Fire VHF Direct Mode

[brendan3]

Question for the brain trust regarding direct mode on squelch protected repeater sites. Using cal fire for example the repeaters often require an input tone. However there are times when this is bypassed by going to direct mode.

What occurs when direct mode is used?

 

[DMS11B]

What do you mean what occurs?

In direct mode the radio operator transmitts on the output frequency of the repeated channel, typically at low power 5watts-ish which is received on any receiver that is within reception on that particular frequency and tone.

 

[brendan3]

Taking cal fire as an example most of the radios are setup to receive a specific frequency and tone. So when a user enters simplex mode, how is that the other radios still receive the transmission?

 

[wtp]

because they are using the same frequency and tone.

 

[f40ph]

The radios (in direct mode) transmit the PL tone that is normally used for rx protection along with the repeater output freq.

 

[brendan3]

And the repeater will still receive the transmission? If so, what is the point of having tones and this direct mode?

 

[f40ph]

And the repeater will still receive the transmission?

Nope. Pressing direct mode is like saying "I don't need the repeater, I'm transmitting as-if I'm the repeater"

If so, what is the point of having tones and this direct mode?

If a radio is programmed as "tone protected" on a repeater channel, you wouldn't hear anyone transmitting right next to you unless their radio acts like the repeater. The direct radio MUST transmit the PL tone in order to break through everyone's squelch listening on the channel locally.

 

[mmckenna]

And the repeater will still receive the transmission? If so, what is the point of having tones and this direct mode?

Direct mode transmits on the repeater OUTPUT frequency. NOT the repeater input frequency. The repeater never hears it.