[chirp_users] Tone Settings TX, RX (TSQL & DCL) discussion

[Forrest]

Thanks for the follow-up, Bill.  While I do have a Tech license, more often I’m involved in public safety communications and just as you say, we look to to exclude signals (on the same freq) by way of tone squelch.  As you know, these signals, while often distant geographically, will come in via skip or even direct sometimes and involve many thousands of watts and can disrupt what you’re trying to accomplish locally.

We were looking at the same issue from different standpoints and it just hadn’t occurred to me to say ‘not recommended’ involving use of tone or DCS on receive.  It boils down to ‘it depends’.  :)

Regards,
Forrest

On Jul 22, 2014, at 12:29 PM, Bill Kasper <williamkasper at frontiernet.net> wrote:

> Hi Forrest et al,
> 
> The TX tone (CTCSS DCL and other names) may be required
> for the ham repeaters that use it. Modern radios' menus
> may set the tone independently for each channel or
> for the entire rig. This tells the repeater that
> "I really want to talk thru you" and I'm not some
> skip-signal coming from a different part of the country.
> 
> Historically (a hundred years ago?) commercial repeaters
> had several to many business users on them, as they were
> expensive and each business that used, ie. paid for the
> repeater service, had a different tone to open only that
> businesses own radios: a taxi had one tone, the road-repair
> company another tone, and the delivery company another tone
> and so on. They had to share the resource (the repeater) and not 
> interfere with each other any more than necessary. CTCSS is the
> modern technical name of that tone process that used to be
> called PL - Private Line (Motorola), CG - Channel Guard,
> General Electric, and privacy codes for various FRS radios,
> plus other names.
> 
> It is the tone ENGAGED on the RECEIVER end that can be
> problematic: the exact tone MUST be present on the
> transmitted signal for the receiver squelch (TSQL)
> to open so you can hear the other station on that
> frequency; which may or may not be what you want.
> 
> As an example, I setup a simplex ham voice channel
> for myself and XYL to use as a 'Private Line'
> (Motorola trademark) only for us: car-house, car-car
> etc. This is fine for us, and I have TSQL set on both
> radios for this channel. On this 'unused' simplex
> channel she can only hear me and I can only hear her.
> If someone else hears us, which they could, and then
> tries to answer me, I would not hear them unless they
> figured out and then transmitted our 'PL' tone.
> 
> As an aside, this feature, as implemented on the FRS
> private channel radios, means that you can only hear
> people transmitting your private code on your channel;
> people with no (RX) tone set can hear you too, so not
> really very private, but helps reduce chatter from
> other users when listening on a shared resource/channel.
> The implication is that, if you use your FRS channel 1,
> by convention, as an emergency receiver, make sure the
> privacy codes are turned off, so you will be able to
> hear everyone on channel 1, even if they have a privacy
> tone enabled.
> 
> other comments?
> 
> 73 de Bill WB2SXY
> 
> --
> 
> On 7/22/2014 12:26 PM, Forrest wrote:
>> Curious why you say that using tone squelch on both TX and RX is not recommended???
>> 
>> THX.
>> Forrest
>> 
>> On Jul 21, 2014, at 6:51 PM, John LaMartina<JohnLa at usa.net>  wrote:
>> 
>>> Yes, TSQL sets the CTCSS or DCS tone on both TX and RX. (Not Recommended).
>>> Tone sets CTCSS or DCS on TX only.
>>> This explains in a bit more detail. http://www.miklor.com/COM/UV_CTCSS.php
>>> I hope this helps...
>>> 
>>> John K3NXU
>>> http://www.miklor.com
>>> 
>>> 
>>> -----Original Message-----
>>> From: chirp_users-bounces at intrepid.danplanet.com [mailto:chirp_users-bounces at intrepid.danplanet.com] On Behalf Of Dave Nathanson
>>> Sent: Monday, July 21, 2014 7:22 PM
>>> To: Discussion of CHIRP
>>> Subject: Re: [chirp_users] Settings
>>> 
>>> Someone else will hopefully correct me if I'm wrong, (and I didn't look this up) but I believe that in this usage, "Tone" applies
>>> when transmitting only.
>>> TSQL, or Tone Squelch applies to both transmitting&  receiving.
>>> 
>>> "Tone" is more common.
>>> If you use TSQL when you should have used Tone, others will be able to hear you, but you will only be able to hear them if they also
>>> use the same tone.
>>> To complicate things slightly, many repeaters require a tone to activate them, but many repeaters strip out the tone as the
>>> re-transmit.
>>> It is often a good idea to start with "tone" and only use TSQL if needed.
>>> 
>>> Best,
>>> Dave Nathanson
>>> KG6ZJO
>>> 
> 
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