CTCSS and DCS, Does it make a difference?

[WSAH786]

Good morning ole' wise members of knowledge.

When it comes to configuring tones for a repeater, does it matter whether I use CTCSS or DCS tones. My repeater will do either and I currently have it set up for a CTCSS tone, both broadcast and receive. Are there pros and cons to using either? Or just personal preference? 

[WRXP381]

6 minutes ago, WSAH786 said:

Good morning ole' wise members of knowledge.

When it comes to configuring tones for a repeater, does it matter whether I use CTCSS or DCS tones. My repeater will do either and I currently have it set up for a CTCSS tone, both broadcast and receive. Are there pros and cons to using either? Or just personal preference? 

Some radios cheap, older, ect do not do digital tones so that may help make a decision. I think it’s more important to have cross tones so the input is different than the output.  That way it’s harder for some one to scan and get your input tone if that’s something you care about. 

[nokones]

14 minutes ago, WRXP381 said:

Some radios cheap, older, ect do not do digital tones so that may help make a decision. I think it’s more important to have cross tones so the input is different than the output.  That way it’s harder for some one to scan and get your input tone if that’s something you care about. 

In some cases helps to prevent intermod interference from your own station

[TrikeRadio]

Besides some older radios not being able to use DCS...
Are there any other real differences? Is DCS possibly more reliable or able to overcome static or interference more so than CTCSS ?

[OffRoaderX]

20 minutes ago, TrikeRadio said:

Besides some older radios not being able to use DCS...
Are there any other real differences? Is DCS possibly more reliable or able to overcome static or interference more so than CTCSS ?

There are technical differences, but I have never observed any actual, real-world difference - in the real-world, they both do the job just fine.

also, FYI, I have owned/used virtually every GMRS radio manufactured since ~2017 and I do not recall ever seeing one that does not support DPL/DTC/DCS tones.  Not saying those radios do not exist, but if they do, they are very old, very rare, or, both.

[WSAH786]

1 hour ago, nokones said:

In some cases helps to prevent intermod interference from your own station

Can you elaborate on that? I have two antennas in my attic (HOA). Both are TRAM 1486's separated by 15ft. One attached to a repeater/duplexer and the other to my KG1000+ (used as a base). I have wondered if the base would interfere with the repeater antenna while on deferent frequencies. Obviously, I don't use the base to hit my own repeater but would it interfere with someone trying to use the repeater at the same time? Or is this a totally different question?

[LeoG]

Good chance that when you are transmitting on your radio your repeater goes deaf and vice versa.  That's a lot of rejection needed.

[SteveShannon]

On 8/28/2024 at 12:08 PM, WSAH786 said:

Can you elaborate on that? I have two antennas in my attic (HOA). Both are TRAM 1486's separated by 15ft. One attached to a repeater/duplexer and the other to my KG1000+ (used as a base). I have wondered if the base would interfere with the repeater antenna while on deferent frequencies. Obviously, I don't use the base to hit my own repeater but would it interfere with someone trying to use the repeater at the same time? Or is this a totally different question?

 

7 minutes ago, LeoG said:

Good chance that when you are transmitting on your radio your repeater goes deaf and vice versa.  That's a lot of rejection needed.

If you're transmitting on the 462 MHz main channels from your KG1000, your duplexer and repeater must be able to reject it, or it couldn't function as a full duplex repeater.

If you're transmitting on the 467 MHz main channels that are the input channels for the repeater, then I agree with Leo, you could interfere with reception at the repeater.

[WSAH786]

On 8/29/2024 at 5:28 PM, SteveShannon said:

 

If you're transmitting on the 462 MHz main channels from your KG1000, your duplexer and repeater must be able to reject it, or it couldn't function as a full duplex repeater.

If you're transmitting on the 467 MHz main channels that are the input channels for the repeater, then I agree with Leo, you could interfere with reception at the repeater.

 

Ok, so as I understand it, transmitting in simplex from the KG1000 on channels 1-7 and 15-22 (462.xxx MHz) should be ok. 8-14 (467.xxx MHz) blocked on KG1000 due to output wattage anyhow. 

However, if I'm using the KG1000 in duplex (467.xxx MHz) on other repeaters it could cause deafening of my own repeater, especially around my repeaters input frequency as it is not a high-end duplexer. Good food for thought. Radio traffic is always light in my area anyhow, so I don't see it as an issue, but this good knowledge to have. Thank you, guys, for your input. I appreciate it. I guess one last question I have is, if I upgraded the duplexer to a higher quality can type, would I still have the same issues with deafening of my repeater due to the proximity of the two antennas?

[LeoG]

Closer the antennas are to each other, the more possibility they might interfere.  When you have a repeater without a duplexer the antennas are usually put at different heights along with keeping the space between them as much as possible.  The height part makes a big difference.