CTCSS Decoding
 

I would like to try an decode CTCSS tones with my scanner. Most software
that is out there to do this, you must have a discriminator tap so it will
grab the audio better.

I am using WinTone without a discriminator tap, just straight audio into the
line input soundcard. This seems to work somewhat well, but I was wondering
if there is any other program's out there that would be able to do the same
job but without having to use a discriminator tap.

Also, the same goes for decoding trunking systems etc....especially Motorola
systems. Is there any program's out there that will do this with the
straight audio going into the sound card?


Thank you

On Wed, 1 Dec 2004 21:33:38 -0500, "RadioMan2"
m said in
alt.radio.scanner:

I am using WinTone without a discriminator tap, just straight audio into the
line input soundcard. This seems to work somewhat well, but I was wondering
if there is any other program's out there that would be able to do the same
job but without having to use a discriminator tap.

It's not the program. Most radios have a high-pass filter in the
audio so that you don't hear the CTCSS tone.

Al Klein wrote:
It's not the program. Most radios have a high-pass filter in the
audio so that you don't hear the CTCSS tone.

No, most radios have a three-inch speaker that can't reproduce the
CTCSS tone. If you plug a hi-fi speaker into most radios, you'll hear
the CTCSS just fine.

--
The state religion of the USA is atheism, as established by the courts.

clifto wrote:

Al Klein wrote:
It's not the program. Most radios have a high-pass filter in the
audio so that you don't hear the CTCSS tone.

No, most radios have a three-inch speaker that can't reproduce the
CTCSS tone. If you plug a hi-fi speaker into most radios, you'll hear
the CTCSS just fine.

No, don't think so. The CTCSS tones are 'sub-audible', that is, they are below
the range that humans can hear.

dxAce
Michigan
USA



--
The state religion of the USA is atheism, as established by the courts.

dx'tard wrote:



No, don't think so. The CTCSS tones are 'sub-audible', that is, they are below
the range that humans can hear.

You are wrong. Not to say you are a lying.

This is a list of commonly used PL/CTCSS tones
(all in Hz):

67.0 69.3 71.9 74.4 77.0

79.7 82.5 85.4 88.5 91.5

94.8 97.4 100.0 103.5 107.2

110.9 114.8 118.8 123.0 127.3

131.8 136.5 141.3 146.2 151.4

156.7 162.2 167.9 173.8 179.9

186.2 192.8 203.5 206.5 210.7

218.1 225.7 229.1 233.6 241.8

250.3 254.1

You will see that they are very audible on a decent system. The only
reason they are not audible on systems using this tones -and some others
too- is, that they are using a high pass filter cutting all freqs below
300Hz or so.

Volker Tonn wrote:

dx'tard wrote:


No, don't think so. The CTCSS tones are 'sub-audible', that is, they are below
the range that humans can hear.

You are wrong. Not to say you are a lying.

This is a list of commonly used PL/CTCSS tones
(all in Hz):

67.0 69.3 71.9 74.4 77.0

79.7 82.5 85.4 88.5 91.5

94.8 97.4 100.0 103.5 107.2

110.9 114.8 118.8 123.0 127.3

131.8 136.5 141.3 146.2 151.4

156.7 162.2 167.9 173.8 179.9

186.2 192.8 203.5 206.5 210.7

218.1 225.7 229.1 233.6 241.8

250.3 254.1

You will see that they are very audible on a decent system. The only
reason they are not audible on systems using this tones -and some others
too- is, that they are using a high pass filter cutting all freqs below
300Hz or so.

That is correct. So... plugging the radio into a better speaker will therefore not
help... unless the high pass filter is disabled.

dxAce
Michigan
USA

dx'tard wrote:

That is correct. So... plugging the radio into a better speaker will therefore not
help... unless the high pass filter is disabled.

Most VHF/UHF receivers are not having a highpass filter going so high
(300Hz) but only to about 55 Hz in Europe or 65 Hz in US because of the
mains freqs. It's only the transceivers wich are using these tones
having the freqs up to 300Hz blocked to the AF-stage.
It's simple enough to tap the discriminator output on the RX-section of
nearly any (T)RX.
I have a handheld scanner provinding the CTCSS-tones just out of the
headphone jack. The built-in speaker is too tiny to go below 150Hz.
BTW the higher tones above 150Hz are not used very often.

Volker Tonn wrote:

dx'tard wrote:

That is correct. So... plugging the radio into a better speaker will therefore not
help... unless the high pass filter is disabled.

Most VHF/UHF receivers are not having a highpass filter going so high
(300Hz) but only to about 55 Hz in Europe or 65 Hz in US because of the
mains freqs. It's only the transceivers wich are using these tones
having the freqs up to 300Hz blocked to the AF-stage.
It's simple enough to tap the discriminator output on the RX-section of
nearly any (T)RX.
I have a handheld scanner provinding the CTCSS-tones just out of the
headphone jack. The built-in speaker is too tiny to go below 150Hz.
BTW the higher tones above 150Hz are not used very often.

Thanks Deutsche'tard.

dx'tard schrieb:



Thanks Deutsche'tard.

My pleasure.

hugs and kisses

On Wed, 1 Dec 2004 21:33:38 -0500, "RadioMan2"
m wrote:

I would like to try an decode CTCSS tones with my scanner. Most software
that is out there to do this, you must have a discriminator tap so it will
grab the audio better.

Not that it helps you but in RTFMing the manual on my handheld 2m/70cm
transciever it will decode the CTCSS tone. This has to be done on the
receive frequency though so I'd have to be in range of the
transmitting radio rather than the repeater.

Tony