| Author |
Message |
    
San Diego Mark (Unregistered Guest)
Unregistered guest
| | Posted on Thursday, June 10, 2004 - 9:47 pm: | 
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Hello all,
I am studying to get my ham ticket and have my eye on the new Yaesu VX-7R. I got to thinking that with the CTCSS codes if two guys wanted to use those radios just between themselves like hunting buddies or jobsite radios they could program the CTCSS codes so that only those 2 or 3 or however many radios you want for that matter could only communicate with each other thus making the need for a license to operate them pointless. I know legaly you have to have the ticket but who in the world would ever be bothered or even hear you to make a complaint? Now don't get me wrong I am still getting my ticket the studying is a breeze, actually enjoyable, I might just go give the test a shot this Saturday after starting the Gordon West book just last night. This little revalation has me very interested though as I would like on occasion to be able to have my wife be able to get ahold of me on a 2 meter radio in rural Texas where we will be moving to that has poor cellular coverage, she would never study to pass the tech license exam! Thanks...
Mark, San Diego, Ca. |
That ELCO Guy (Unregistered Guest)
Unregistered guest
| | Posted on Friday, June 11, 2004 - 8:12 am: |
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@ Mark
The purpose of the Ham License is to legally authorize you to use certain radio frequencies.
But more specificly in your example, the tone access does not prohibit you from talking to other units. Think of the tone as a big squelch. You will hear the buddies you want to talk to but not those who you do not wish to talk to.
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San Diego Mark (Unregistered Guest)
Unregistered guest
| | Posted on Friday, June 11, 2004 - 8:49 am: |
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I know what the license is all about, my thinking is based on what I have read in my manual for my MURS radio regarding CTCSS codes and it says that if my radio has been set to a CTCSS code any other radio I wish to communicate with must be set at that code. What is the point of having these privacy codes if anyone else monitoring a freq say in the 144-148 range can hear you? The bottom line question is if there are three radios set to freq 144.05 but two of them have a CTCSS code set in, can the third radio hear the two that are coded communicate?
Mark |
Tech237
Moderator
Username: Tech237
Post Number: 36
Registered: 4-2004
| | Posted on Friday, June 11, 2004 - 9:26 am: |
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Mark,
Anyone monitoring that frequency that isnt running CTCSS tones will hear you. CTCSS tones only prevent the radio that has tones set form hearing other users on that frequency that aren't running tones or running a different tone.
To answer your bottom line Yes it will hear you, and by the way 144.05 is not used for voice but digital modes - including CW. |
Pig040
Intermediate Member
Username: Pig040
Post Number: 457
Registered: 7-2003
| | Posted on Friday, June 11, 2004 - 10:04 am: |
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Anyone with a radio on scan that covers thos freqs will be able to pick up the transmissions. I use my radio on scan every once in a while, pick up whatever is on the freq.
Rich |
Highlander
Advanced Member
Username: Highlander
Post Number: 529
Registered: 12-2001
| | Posted on Friday, June 11, 2004 - 10:31 am: |
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Yes.
The purpose is so that you won't hear others on the frequency, not so that they cannot hear you. You are looking at it backwards. |
Tech808
Moderator
Username: Tech808
Post Number: 2641
Registered: 8-2002
| | Posted on Friday, June 11, 2004 - 12:07 pm: |
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For Reference:
http://www.arrl.org/FandES/field/regulations/allocate.html
2 Meters
All Amateurs except Novices:
144.0-144.1 MHz: CW Only
144.1-148.0 MHz: CW, Phone, Image, MCW, RTTY/Data
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San Diego Mark (Unregistered Guest)
Unregistered guest
| | Posted on Friday, June 11, 2004 - 7:28 pm: |
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Thanks guys, I tried it today by setting my radio on a ctcss code and calling one of my workers. He could hear me but I could'nt hear his reply, I guess this would be good if our area was saturated with MURS users, the other day we switched from channel 3 down to 2 because of a lot of traffic from another construction site. My bad on the 144.05 only for CW, I remember reading that in the book now, I hope that if I was reading a question on that I would have remembered.
Mark |
Sarge
Junior Member
Username: Sarge
Post Number: 15
Registered: 11-2003
| | Posted on Sunday, June 13, 2004 - 4:51 am: |
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This is similar to the old advertising claim by Radio Shack and others that their 40-channel SSB CB radios actually had "120-channels".
Take Channel 36 for example...
It doesn't matter whether you are using AM, USB, or LSB, you are still using the same frequency/channel. The two guys using LSB will probably detect the presence of the other two guys running USB on the same channel/frequency. And they will ALL hear the guy who tries to contact a buddy by shouting on AM. No matter what mode you are running, everyone is still trying to talk on the same frequency at the same time.
CTCSS is great for crowded business band frequencies that are being shared between different companies. It allows your workers to concentrate on their job without hearing all the radio chatter from the other unrelated job sites.
If you have ever wondered why Motorola radios are often installed with a grounded microphone holder clip, it's for this exact situation. When the hand mic is hung up on the mic holder the radio is in CTCSS squelch mode. But as soon as you unground the hand mic by removing it from the mic holder the radio switches to "open squelch" or "carrier operated squelch". This is so you can hear all the other users on the frequency. It allows you to ensure the frequency is clear before you attempt to use it. Otherwise everyone would be stepping on each other's transmissions and nothing would get accomplished (sort of like Ch 19 on a bad day...)
In the Air Force this feature is used on the 2-way radios installed in the snow plows used to clear the runways. They are operating on the same Civil Engineering frequency as everyone else, but the CTCSS allows them to concentrate on their job instead of listening to the plumber describing the problem he is having with a backed-up toilet in the barracks. The Control Tower also has CTCSS enabled so the only chatter they hear is from the snow plows clearing the runway, not the other crews clearing the base streets.
CTCSS can be a usefull tool if you know what it's limitations are. As was mentioned previously, Hams often use CTCSS on repeaters to prevent stray signals from inadvertently keying up the repeater. This is especially true when the ham repeater is co-located at a commercial site hosting lots of other business band repeaters. There can be many strong RF signals floating around the site, and although not in the 2-meter band, some can be strong enough to trigger the ham repeater by making it think it is hearing a weak 2-meter signal when actually it is a strong signal on a nearby VHF business frequency. This is when using CTCSS can be a big help! |
Geekster
New member
Username: Geekster
Post Number: 2
Registered: 6-2004
| | Posted on Tuesday, June 15, 2004 - 12:08 pm: |
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I think within there is like a paging feature with this tone. It has been awhile since I used it tho.
MURS... wow I am really interested in getting started but can't find any activity on the frequencies yet. |
Tech808
Moderator
Username: Tech808
Post Number: 2664
Registered: 8-2002
| | Posted on Tuesday, June 15, 2004 - 5:12 pm: |
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Geekster,
Around here (Central Illinois) MURS took off with a Bang and has slowley died down to almost nothing.
We still have a few around that use MURS but very few.
Lon
Tech808 |
