Baofeng UV-B5 DCS / CTCSS question

Hello all,

It’s my first radio and my first post so please excuse the newbie errors and don’t hesitate to explain de magic acronyms which everyone uses here and which are complete martian to me :slight_smile:

I bought 4 UV-B5 to use in motorsports with the following requirements.

Radio 1 will be in car 1
Radio 2 will be in car 2
Radio 3 will be in the pits
Radio 4 will be in the pits

Now here is what I want to be able to achieve with 2 frequencies and the help of DCS or CTCSS…

Radio 1 can talk anytime to radios 3 and 4 but not to 2 so that 1 driver does not disturb the other one.
Radio 2 can talk anytime to 3 and 4 but not to 1
Radio 3 and 4 can talk anytime together without 1 and 2 listening to what they say.
Radio 3 and 4 can talk to 1 or 2 using a special frequencey or DCS combination

So far I have thought that I would use frequency A for radio 1, frequency B for radio 2, have them use a DCS and have radios 3 and 4 on both frequencies A and B without DCS to speak between themsleves (3 and 4) and activate the DCS when they want to speak to 1 or 2 (having selected the proper frequency of course)

But I did not find in the UV-B5 a quick way (push of a button) to enable or disable the DCS, so I can listen to both frequencies A and B on radio 3 and 4 without any problem but when they speak together it also gets in 1 and 2 which I don’t wan’t because the drivers are supposed to drive and not be disturbed by pitwall conversations…

Is there a way to do what I want easily ?

Thanks a lot for the help

OK, I’ve tried to come up with some sort of method to do this and I’ve got a solution but its not a perfect one…

There is one question, would it be acceptable to have Radio 3/4 assigned to one car? (Ex: Radio 3 is assigned to Car 1 by default, and Radio 4 is assigned to Car 2)

So for this example: I am going to use 154.6000 (MURS) and as you suggested use the DCS/CTCSS to remove one conversation from another.

Radio 1
TX: 154.6000 / 100.0 (Frequency / CTCSS Tone)
RX: 154.6000 / 100.0

Radio 2
TX: 154.6000 / 233.6
RX: 154.6000 / 233.6

Radio 3
TX: 154.6000 / 100.0
RX: 154.6000 / No Tone

Radio 4
TX: 154.6000 / 233.6
RX: 154.6000 / No Tone

Here Radio 1 can transmit to Radio 3 & 4, but only Radio 3 can talk to Radio 1

Radio 2 can transmit to Radio 3 & 4, but only Radio 4 can talk to Radio 2

Radio 3 and 4 can talk to one another without issue.

If you required Radio 3 to talk to Radio 2, and Radio 4 to Radio 1 then you can program a second channel to use the opposite of the the other radio so Radio 3 programming on Channel space 1 and Radio 4 programming on Channel space 2. Then the opposite on the other radio.

Does this make sense?

Hello and thanks for the reply.

In your idea would radio 3 be able to hear BOTH cars (1 and 2) while being able to talk only to 1 for example ?

I was thinking to do as follows, tell me where I’m wrong because i’m proably wrong

Since the UV-B5 has standby on 2 frequencies I was thinking of using 1 freq for 1 car and the other for the other car and the DCS thing to prevent the cars from hearing the pits…

so it would be something like this

Radio 1 : TX and RX 154.600, DCS 100
Radio 2 : TX and RX 147.500, DCS 100
Radio 3 TX 154.600 and 147.500, RX 154.600 and 147.500 DCS 100 ONLY when talking to the car and off to talk to radio 4
Radio 4 TX 154.600 and 147.500, RX 154.600 and 147.500 DCS 100 ONLY when talking to the car and off to talk to radio 3

My problem at the moment is no find a way to trigger EASILY (meaning not going into the menus) the DCS to be able to talk on whichever channel without DCS from radio 3 to 4 and 4 to 3 and then to switch the DCS on to be able to talk to radio 1 or 2…

If it’s not possible then I can go your route but it will be a problem for me (radio 3) not to be able to talk to both cars…worst case scenario I will have 2 radios with me…

What do you think ?


Yes, Radio 3 and 4 would be able to hear traffic from every other radio. So 3 and 4 can hear one another and traffic from both.

The only concern here would be I don’t believe the radios can transmit on two frequencies at the same time. I may be mistaken as I have not read the users manual but I believe it may only be able to watch another frequency (ex: RX only).

The easiest way to solve the issue would be to set your radio (Radio 3) to have Radio 3 programming on Channel space 1 and Radio 4 programming on Channel space 2. So that way would would always hear traffic from everyone no matter what channel you’re on but simply selecting channel 1 or 2 would give you access to Radio 1 or Radio 2 depending one what channel you have selected. That may be the simplest way to go about it, as the channel selector is a simple flick to change rather than entering the menu each time you want to change.

Just as a side note: I’d rather have to switch channels on my radio rather than carry two (done that, no fun there)

Yep, they can RX at the same time on 2 channels (well they just do frequency hopping every 500ms) but not TX.

I don’t mind switching the channel using the rotating pot to talk to this or that car and as long as I can talk to both cars (with the switch) and to the mechanic (radio 4) it’s perfect for me.

But i’m still stuck on how to activate the DCS only when i want to talk to the cars so that they hear me and not when I talk to the mechanic only and I don’t want to disturb the drivers…

I would need to be able to use one of the lower PTT buttons to (de)activate DCS…

I will play with the radios and the settings you sent me and report, thanks for the ideas…

That makes sense! If you don’t mind switching channels, I would try out the programming I first suggested and have Radio 3 and Radio 4 programmed as listed on the first Channel space, then switch the programming for the second channel spacing and that should allow you to talk to the two cars (one per channel) while still being able to hear everything that is said.

Here’s a quick explanation of why that works. The two pit radios are set to receive with no PL tone meaning they will hear everything that is said on that frequency even if it is sent using a CTCSS tone. So having no tone set allows it to get everything but adding a tone to the RX side will limit what it can hear (hence why the drivers radios have a tone set on the RX side). So because Radio 3 has a tone matching the RX side of Radio 1 then 3 and 1 can talk to one another but because there is no tone on the RX side of Radio 3 it will also catch message sent from Radio 2. You can think of the tones in this case as a filter, basically as you transmit it across the frequency the tone filters out unwanted transmissions unless they have a matching filter. So no tone means no filter and you can get everything!

Hope this helps, and let us know how (if) it works out!

Ok, got it, and the good news i that it works for an infinite number of radios :slight_smile:

radio 1 (car 1) freq A : DCS RX A
radio 2 (car 2) freq A : DCS RX B

radio 3 and 4 (pit 1 and 2) have 3 channels

channel 1 to talk to radio 1 : freq A DCS TX A
channel 2 to talk to radio 2 : freq A DCS TX B
channel 3 to talk to radio 4 : freq A no DCS

the car radios never switch channels, they have only 1 and stay like that

the pit radios (3 and 4) are usually always on 3 to speak between themselves without interfering with the drivers, when a driver calls they can hear it and switch to the relevant channel (1 for car 1 and 2 for car 2) to reply.

Tested and it works…

the beauty is that we can add as many cars (or bikes or whatever) as we can add channels…

Thanks for the tips