squelch tail

I've been listening on the LA hub and noticed that the systems on there don't have a squelch tail after each receive. I have always had one no mater what radio I've used. My current config is as follows: 1 pair of Icom F221 radios (Full duplex), 1 URI and on Dell PC running ACID (Updated to latest ACID asterisk release.) The COR is hardware from the radio. PL is DSP. What is everyone else doing different?

Thanks & 73
Scott KB2EAR

Scott Weis wrote:

I've been listening on the LA hub and noticed that the systems on there
don't have a squelch tail after each receive. I have always had one no mater
what radio I've used. My current config is as follows: 1 pair of Icom F221
radios (Full duplex), 1 URI and on Dell PC running ACID (Updated to latest
ACID asterisk release.) The COR is hardware from the radio. PL is DSP. What
is everyone else doing different?

Thanks & 73
Scott KB2EAR

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App_rpt-users@qrvc.com
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Hi Scott,

There could be a couple of things that could cause this:

1. COR always asserted from the radio, and carrier detect depending on
CTCSS decode only. Check for signal swing on the COR line with a
voltmeter or a scope and make sure it swings below 0.3V and above 3V for
signal and no signal conditions.

2. There have been reports that when external COR is used with internal
DSP CTCSS decode, that the system doesn't respond as quickly as when DSP
is used for both CTCSS and squelch, or when an external decoder is used
for both CTCSS and the radio's squelch circuit is used. None of this is
confirmed so if you could confirm it, that would be useful.

As a test, try using external COR and CTCSS or a combined signal and see
if that eliminates the squelch tail.

Steve
WA6ZFT

Scott,
For what’s it’s worth, I am running a single Icom F221S UHF radio and using the onboard CTCSS capabilities and it works flawlessly. I don’t have any problems with squelch tails, you may experiment with yours and find that to be the case, let us know how you make out if you do. :slight_smile:

Stephen
K1LNX

···

On Sun, Sep 20, 2009 at 1:55 PM, Scott Weis kb2ear@kb2ear.net wrote:

I’ve been listening on the LA hub and noticed that the systems on there

don’t have a squelch tail after each receive. I have always had one no mater

what radio I’ve used. My current config is as follows: 1 pair of Icom F221

radios (Full duplex), 1 URI and on Dell PC running ACID (Updated to latest

ACID asterisk release.) The COR is hardware from the radio. PL is DSP. What

is everyone else doing different?

Thanks & 73

Scott KB2EAR


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Stephen Brown - ARS K1LNX
Johnson City, TN EM86
http://www.k1lnx.net
google voice: 423-665-9367


stephen,

are you meaning “onboard” to the Icom or the USB fob?

as i too have had problem with certain radios and fobs.

···


Thanks in Advance

Bob Brown, WØNQX

Kansas City Metro Area

http://sm0kenet.net

http://byrg.net

http://kcdstar.byrg.net

“Surely you can’t be serious?” “Of course I am, and don’t call me Shirley.”

Pablo Picasso - “Computers are useless. They can only give you answers.”

On Sun, Sep 20, 2009 at 14:33, Stephen - K1LNX k1lnx@k1lnx.net wrote:

Scott,
For what’s it’s worth, I am running a single Icom F221S UHF radio and using the onboard CTCSS capabilities and it works flawlessly. I don’t have any problems with squelch tails, you may experiment with yours and find that to be the case, let us know how you make out if you do. :slight_smile:

Stephen
K1LNX

On Sun, Sep 20, 2009 at 1:55 PM, Scott Weis kb2ear@kb2ear.net wrote:

I’ve been listening on the LA hub and noticed that the systems on there
don’t have a squelch tail after each receive. I have always had one no mater

what radio I’ve used. My current config is as follows: 1 pair of Icom F221
radios (Full duplex), 1 URI and on Dell PC running ACID (Updated to latest
ACID asterisk release.) The COR is hardware from the radio. PL is DSP. What

is everyone else doing different?

Thanks & 73
Scott KB2EAR


App_rpt-users mailing list
App_rpt-users@qrvc.com

http://qrvc.com/mailman/listinfo/app_rpt-users


Stephen Brown - ARS K1LNX
Johnson City, TN EM86
http://www.k1lnx.net
google voice: 423-665-9367



App_rpt-users mailing list
App_rpt-users@qrvc.com
http://qrvc.com/mailman/listinfo/app_rpt-users

Onboard the radio itself, I set mine to 100hz for both TX and RX for example, and of course disabled the CTCSS option in usbradio.conf

···

On Sun, Sep 20, 2009 at 3:36 PM, Bob Brown - WØNQX bbrown@byrg.net wrote:

stephen,

are you meaning “onboard” to the Icom or the USB fob?

as i too have had problem with certain radios and fobs.


Thanks in Advance

Bob Brown, WØNQX

Kansas City Metro Area

http://sm0kenet.net

http://byrg.net

http://kcdstar.byrg.net

“Surely you can’t be serious?” “Of course I am, and don’t call me Shirley.”

Pablo Picasso - “Computers are useless. They can only give you answers.”

On Sun, Sep 20, 2009 at 14:33, Stephen - K1LNX k1lnx@k1lnx.net wrote:

Scott,
For what’s it’s worth, I am running a single Icom F221S UHF radio and using the onboard CTCSS capabilities and it works flawlessly. I don’t have any problems with squelch tails, you may experiment with yours and find that to be the case, let us know how you make out if you do. :slight_smile:

Stephen
K1LNX

On Sun, Sep 20, 2009 at 1:55 PM, Scott Weis kb2ear@kb2ear.net wrote:

I’ve been listening on the LA hub and noticed that the systems on there
don’t have a squelch tail after each receive. I have always had one no mater

what radio I’ve used. My current config is as follows: 1 pair of Icom F221
radios (Full duplex), 1 URI and on Dell PC running ACID (Updated to latest
ACID asterisk release.) The COR is hardware from the radio. PL is DSP. What

is everyone else doing different?

Thanks & 73
Scott KB2EAR


App_rpt-users mailing list
App_rpt-users@qrvc.com

http://qrvc.com/mailman/listinfo/app_rpt-users


Stephen Brown - ARS K1LNX
Johnson City, TN EM86
http://www.k1lnx.net
google voice: 423-665-9367



App_rpt-users mailing list
App_rpt-users@qrvc.com
http://qrvc.com/mailman/listinfo/app_rpt-users


Stephen Brown - ARS K1LNX
Johnson City, TN EM86
http://www.k1lnx.net
google voice: 423-665-9367


Hi Scott,

There could be a couple of things that could cause this:

1. COR always asserted from the radio, and carrier detect depending on
CTCSS decode only. Check for signal swing on the COR line with a
voltmeter or a scope and make sure it swings below 0.3V and above 3V for
signal and no signal conditions.

COR no signal +12v, COR w/signal 0.0v usbradio.conf = carrierfrom=usbinvert

2. There have been reports that when external COR is used with internal
DSP CTCSS decode, that the system doesn't respond as quickly as when DSP
is used for both CTCSS and squelch, or when an external decoder is used
for both CTCSS and the radio's squelch circuit is used. None of this is
confirmed so if you could confirm it, that would be useful.

As a test I have done: External COR w/o PL (either internal or external) = Short Sq tail, External COR w/external PL = no sq tail, DSP COR and DSP PL = Really long Sq tail. ( I have radio tune rxsquelch set to 900 and RSSI is 716).

I have noticed that when I do a radio tune rxnoise and I use DSP ctcss I get:
WARNING: Insufficient high frequency noise from receiver.
WARNING: Rx input point may be de-emphasized and not flat.
         usbradio.conf setting of 'carrierfrom=dsp' not recommended.
but when I have ctcssfrom=no it does not give the warning.

···

As a test, try using external COR and CTCSS or a combined signal and see
if that eliminates the squelch tail.

Steve
WA6ZFT

Scott Weis wrote:

Hi Scott,

There could be a couple of things that could cause this:

1. COR always asserted from the radio, and carrier detect depending on
CTCSS decode only. Check for signal swing on the COR line with a
voltmeter or a scope and make sure it swings below 0.3V and above 3V for
signal and no signal conditions.

COR no signal +12v, COR w/signal 0.0v usbradio.conf = carrierfrom=usbinvert

2. There have been reports that when external COR is used with internal
DSP CTCSS decode, that the system doesn't respond as quickly as when DSP
is used for both CTCSS and squelch, or when an external decoder is used
for both CTCSS and the radio's squelch circuit is used. None of this is
confirmed so if you could confirm it, that would be useful.

As a test I have done: External COR w/o PL (either internal or external) =
Short Sq tail, External COR w/external PL = no sq tail, DSP COR and DSP PL =
Really long Sq tail. ( I have radio tune rxsquelch set to 900 and RSSI is
716).

I have noticed that when I do a radio tune rxnoise and I use DSP ctcss I
get:
WARNING: Insufficient high frequency noise from receiver.
WARNING: Rx input point may be de-emphasized and not flat.
         usbradio.conf setting of 'carrierfrom=dsp' not recommended.
but when I have ctcssfrom=no it does not give the warning.

As a test, try using external COR and CTCSS or a combined signal and see
if that eliminates the squelch tail.

Steve
WA6ZFT

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App_rpt-users mailing list
App_rpt-users@qrvc.com
http://qrvc.com/mailman/listinfo/app_rpt-users

Hi Scott,

I wouldn't worry about this warning as far as CTCSS decode goes
as CTCSS decoding doesn't depend on high frequency noise. This sounds to
me like there could be a logic issue inside of XPMR or chan_usbradio

This warning was something which was added to the latest xpmr code be
Steve Henke, W9SH to tune the DSP code to different high frequency noise
spectra between radios.

Have you tried fully external CTCSS decode and Squelch and did that make
a difference?

Steve
WA6ZFT