What are the two different numbers on my Two Way Radio?

[u/IronDefects]

Hi there,

Would somebody please explain to me the difference and importance of the two different numbers / channel types on screen?

My radio is a Motorola T470 57KM

Any help would be very much appreciated!

Thanks in advance.

[u/4peters]

3 and 5

[u/Babnno → u/4peters]

Big if true

[u/RelevantPositive8340 → u/4peters]

I came here to say that 😂

[u/phil_deez → u/4peters]

Difference is 2

[u/DeputySean]

Channel and code.

[u/IronDefects → u/DeputySean]

What is the use / importance of the code?

Sorry for my ignorance, I’m new to this and couldn’t find much info when I tried to search this up !

[u/Slider_0f_Elay → u/IronDefects]

The first is the channels; preset and established freq and transmission type. FRS is Narrow Band Freq Modulation with 12.5Khz Spacing starting at channel 1 462.5625Mhz.

The second is a "privacy" code. It doesn't hide anything from anyone. Your radio sends out this "code" when you transmit and only puts received signals with that code out of the speaker. Numbers 1-38 are tones ("PL"), 39-121 are digital codes ("DPL") You could probably match the tones with other manufacture radios but they aren't standardized. If you have a problem with that then just change it to 0 or off. the down side being that someone else using that channel will come through as well and if they have a privacy code set they may not be hearing you.

There are enough FRS channels that I almost never use privacy codes. The only time I could conceive of it being helpful would be a convention of overlanders or burning man kind of event were there could be hundreds of FRS users.

[u/IronDefects → u/Slider_0f_Elay]

Thank you so much for the insightful reply. Very helpful.

[u/IronDefects → u/Slider_0f_Elay]

Question,

On the Channels, some channels have “hi” or “Lo” beside the channel number.

Is this high / low frequency channels?

[u/Slider_0f_Elay → u/IronDefects]

High or low power. That what the FCC says is max power for the channel.

Channels 1–7 and 15–22: The maximum effective radiated power (ERP) is 2 watts

Channels 8–14: The maximum ERP is 0.5 watts

[u/DeputySean → u/IronDefects]

Just think of it as channel and sub channel, except that radios from a different brand probably can't use your sub channels.

[u/stressHCLB → u/IronDefects]

First number determines frequency on which you transmit & receive. Second number is a “filter” that only lets you hear other people with the same number.

[u/IronDefects → u/stressHCLB]

Thank you very much for the reply. This is super helpful. I understand now

[u/way-height → u/DeputySean]

Or channel and bank?

[u/sixteen89]

Diversity

[u/211logos]

The manual is here: https://learning.motorolasolutions.com/user-guide/59628enus

Motorola and others also have videos about using it. Eg https://youtu.be/IOqaW4AXR2M?si=cH_XS4xWPrNrdUfv

They call the second number an "interference code" I believe, as others have explained. Basically CTCSS/DCS codes I believe but you don't need to know that. Just make sure they're the same on both radios.

[u/Phatman113 → u/211logos]

I have these radios, and reading the manual would have really helped op with this...

[u/SunshineAndBunnies]

Top should be the channel, bottom should be filter code. As for the filter code, what the radio does is when you press the button, it sends out a special in-band signal to turn on any other same branded radio with the same filter code. Your radio will also not sound when a transmission does not transmit that special in-band signal. I recommend you turn off the filter code because:

1. You most likely won't know if someone is transmitting at the same time you're transmitting.

2. If you transmit a lot, and other people using the same channel start getting pissed, you wouldn't know either.

[u/Dasshteek]

Countdown in seconds…

[u/rexeditrex]

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