Sorry, this deserves a better expansion. Sometimes I get in a hurry. Asterisk ships audio around (on the links, etc) as line-level audio (not pre-emphasized and needs no de-epmhasis). This works out great for telephones, computer clients, voice announcements, etc because Asterisk doesn't have to do any filtering. After all Asterisk is a telephone PBX where you would expect audio to be line-level (speaker/mic) audio. This leaves the pre/de-emphasis up to app_rpt channel drivers. Chan_usbradio and chan_voter can add pre-emphasis. Chan_simpleusb cannot pre-emphasise. With chan_voter the DSP pre-emphasis is turned on by setting txctcss = xxx.x in voter.conf. If you want pre-emphasis but no TX P/L set txctcss = to some (any) tone and set txctcsslevel = 0. Hope that helps. -- Tim :wq On Aug 28, 2013, at 10:26 AM, Tim Sawyer <tim.sawyer@me.com> wrote:

Absolutely, yes. That is it's normal mode. -- Tim :wq

On Aug 28, 2013, at 9:42 AM, KJ6KO <kj6ko@innercite.com> wrote:

...

I am looking into an RTCM. Does it have the capability of driving a modulator directly? May have to use it with an old Palomar controller which is set up for direct modulator input style TX audio (pre-emphasized)

txprelim=yes?

I know it has the ability to de-emphasize the DISC audio from the Palomar.

Thanks..

__________ Information from ESET NOD32 Antivirus, version of virus signature database 8738 (20130828) __________

That's right, there is no txprelem setting for RTCM's. Pre-emphasis is done by setting txctcss which causes chan_voter to turn on DSP pre-emphasis and setting txctcsslevel=0 forces no tone. So yeah, it's sort of a fake out. Chan_usbradio txprelim will generate pre-emphasis when using a DMK URI or any other USB audio FOB. The preemp is none in chan_usbradio not in the USB FOB. That's true, chan_voter and voter.conf is the interface to RTCM's even if not voting. -- Tim :wq On Aug 28, 2013, at 4:21 PM, KJ6KO <kj6ko@innercite.com> wrote:

AH! Besides answering another question I had about the "audio standard" on Asterisk being "line level" spkr/mic audio, you are sying the txprelim=yes is not what does it in a RTCM? Does that still need to be set?

Sounds like you are basically "fooling" it by telling it to generate a PL, which makes it think it is connected directly to a modulator, hence it will pre-emphasize the audio automatically? Setting the txctcsslevel=0 just kills the tone.

Do I have it correct now?

ALSO, Since chan_simpleusb will not pre-emph, will a DMK URI do it if you use the chan_usbradio to drive it?

Lets see how many other questions I can cram in here.....

I assume since I do not have an RTCM yet, that the chan_voter is what is used for the RTCM? Even if it is NOT being used as a voter system, just a radio interface?

Thakns for the help Tim!!

I'm learnin'

73 de Greg ----- Original Message ----- From: Tim Sawyer To: KJ6KO Cc: App_rpt-users@ohnosec.org Sent: Wednesday, August 28, 2013 12:46 PM Subject: Re: [App_rpt-users] RTCM txprelim?

Sorry, this deserves a better expansion. Sometimes I get in a hurry.

Asterisk ships audio around (on the links, etc) as line-level audio (not pre-emphasized and needs no de-epmhasis). This works out great for telephones, computer clients, voice announcements, etc because Asterisk doesn't have to do any filtering. After all Asterisk is a telephone PBX where you would expect audio to be line-level (speaker/mic) audio. This leaves the pre/de-emphasis up to app_rpt channel drivers. Chan_usbradio and chan_voter can add pre-emphasis. Chan_simpleusb cannot pre-emphasise.

With chan_voter the DSP pre-emphasis is turned on by setting txctcss = xxx.x in voter.conf. If you want pre-emphasis but no TX P/L set txctcss = to some (any) tone and set txctcsslevel = 0.

Hope that helps. -- Tim :wq

On Aug 28, 2013, at 10:26 AM, Tim Sawyer <tim.sawyer@me.com> wrote:

...

Absolutely, yes. That is it's normal mode. -- Tim :wq

On Aug 28, 2013, at 9:42 AM, KJ6KO <kj6ko@innercite.com> wrote:

...

I am looking into an RTCM. Does it have the capability of driving a modulator directly? May have to use it with an old Palomar controller which is set up for direct modulator input style TX audio (pre-emphasized)

txprelim=yes?

I know it has the ability to de-emphasize the DISC audio from the Palomar.

Thanks..

__________ Information from ESET NOD32 Antivirus, version of virus signature database 8738 (20130828) __________

__________ Information from ESET NOD32 Antivirus, version of virus signature database 8739 (20130828) __________

The message was checked by ESET NOD32 Antivirus.

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