:26]
Selcal B [2018-02-26 19:21:28]
Selcal 0 [2018-02-26 19:21:29]
Selcal 79 [2018-02-26 19:21:32]
Selcal D [2018-02-26 19:21:33]
Selcal E [2018-02-26 19:21:33]
DCS - turn off [2018-02-26 19:21:36]
DCS 246 [2018-02-26 19:21:37]
Selcal 70091 [2018-02-26 19:21:38]
Selcal B [2018-02-26 19:48:13]
DCS 155 [2018-02-26 19:48:13]
Selcal 22686 [2018-02-26 19:48:15]
DCS 325 [2018-02-26 19:48:38]
Selcal 70091 [2018-02-26 19:48:40]
Selcal DB [2018-02-26 20:54:03]
DCS - turn off [2018-02-26 20:54:13]
Selcal 70091 [2018-02-26 20:54:19]
DCS 132 [2018-02-26 20:54:24]
DCS 145 [2018-02-26 20:54:28]
DCS 212 [2018-02-26 20:54:47]
DCS 073 [2018-02-26 20:55:00]
DCS 043 [2018-02-26 20:55:07]
DCS 134 [2018-02-26 20:55:29]
DCS 606 [2018-02-26 20:55:36]
Selcal 00 [2018-02-26 20:55:39]
Selcal 700 [2018-02-26 20:55:40]
DCS 145 [2018-02-26 20:57:35]
Selcal 82651 [2018-02-26 23:06:00]
DCS 043 [2018-02-26 23:06:01]
DCS 043 [2018-02-26 23:06:05]
DCS 145 [2018-02-26 23:06:13]
DCS 565 [2018-02-26 23:06:26]
CTCSS 151.4 Hz [2018-02-26 23:06:42]
DCS 252 [2018-02-26 23:06:45]
DCS 043 [2018-02-26 23:06:47]
CTCSS 151.4 Hz [2018-02-26 23:07:13]
Selcal 0000 [2018-02-26 23:07:25]
CTCSS 151.4 Hz [2018-02-26 23:07:45]
DCS 043 [2018-02-26 23:07:47]
DCS 043 [2018-02-26 23:07:49]
Selcal E [2018-02-26 23:07:55]
Selcal 513B80000 [2018-02-26 23:08:13]
DCS 043 [2018-02-26 23:08:18]
DCS 043 [2018-02-26 23:08:25]
CTCSS 151.4 Hz [2018-02-26 23:08:30]
CTCSS 151.4 Hz [2018-02-26 23:08:30]
DCS 156 [2018-02-26 23:08:35]
DCS 043 [2018-02-26 23:08:39]
DCS 246 [2018-02-26 23:08:45]
Selcal 600 [2018-02-26 23:08:52]
DCS 043 [2018-02-26 23:08:57]
Selcal E81 [2018-02-26 23:09:19]
DCS 145 [2018-02-26 23:09:33]
DCS - turn off [2018-02-26 23:09:45]
Selcal 80081 [2018-02-26 23:09:45]
CTCSS 151.4 Hz [2018-02-26 23:09:57]
DCS 145 [2018-02-26 23:10:16]
DCS 043 [2018-02-26 23:10:17]
DCS 212 [2018-02-26 23:10:19]
DCS 212 [2018-02-26 23:10:22]
DCS 565 [2018-02-26 23:10:26]
CTCSS 151.4 Hz [2018-02-26 23:10:26]
CTCSS 151.4 Hz [2018-02-26 23:10:36]
DCS 054 [2018-02-26 23:10:38]
DCS 565 [2018-02-26 23:10:39]
CTCSS 151.4 Hz [2018-02-26 23:10:47]
CTCSS 151.4 Hz [2018-02-26 23:10:47]
DCS 565 [2018-02-26 23:10:50]
DCS 043 [2018-02-26 23:11:00]
DCS 043 [2018-02-26 23:11:16]
CTCSS 151.4 Hz [2018-02-26 23:11:18]
DCS 145 [2018-02-26 23:11:33]
CTCSS 151.4 Hz [2018-02-26 23:11:39]
DCS 043 [2018-02-26 23:11:48]
DCS 565 [2018-02-26 23:11:48]
CTCSS 151.4 Hz [2018-02-26 23:11:49]
DCS 565 [2018-02-26 23:11:52]
CTCSS 151.4 Hz [2018-02-26 23:12:01]
CTCSS 151.4 Hz [2018-02-26 23:12:01]
DCS 145 [2018-02-26 23:12:01]
DCS 162 [2018-02-26 23:12:10]
 
Joined
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#2
You can't do that unless every frequency you scan has a CTCSS tone or DCS code. And even then scanning is going to go much more slowly because the scanner is going to waste a lot of time looking for tones and codes on channels that don't even have a carrier.

Use the squelch as intended and the scanner will scan a lot faster.
 
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Location
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#4
For scanning purposes, that's irrelevant.

Uniden scanners scan analog channels at about 80 channels per second. That works out to about 12.5 milliseconds to tune to a frequency and decide if it has a carrier greater than the minimum level specified by the squelch setting.

Detecting an audio tone in a carrier reliably takes much longer. If you use 2 complete cycles as the minimum detection threshold, that's a minimum of 14.8 additional milliseconds after tuning to the RF frequency. A more realistic criteria to avoid false tone detects is 5 cycles, or 37.2 milliseconds for a 134.4Hz tone.

So scanning with squelch at zero and looking for a 134.4Hz tone takes (12.5 + 37.2)ms per channel, vs 12.5ms per channel, or approximately 1/4 the scan rate of just using squelch as designed. There is no benefit to doing that.
 

UPMan

Uniden Representative
Premium Subscriber
Joined
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Messages
13,287
Location
Arlington, TX
#6
DCS is not an on/off setting. If the channel uses DCS, you should use the DCS code the channel is using to ensure that other nearby users on that frequency are not heard.
 

UPMan

Uniden Representative
Premium Subscriber
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Messages
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Location
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#8
I don't know what part you don't understand. Do you know what DCS is? Or, do you not know how to set the DCS on your scanner(s)? Or, do you not know how to find out what DCS is being used?
 
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#9
DCS (Digital Coded Squelch) is a way to identify the source of a transmission when multiple entities are using the same frequency.

For example, company A may set their radios to use DCS code 065 on a frequency, and set their radios to ignore any transmissions not using DCS code 065. If company B uses the same frequency and DCS code 115, then neither company will hear each others' transmissions.

As a scanner user, you can use this to choose which company's traffic you want to hear. If you only want to hear company A, you would program the frequency with DCS 065. If you only want to hear company B, you would program DCS 115. If you want to hear both, you would leave that option blank, or select "Search", depending on your scanner. The actual values will vary, depending on what frequency you are listening to, and what CTCSS tones or DCS codes users on that frequency in your area are using.
 
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