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Old 05-17-2017, 2:11 PM
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Default + - offset and other questions.

Ok, I have dumbed down in my old age. This site use to list the frequencies and if it was a + or -. Or at least I thought it did. I understand that the 440 is pretty much always going to be a +, but how do I determine it for each band? Like something in the 144-148 range.

Is there a site, aside from this one that would list all that info for a given frequency?

Could use a refresher on what determines the offset for ham frequencies.

I had everything programmed in and got tired of the order and naming I used and reset the whole radio. Now I am not transmitting. I am certain I am just screwing up the channel setup.

Oh yeah, and how the heck do I tell myself if it is T or CT when setting up a channel? In regards to making a quick check on here, and it just lists the PL Tone, how do I decide if it is T or CT based off the info this site lists when looking up a frequency.

Thank for the help.
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Old 05-17-2017, 2:13 PM
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https://wiki.radioreference.com/index.php/Offset shows offsets for the ham bands.
For ham repeaters in Oklahoma see http://www.oklahomarepeatersociety.org/repeaters

I don't know what you mean by T and CT. That depends on what radio you are trying to program.
If it's a Yaesu then T is PL encode only and CT is PL encode and decode.
Normally for ham repeaters you set it to T and program the PL tone frequency. Decode isn't normally necessary.
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Old 05-17-2017, 2:18 PM
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Thanks Tom!
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Old 05-17-2017, 2:23 PM
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Also, one of the frequencies I had setup yesterday an was actually talking on, now I can't get to work. So I go back and look it up here and it shows it has a DPL. I can't do digital on my radio, but there must be a PL also, since I was using this freq with no problems. Do I just need to look it up thru the FCC database?
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Old 05-17-2017, 2:32 PM
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DPL is the same as DCS https://wiki.radioreference.com/index.php/DCS
It's not a tone it's a digital data stream.
The FCC database does not contain PL tones or DCS codes.
Is this for a ham repeater?
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Old 05-17-2017, 2:36 PM
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Quote:
Originally Posted by okccsi View Post
Oh yeah, and how the heck do I tell myself if it is T or CT when setting up a channel? In regards to making a quick check on here, and it just lists the PL Tone, how do I decide if it is T or CT based off the info this site lists when looking up a frequency.

Thank for the help.
Don Manning
I am not sure what you mean by T or CT. It must be some abbreviations specific your particular transceiver. I suspect you'll have to consult the documentation for your radio to verify what they mean by T and CT.

PL or TPL or CTCSS tones (all the same thing) are usually a number with one decimal place like 141.3. It is an actual tone frequency measured in Hz, too low to be heard by most humans and usually referred to as sub-audible tones. There's also a code assigned to most TPL; 141.3 can be expressed as 4A. In the RR db, it is usually listed as 141.3 PL

DPL is digital coded squelch (also known as DCS) and expressed as 3 digit numbers. In the RR db, it's usually xxx DPL.

Here's a pretty good breakdown of it all: Two-way Radio CTCSS and DCS Codes At the bottom of that page, there is a link to a pdf that contains info on many of the common tone schemes, both sub-audible and the audible ones commonly used for paging, etc. That document has been in the front of my main reference binder for many years.
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Old 05-17-2017, 2:36 PM
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Yes. On here it is listed a 712 DPL, but since my radio doesn't do DPL, there has to be a regular tone. And, how do I determine if it is T or CT from what this website lists?
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Old 05-17-2017, 2:38 PM
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T is for Tone and CT is for CTCSS
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Old 05-17-2017, 2:41 PM
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Quote:
Originally Posted by okccsi View Post
Yes. On here it is listed a 712 DPL, but since my radio doesn't do DPL, there has to be a regular tone. And, how do I determine if it is T or CT from what this website lists?
712 a DCS code. There is no "regular tone". If your radio doesn't have DCS then you can't program it.
What radio are you trying to program and what web page did you get the 712 DPL from?
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Old 05-17-2017, 2:46 PM
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712 a DCS code. There is no "regular tone". If your radio doesn't have DCS then you can't program it.
What radio are you trying to program and what web page did you get the 712 DPL from?
On this website, RR.com, the frequency is 145.1100 and it says 712 DPL for the tone. I could swear I was using this repeater yesterday, meaning I had it programmed in a long time ago. I am using a Kenwood TM-G707 and it does not do DPL.

Frequency Type Tone Out Tone In
147.1100 RM 712 DPL 712 DPL
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Old 05-17-2017, 3:54 PM
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DPL and DCS are to-may-to and to-mat-o... just as PL and CTCSS are..
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Old 05-17-2017, 4:30 PM
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Quote:
Originally Posted by okccsi View Post
Oh yeah, and how the heck do I tell myself if it is T or CT when setting up a channel? In regards to making a quick check on here, and it just lists the PL Tone, how do I decide if it is T or CT based off the info this site lists when looking up a frequency.
T generally indicates that you're transmitting a tone from your radio to the repeater.

CT generally indicates that your not only transmitting a tone from your radio to the repeater, but your radio will also require that tone to be sent back to you for you to receive the signal.

If the repeater you're using requires a tone you'll need to at least have your radio set to "T" for things to work for you. "CT" may work as well since many repeaters will transmit that same tone back to the user (this isn't always the case however). There are even some repeaters that require one tone from the user and will transmit a different tone back to the user, but these aren't too common and normally this will be made clear on the listings for that repeater. Don't worry too much though if your radio won't allow different tones to be set since this is easily handled (see the next paragraph on that).

The need for you to have a tone set on receive is pretty much optional so if you aren't sure about setting a receive tone, simply leave it set for transmit only. This is also a way to handle the repeaters that have different transmit and receive tones if your radio can't be programmed for that. A receive tone can be thought of as a filter. If you have a receive tone set on your radio, you'll only hear stations that broadcast that specific tone, all others will be muted (as in they send a different tone or send no tone at all). It's a useful feature if you have interference from other repeaters that you don't want to hear (and use a different tone) or interference from other signals that make listening unpleasant (such as leakage from cable tv lines, etc.) that won't have the correct tone on their signal. Most digital modes do not transmit a tone so it can be useful to have a tone set on a mixed mode repeater that in analog mode transmits a tone but in digital mode does not as this will prevent you from hearing the digital noise when it's being used in digital mode.

That filter affect is often why a repeater will require a tone. Since they're on tall towers, tall buildings, or other locations that allow them to hear stations from long distances, the tone will help them retransmit only stations that intend for them to retransmit their signals. They may hear stations on the same frequency attempting to use other repeaters and assuming that the tones are different, they will not retransmit them.

Having your radio use a receive tone may cause you issues in some situations. The most problematic one is that some repeaters drop the tone requirement during emergency nets such as Skywarn nets. This is to allow folks that have old radios without tone capability to participate and weak signals may not have sufficient signal to let the repeater lock onto the tone, but they may have important information for that net. Also some repeater operators allow use of their output for simplex operation at times when the repeater isn't operational (often during those same emergency nets) as a backup mode. Many operators do not send a tone when operating simplex (although there's generally no harm in doing so) and if you require a tone, you won't pick up their transmissions.
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Old 05-18-2017, 12:49 AM
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Quote:
Originally Posted by okccsi View Post
On this website, RR.com, the frequency is 145.1100 and it says 712 DPL for the tone. I could swear I was using this repeater yesterday, meaning I had it programmed in a long time ago. I am using a Kenwood TM-G707 and it does not do DPL.

Frequency Type Tone Out Tone In
147.1100 RM 712 DPL 712 DPL
It is entirely possible that the person/club that owns the repeater changed from a CTCSS/PL to a DCS/DPL overnight. This could be for any number of reasons. You would need to contact the person/club to find out why.

Otherwise, you are just simply out of luck, if your radio isn't capable of DCS/DPL operation.

-----

One or two others here have questioned what "T" and "CT" mean. On my Icom IC W-32A handheld, a "T" on the display means that I have a tone set for transmit only. A "CT" means that I have a tone set for both transmit and receive. Your radio display may show this differently.

-----

BTW, not all 70cm repeaters have a + offset. Here in Arizona, there is a mix of + and -. Do a search on your state repeater coordination group. (There may be more than one, each covering a different area of the state.) They should have lists available of all the coordinated repeaters, with frequency, tone, and other info, available to you.

John
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Last edited by KB7MIB; 05-18-2017 at 12:55 AM..
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Old 05-18-2017, 6:00 AM
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Likely Tone is Transmit CTCSS and CT is Transmit/Receive Tone.

Older Amateur Radios only used Tone on the input [Transmit side]

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T is for Tone and CT is for CTCSS
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Old 05-18-2017, 6:52 AM
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Quote:
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T is for Tone and CT is for CTCSS
Just in short form...

All though manufacturers are free to use what every indicators they choose, the above makes sense.

T for tone, means the transmitter of the radio in use will transmit the selected tone to the repeater.

CT is short for CTCSS, as mentioned continuous tone coded squelch, as in the squelch in the radio in use, not the repeater, the T=tone takes care of the receive side of the repeater, because the radio in use is transmitting the necessary tone.

If the repeater transmits a tone then CT=CTCSS, is operative, giving tone control to the squelch of the radio in use.

Then we move away from the analog realm. This has already been well explained.
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Old 05-18-2017, 10:53 AM
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Quote:
Originally Posted by okccsi View Post
On this website, RR.com, the frequency is 145.1100 and it says 712 DPL for the tone. I could swear I was using this repeater yesterday, meaning I had it programmed in a long time ago. I am using a Kenwood TM-G707 and it does not do DPL.

Frequency Type Tone Out Tone In
147.1100 RM 712 DPL 712 DPL
Since your radio doesn't do DPL/DCS, which is different than CTCSS/T>transmit side/CT>transmit and receive. You will not be able to access the repeater.
You will need to get another radio that does CTCSS and DCS. No other way around it.
Larry
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Old 05-18-2017, 11:08 AM
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I was able to key up the 145.11 - DPL 712 repeater this morning. It's about 80 or 90 miles north of here.
It was encoding DPL 712 on the output. Maybe the input is CSQ. I didn't think to turn the tone off and see if I could still key it up.
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Old 05-18-2017, 3:02 PM
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for future reference, the band 'plans' for 440 call for repeaters with output between 440 and 445 to have an offset of +5 MHZ and from 445 to 450 to be -5 MHZ. the standard offset on 144 is 0.600 Mhz. 147 Mhz output is + offset and 146 is -. I think the 145 repeaters are - offset but have not used many so memory may be failing.

Most modern radios do both tone (or CTCSS) and DPL. Most alos have a way to 'find' the tone by monitoring the output. The 'tone search' function is often 'buried' in the menu system somewhere, making it hard to use while driving. I would suggest you read the manual for your rig. Most manufacturers websites have PDF manuals of radios if you can't find yours. Googling <radio model> and manual works well too-found manuals for radios 20+ years old that way.

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Old 05-18-2017, 4:05 PM
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You should also know that, especially in 2m, those - or + offsets may be "standard" in a particular area of the band but are not mandatory. Occasionally, the - area may have a + offset and vice versa.

Most do follow the standard and even the RT programming software uses the "standard" as a default in programming the - or +, although it can be changed.
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