New to MURS and radio using CTCSS.
Dean Galloway
I have a question about using the CTCSS part of the BTX-127. When I first
started using the radios (one connecting to another) I was not using the
CTCSS function, partly because I didn't know exactly it's function, now I
only think I have an idea.
What I'm assuming is that CTCSS splits the channel up so sharing can be done
with little interference. Would this be correct? Sort of like subnetting
the frequency?
Also, when I switched on CTCSS and set it to a tone, it seemed to take
longer for one radio to connect to another when dropping the carrier. Is
this normal when using the CTCSS function? Is this the same for all the
tone settings? I thought I saw somewhere a posting by someone (I don't
remember who or where) saying a certain setting for CTCSS would actually
make the connection of the carrier a little quicker. I am saying I THOUGHT
I saw this and I'm wondering if this is in fact the case?
Any help or advice would be greatly appreciated.
Thanks and have a good day!
dg
DxxxxxBxx
Squelch System).
Your radio is on the same channel (frequency) whether or not you use
CTCSS.
When set on, your transmitter emits a sub-audible tone at a specific
frequency. Only receivers who are set to detect that same frequency
will "open up". If you turn off your CTCSS, you will receive any
transmitter on that frequency whether they are sending a tone or not.
CTCSS is a way to keep a receiver quiet until it hears something on
its frequency AND the given tone it is set to. If each user on a
given frequency is using a different tone (38 different tones are
somewhat "standard") then each can use their radio without hearing the
other. Think of it as a party line, where each of you has his own
ring (CTCSS tone).
You may also here CTCSS referred to as a Motorola trademark "Private
Line" or PL.
Yes, my radios seem to pause for a fraction of a second before
decoding the tone and opening up the speaker. I've noticed some cheap
FRS units take up to 1/2 second before they recognize the tone and
then begin. This cuts off the first word or two of the person
transmitting if they talk as soon as they key up.
I hope I've helped some.
David
is, though the use of the CTCSS tones will filter out stations on frequency
using a different CTCSS tone you need to remember they are still using the
same frequency. I have found that if there are several stations
transmitting on the same frequency at the same time using different CTCSS
tones you won't hear their conversation but you may not be able to hear your
partner station using the same CTCSS tone. I have notice this to be the
case if me and my partner station are far apart and there is another station
much closer to me. I receive much more of the closer stations EP which
results in static.
CTCSS tones seem to work best at preventing you from hearing other stations
using the same frequency when all the stations on that frequency are not
transmitting at the same time.
On some radios this is were the monitor button comes in handy. While you
are using the CTCSS tone and notice you are not receiving your partner
station in as clearly as you expect you can press or use the monitor
function and monitor the frequency without the CTCSS filter. That way if
you hear a lot of traffic you can change frequencies.
This is the one down side of the BTX-127. It does not have an easy way to
monitor the frequency without a CTCSS tone and there is not a quick way to
change frequencies without taking off the battery cover.
BTX-127 is a good radio, especially for $30. I have 4. Also at this point
there is not a lot of traffic on the MURS frequencies. For now, the issue I
mentioned above is not a big deal. But if MURS ever becomes as used as FRS
the BTX-127's lack of a monitor button will be a larger drawback.
Anyway I tend to use my BTX in the back country while hunting and there is
not a lot of frequency traffic out there.
"DxxxxxBxx" <dDO...@lycos.com> wrote in message
news:8kpa5v4pud9avgqcs...@4ax.com...
stewart
> CTCSS.
>
Yes, the consumer radio marketers telling the public that CTCSS
(Private Line, Privacy Codes, etc.) provide 532 "sub-channels" on FRS
(or whatever) is one of the three biggest lies they tell.
The second biggest lie is that Bubble-Pack GMRS radios provide "5 mile
range".
The biggest lie is unfit to post on a "family radio" forum.
Dean Galloway
> Yes, the consumer radio marketers telling the public that CTCSS
> (Private Line, Privacy Codes, etc.) provide 532 "sub-channels" on FRS
> (or whatever) is one of the three biggest lies they tell.
>
> The second biggest lie is that Bubble-Pack GMRS radios provide "5 mile
> range".
>
> The biggest lie is unfit to post on a "family radio" forum.
Thanks for your feedback! But you have me in suspense now. :-S
What is THE biggest lie?
dg
Dean Galloway
Thanks a lot for your fast feedback! Yes your explanation was very helpful!
Have a good day!@
dg
"DxxxxxBxx" <dDO...@lycos.com> wrote in message
news:8kpa5v4pud9avgqcs...@4ax.com...
Dean Galloway
This is a very interesting addition to the previous explanation. I am
wondering though, do the HAM radio systems suffer from this same issue with
CTCSS?
Oh BTW, I have never considered an FRS set of radios, 1/2 a watt reminds me
of the old Radio Shack walkie talkies that were lucky to reach to the end of
a short street.
I have another question though, do radios (let's use the BTX-127 as an
example because I have two of them) actually benefit from extended range
using the CTCSS option or is it just less noise received? I suppose I'm
thinking back to the old days where little or no traffic on the channel
meant you could carry on a conversation with a distant station simply
because there was nobody closer with a better signal. Assuming the channel
is fairly clear, with CTCSS handling the squelch, does this offer and
improved range even though someone else may be sharing the frequency but
using a different tone? Again let's assume the channel is fairly clear and
not packed with different people using different tones..
Am I explaining this the right way??
Thanks!
dg
"David" <davidm...@earthlink.net> wrote in message
news:8rg5a.12413$_c6.1...@newsread2.prod.itd.earthlink.net...
Randy A. Hefner
>
> Oh BTW, I have never considered an FRS set of radios, 1/2 a watt reminds me
> of the old Radio Shack walkie talkies that were lucky to reach to the end of
> a short street.
>
How about 130 miles. Is that at "short street"?
David
limited. Somebody who has really studied the science behind radio
communication can give you a better answer. My comments are largely based
on a small amount of technical knowledge and a lot of testing in the field.
Anyway, regarding your question if this issue applies to HAM's. I can only
say that in theory it could happen but in practice due to a number of
reasons it won't in the HAM setting.
i.e.. On MURS, stations are operating in simplex with a limited number of
frequencies. The likelihood of stations transmitting at the same time is
increased. In the HAM community, each HAM band has a much larger band width
allocated to it and each band has a band plan. Certain channels are allotted
to simplex and certain channels are allotted for repeaters, etc. I live in
the SF Bay Area and most of the traffic is through repeaters. Due to the
band plan (generally) you will not have stations transmitting on a repeater
input frequency in simplex. Stations who use the repeater input frequency
know it is a repeater and also know the PL (CTCSS) tone. Their intent is to
communicate through the repeater. Its possible that a station could use the
repeater input frequency with a different PL tone in simplex mode but their
would be no point in doing it as there is plenty of simplex frequencies
allocated to simplex.
Now your question about CTCSS and range. I can only say that in practical
in-field situations the use of CTCSS tones on a clear frequency is not going
to add or subtract from your range in any noticeable degree. I find that
antenna height, terrain, equipment, power output (to a smaller degree) are
more likely to affect ranch in real in-field use. However common sense
logic and my in field experience tell me that the more complicated we make
the receivers job to hear a station the less range we will have. i.e.. With
the CTCSS on, the receiver needs to hear the audible signal and hear the
sub-audible CTCSS tone before the mike breaks open. I liken it to using the
squelch knob. If you have the squelch off you will get more range from your
receiver but you give up clarity. And who wants to walk around with an HT
on their belt with the squelch wide open making a loud static noise on the
off chance your partner station wants to communicate with you at the very
outer limits of your range. Now I have done that is certain situations.
For example while hunting. My partner and I will give a specific time to
attempt communication. And remember RANGE is a function of both the
transmitter and the receiver. In the hunting situation, at the agreed upon
time my partner and I will try to position ourselves as high on a hill as
we practically can, turn off the CTCSS tone, turn down the squelch, use the
highest power setting. To the extent we can maximize these elements we
increases our range while using our BTX-127's.
"Dean Galloway" <dean.g...@earthlink.net> wrote in message
news:5Xh5a.14169$YU4.1...@newsread1.prod.itd.earthlink.net...
Phil
> Hi everyone,
>
<snip>
> Also, when I switched on CTCSS and set it to a tone, it seemed to take
> longer for one radio to connect to another when dropping the carrier. Is
> this normal when using the CTCSS function? Is this the same for all the
> tone settings? I thought I saw somewhere a posting by someone (I don't
> remember who or where) saying a certain setting for CTCSS would actually
> make the connection of the carrier a little quicker. I am saying I
THOUGHT
> I saw this and I'm wondering if this is in fact the case?
> dg
Somebody please correct me if I'm wrong, but as far as CTCSS tones slowing
down connection speed, I seem to remember reading that of the 38 tones, the
first 6 and the last 8 ( the lowest and highest freq. tones) require a
longer time to "connect" with the corresponding radio you are trying to
communicate with?
This may require you to hold down the transmit button for a full second or
two before speaking?
For some reason tones #7-30 connect quicker?
Is this accurate?
Phil