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[LZ3NUK]

Hello guys,
I am a recently new, self-taught radio enthusiast.
For a while i have been trying to create a private line (PL) connection over the existing public frequency with CTCSS, DCS and DTCS codes on my radio so i can have a private channel for me and my friends without any outside interference. We are all using the dual-band Baofeng UV-6r and so far we have succeeded to not receive outside messages, but we can still be heard from a radio user that is on the same public frequency.
So is there any way to create that fully private line over the public frequencies, of is it just a far fetched dream of ours.
Thanks in advance to everyone

[K4GTE]

No encryption and no one owns a frequency in the amateur radio bands. FCC rules in the US. I'm pretty sure that's also international rules.

[DL9BDM]

There is a need for clarification here: What do you mean by "public frequencies"? What kind of people are your friends? It is not the purpose of ham radio to replace the telephone. Contact on amateur frequencies is to be conducted among licensed radio amateurs (and only them) in open speech. Unlicensed people have no business there.

If you set up a non-public network of unlicensed people on amateur radio frequencies, you are in violation of your license requirements.

[W9IQ]

CTCSS, DCS and DTCS are various schemes that allow your squelch to be opened by their presence in a signal. But if anyone manually opens their squelch or they set their squelch to open on the same CTCSS, DCS or DTCS signal, they could easily listen to your conversation.

If you are after privacy against eavesdropping, then you need to incorporate encryption/scrambling. In the US, many regulated radio services are allowed to encrypt their signals but the amateur radio service in the US is not allowed to do so.

If you are looking to encrypt your transmissions, make certain to check and comply with your local regulations.

- Glenn W9IQ

[W1VT]

Yes, you need some form of encryption or scrambling to obscure your signals.  But, even that won't totally hide your signals.  The location of the transmitters can still be found. 
Some information, such as how often and when the transmissions occur,  can still be recorded by someone willing to put in the effort.

[LZ3NUK]

Just to clary some things i left out.

Me and my friends all have a European radio amateur license class 2 and we are looking into if PL over the public frequencies (430-440 MHz on which license-free radios are permitted to operate) is possible and legal.

We are not trying to take over a whole frequency of the amateur radio band.

The thing is that we are trying to achieve a connection in which we do not get disturbed and we do not disturb other radio users. We do not want a complete privacy since we know that is pretty hard to accomplish plus we are not bothered by anybody knowing the time of transmission, or recording.
The main purpose is so that we can create a PL for an airsoft game that wont be heard by the opposing team.

Thank you to everyone for your responses!

[K4PIH]

Grow up.

[WA2EIO]

W9IQ summed it up perfectly.   
PL means that the signal will not be heard by others not using the same PL frequency, as you have found already, but the transmission itself is in the clear, and can be received by anyone. 

The original use of PL was to allow many users to use one frequency, but for the radio to remain quiet (squelched) until it detected the correct PL tone.   That way no one would have to listen to endless communications that were not related to their particular business.  Actually, radios had a "monitor" button which was supposed to be held in before transmitting, in order for the user  to check to be sure that the frequency was not already in use before they actuated their transmission.

 I do not think you can achieve your goals with amateur radios on amateur frequencies.

[W0CKI]

Just children with cheap ham toys.
Gary W0CKI

[KF6QEX]

"The main purpose is so that we can create a PL for an airsoft game that wont be heard by the opposing team."

Cellphones with Push-to-talk feature  or a conference call at the beginning of the game, or a few of these https://www.amazon.com/gp/product/B012J1CLFE/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B012J1CLFE&linkCode=as2&tag=hotogeajoonan-20&linkId=d956bef67eeab8c4374686706301df3b

 

[KF6QEX]

Just children with cheap ham toys.
Gary W0CKI

Even expensive ham toys wouldn't do the trick legally.

[WA3SKN]

I cannot speak for "LZ" rules.
However, under FCC rules we are allowed to have a "closed repeater".  That does not preclude other amateurs from using those frequencies. (or attempting to).
Encryption, codes, and cyphers are not allowed except for satellite "command and control" functions.

-Mike.

[LZ3NUK]

Thanks to everyone for the useful and helpful advices 😄 and of course the “grumpy gramps” ones too.😉

[KE6VG]

Search for encrypted handheld radio on youtube. You can order them on Aliexpress. They are non licensed FRS radios. Yes it's illegal to encrypt in lots of countries.

[WB6BYU]

Summary:

Anything you transmit can be heard by anyone listening on
the frequency.  Unless it is encrypted, anyone can understand
what you are saying if they have a receiver for that mode.

What CTCSS or DCS does is to enable the user not to hear
other stations on the frequency until the proper signal is
received.  If everybody has it enabled, then users don't hear
other transmissions.  But transmissions can still interfere
with each other - that's why most systems have some way
to check that the frequency is clear.  (With some radios,
the receive tone squelch is disabled when the microphone
is picked up out of the holder, so you can hear if the
frequency is already in use before you transmit.)

So those systems allow the user not to hear other stations,
but don't prevent other stations from hearing your transmissions.