Baofeng UV-5R Minimum Transmit Time after PTT

Greetings all,

I am doing some experimenting with keying the UV-5R via PTT input and am not able to get a transmission time less than the default 450 msec. I’ve tried several menu settings, but none seem to shorten the xmit time.

Anyone have any experience with setting the minimum PTT duration?


I’m a little confused on a couple of things here. First, unless Baofeng has changed the Timeout Timer on the UV-5R recently, the timeout range is 15-600 seconds. I have never heard of a UV-5R with the ability to timeout transmit in less than 1 second. I am certainly unaware of one with a setting of 450 milliseconds.

Of course, my UV-5R is old, and I don’t use it anymore as I’ve since replaced it with other radios, so it’s possible I’m completely behind the times on it. But that brings me to the second question.

Why would anyone want a transmit time of less than half a second?

Also, the Timeout Timer sets the maximum transmit time, not the minimum. The only minimum transmit time that I know of is determined by how long you press the PTT before releasing it.

The default timeout on my version of the UV-5R is 60 seconds, btw, so maybe my radio really is old.

Hi Rick,

I’m not referring to the transmit timeout (TOT). I am trying to reduce the minimum transmit time that occurs when the PTT is activated. This has to do with my experimenting with digital transmission where the transmitter is on for very short bursts.

I’m not sure that’s doable with the UV-5R. It was designed for standard analog voice transmissions, not short bursts. That’s not to say it isn’t hackable, but the radio wasn’t specifically made for what you are trying to do, so there is no menu setting that I know of that will allow you to reduce the minimum transmit time.

I understand that the UV-5R is not intended for digital communication. It was just an experiment that I tried. I may look into buying the DVR version.

The other issue is that the transmit also ramps up to full power. It’s very quick, but a few people complained when they first came out and were trying to use packet - the ramp up missed the first bit of the data stream. Not sure if this is important for your idea?

Most digital operation on the Baofengs occurs with the VOX activated. This causes problems, as the transmitter is left keyed for a certain amount of time after the transmission ends. The transmitter remains keyed for over half a second and therefore, the application using the Baofeng as its transceiver could miss any replies. For this reason, it’s not recommended to use the radio on VOX; but rather use some sort of keying circuit.