PL Codes/Tones/DCS Repeater use vs Simplex use

[Webslinger]

So, question(s) on the use of PL tones when programming repeaters vs. using them for simplex communication between two GMRS operators/HT's. I have the mechanics down for programming tones when programming local repeaters. It's the theory I'm struggling with somewhat. If I understand this correctly, using a PL tone when I transmit to a repeater opens the repeater to receive the transmission. The repeater then retransmits my transmission out to a greater distance than my radio is capable of doing on its own. Now, is that retransmission heard by 100% of the operators monitoring that repeater frequency and within range, or is it only heard by those operators that have also programmed in the PL tone on the receive side that matches the PL tone I programmed in on the transmit side? (geez) Also, can the transmit PL tone be different than the receive PL tone, or do they always have to be the same, say for example when participating in a GMRS social net being conducted through a repeater? 

Now, when communicating on a simplex channel, can you use these same PL tones to set up "private" communication between two operators/radios? I understand that "private" is not really private in that anyone monitoring the same simplex channel will hear everything you say, but by using PL tones, it reduces the chance that others who are listening in from having the ability to break in on your conversation, right? 

So, in the case of simplex communications, is the transmit PL tone doing the same thing to the receiving radio that it does for a receiving repeater - opening it up (breaking squelch? Not sure if that's the right term for this)?

Thanks!

 

[hfd376]

37 minutes ago, Webslinger said:

In a receiver, the PL tone is a filter to keep other radios out that have no PL tone, or a different tone from accessing the receiver. Whether its a repeater, mobile or handheld receiver. If anyone is monitoring the frequency with a different PL tone, they won't hear the transmissions of repeaters or other radios.  If they have no PL tone programmed, they'll all traffic on the frequency. Also, if you and your friend go to an event and want to keep in touch but not hear other users on the frequency, program a PL tone on the transmit and receive in your radios. Transmit PL tones have match the receiver's PL tone to access the receiver.

 

 

[quarterwave]

A transmission on a frequency can be heard by a radio receiving on the same frequency if it is within range. Squelch tones/codes do not change that, they only filter out anything that does not match your code. If running no code/tone on receive, you hear it all.  You can use different in and out tones/codes on a repeater, but it's not necessary, it is usually only done to to mask the input by using a different output. The radio won't know as long as it's programmed properly, but its not ideal for easy operation. Usually a repeater trying to stay inaccessible but only to a private group does this. 

Simplex - run same codes all around, or none at all if you want to hear everyone (else). 

Private is not that. The term was used with the intention of reducing audio traffic on a groups radios when said group shared a frequency or repeater with others....back when there may not have been so many to share (part 90). Don't confuse that with scrambling or encryption. 

[WRXB215]

Think of tones as "I don't want to hear others" rather than "I don't want other to hear me."

[WRPG745]

1 hour ago, Webslinger said:

So, in the case of simplex communications, is the transmit PL tone doing the same thing to the receiving radio that it does for a receiving repeater - opening it up (breaking squelch? Not sure if that's the right term for this)?

Everything said before answers the question, but just to simplify, think of it this way:

The repeater uses the tone to ignore any transmission NOT using the tone. (only hears transmissions with the tone).

You use the tone the same way, to NOT hear others NOT using the tone.

If you transmit with a tone, anyone listening with the tone hears you, AND anyone with no tone will also hear you, but "breaking squelch" is about signal strength (with or without a tone).