[chirp_users] Thoughts after looking at the most recent build

[Ron McKenzie]

Bob,

Thanks for the education. For a short time, back about 1978 to 1981, I 
converted a Motoroal base station into the first 147.61 repeater for 
Vail, CO. I seem to recall that PL was just beginning to be used by some 
PDs in Denver but none of the ones in my area of the Western Slope. From 
1981 until recently, I've been away from ham radio and not following 
current developments and the evolution of practices.

So, some more questions. Use of CTCSS or DCS is a "local option" and the 
decision to use it on a repeater's retransmission is a separate local 
decision. Using the same PL tone (or DCS code) on the repeater's input 
and output has evolved into a "usual and customary practice" and is not 
a requirement. Further, it is used in an attempt to restrict a repeater 
to only retransmitting signals that are really intended for it and its 
users. Adding that tone or code to the repeater's output merely adds 
value for the user since spurious signals on the repeaters output freq 
are "hidden".

Further, many of the UHF/VHF ham radio manufacturers have built the 
usual and customary practices re: CTCSS tone/DCS code use into their 
radios to simplify circuit design and complexity. The consequence is 
that it reinforces the usual and customary practices. An unintended 
consequence is that users assume that the usual and customary is an 
absolute, immutable rule. It alsomakes life substantially more difficult 
for the admin/operator who needs to use different CTSS tones or DCS 
codes on a repeater's input and output frequencies. I know of a system 
(Colorado Connection) where there are a few VHF-VHF links in a larger 
system.

Have I captured the gist of the matter, Bob?

Again, thanks for the explanation. After I sort out a few more "things" 
I'm going to become more active around here and try to meet some of the 
folks who maintain local repeaters. As an aside, one thing that puzzle2 
s me is the general lack of traffic that I hear. One of those "things" 
is building or buying better antennas for my QTH (covenant-restricted 
subdivison) and my van.

73 de KK4DBR, Ron
EL98fk    Windermere, Orange Cty, Florida
living in the massive shadow of a wee rodent



On 8/9/2011 11:19 AM, Robert Terzi wrote:
> On 8/9/2011 9:45 AM, Dan Smith wrote:
>> On 8/9/2011 12:49 AM, Ron McKenzie wrote:
>>> [...]
>>> Some questions to help increase my knowledge of current practices:
>>> [...]
>>> 2. Is a repeater operator precluded from selecting different CTSS or
>>> DTCCS codes for Rx and Tx?
>> Yes, at the moment.
>
> Err, perhaps repeater operator is a bit ambiguous here?
>
> The repeater owner/administrator, who configures the repeater can
> can set up a repeater with different tone or digital squelcn
> settings for transmit / receive.  The occurrences of this are
> pretty rare, and a number of popular radios do not support the
> setting of different squelch encoding / decoding on the same
> memory channel.  However, I've seen a couple of popular linked
> repeater systems in the NYC area move to this configuration
> to avoid interference.
>
> Also, I'm going to take the risk of being a bit pedantic here
> since I've seen a lot of misunderstanding on different mailing lists.
>
> CTCSS, Aka Tone Squelch, or PL (Private Line) is a method for
> including an analog tone in a transmitted signal in order to
> allow the receiver to operated in a mode where it will only
> open the squelch if the tone is present.  This prevents noise or
> even other undesired signals from being heard.
>
> DCS, Digital Coded Squelch, uses a digital code embedded in
> the transmitted signal that provides for more possible squelch
> codes and greater reduction in an unwanted signal opening the
> receiver's squelch.
>
> The typical repeater setup (especially in the US) is that the
> repeater's receiver has a tone squelch setup to prevent the repeater
> from keying up on unwanted noise or signals.  This means that in order
> to use the repeater, your radio must *encode* the squelch tone in your
> transmission.
>
> The repeater when retransmitting a signal may encode a squelch
> tone or digital code.  This is a feature for the convenience of
> the people who listen to repeater to provided added protection
> against hearing unwanted noise or signals.  None of the receive
> squelch settings on your end are required to use the repeater
> and if set incorrectly can prevent you from hearing the repeater.
> Given that it is often best to make sure you've got the settings
> for the repeater working correctly before you enable any receive
> squelch settings for that memory.  If you don't live in a noisy
> area you could skip that step entirely.
>
> About half of the repeaters that I've come across do transmit
> tone squelch which makes monitoring and scanning that much
> more pleasant.  I've only come across three repeaters in my area
> so far that use DCS.
>
> The most of the non-typical setups I've seen are from linked
> repeater systems in areas that are densely packed with radios.
>
> Hope This Helps,
> --Rob
>
>
>
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