PL tone removal?
$begingroup$
How are PL tones (CTSS, et.al.) typically removed from the audio of received VHF FM repeater signals?
Is it done with a fixed high-pass filter? Or a notch, when using a transceiver with the PL tone configured correctly? Or dynamically, by assuming any constant low tone detected is hum to be removed by an auto-adaptive notch?
Or is it sometimes not removed by filtering because the tiny speakers on handheld receivers don't have sufficient low frequency response?
tone-squelch
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
$endgroup$
add a comment |
$begingroup$
How are PL tones (CTSS, et.al.) typically removed from the audio of received VHF FM repeater signals?
Is it done with a fixed high-pass filter? Or a notch, when using a transceiver with the PL tone configured correctly? Or dynamically, by assuming any constant low tone detected is hum to be removed by an auto-adaptive notch?
Or is it sometimes not removed by filtering because the tiny speakers on handheld receivers don't have sufficient low frequency response?
tone-squelch
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
$endgroup$
add a comment |
$begingroup$
How are PL tones (CTSS, et.al.) typically removed from the audio of received VHF FM repeater signals?
Is it done with a fixed high-pass filter? Or a notch, when using a transceiver with the PL tone configured correctly? Or dynamically, by assuming any constant low tone detected is hum to be removed by an auto-adaptive notch?
Or is it sometimes not removed by filtering because the tiny speakers on handheld receivers don't have sufficient low frequency response?
tone-squelch
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
$endgroup$
How are PL tones (CTSS, et.al.) typically removed from the audio of received VHF FM repeater signals?
Is it done with a fixed high-pass filter? Or a notch, when using a transceiver with the PL tone configured correctly? Or dynamically, by assuming any constant low tone detected is hum to be removed by an auto-adaptive notch?
Or is it sometimes not removed by filtering because the tiny speakers on handheld receivers don't have sufficient low frequency response?
tone-squelch
tone-squelch
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
asked 12 hours ago
hotpaw2hotpaw2
3,17321733
3,17321733
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
I would expect some low-frequency roll-off in the amp and the speaker. You could check by putting headphones on the speaker output.
Wikipedia says that a 300 Hz cutoff high-pass filter is common.
https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System
Also, the CTSS tone is injected at a lower level than the voice content, usually 15% of full deviation. That is about 8 dB below full modulation.
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
return StackExchange.using("schematics", function () {
StackExchange.schematics.init();
});
}, "cicuitlab");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "520"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fham.stackexchange.com%2fquestions%2f13019%2fpl-tone-removal%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
I would expect some low-frequency roll-off in the amp and the speaker. You could check by putting headphones on the speaker output.
Wikipedia says that a 300 Hz cutoff high-pass filter is common.
https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System
Also, the CTSS tone is injected at a lower level than the voice content, usually 15% of full deviation. That is about 8 dB below full modulation.
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
$endgroup$
add a comment |
$begingroup$
I would expect some low-frequency roll-off in the amp and the speaker. You could check by putting headphones on the speaker output.
Wikipedia says that a 300 Hz cutoff high-pass filter is common.
https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System
Also, the CTSS tone is injected at a lower level than the voice content, usually 15% of full deviation. That is about 8 dB below full modulation.
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
$endgroup$
add a comment |
$begingroup$
I would expect some low-frequency roll-off in the amp and the speaker. You could check by putting headphones on the speaker output.
Wikipedia says that a 300 Hz cutoff high-pass filter is common.
https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System
Also, the CTSS tone is injected at a lower level than the voice content, usually 15% of full deviation. That is about 8 dB below full modulation.
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
$endgroup$
I would expect some low-frequency roll-off in the amp and the speaker. You could check by putting headphones on the speaker output.
Wikipedia says that a 300 Hz cutoff high-pass filter is common.
https://en.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System
Also, the CTSS tone is injected at a lower level than the voice content, usually 15% of full deviation. That is about 8 dB below full modulation.
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
answered 10 hours ago
Walter Underwood K6WRUWalter Underwood K6WRU
1,685712
1,685712
add a comment |
add a comment |
Thanks for contributing an answer to Amateur Radio Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fham.stackexchange.com%2fquestions%2f13019%2fpl-tone-removal%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
