The other day I ran into an issue with my Baofeng UV-5R. It stopped transmitting.
I turned to the internet and scoured message boards and websites to understand this problem. After some research I was able to understand what was going on and find a solution.
This led me to write a post with my research findings.
This article has been organized to present some basic checks first. After that it gets into problems with transmission and solutions.
The solutions presented in this article apply to the following Baofeng radios:
- 1 Basic UV-5R Troubleshooting
- 2 How to Transmit
- 3 UV-5R Transmission Problems and Solutions
- 4 Frequently Asked Questions
- 5 Summary
Basic UV-5R Troubleshooting
Check the Battery
As a basic check, make sure that the battery is fully charged.
Note that the radio is normally shipped from the factory with a battery that is completely discharged. Use the charger – either provided or specified by the manufacturer.
The charge time for the UV-5R is 4-5 hours. Once charged, the LED should turn a solid green color.
If the radio still doesn’t transmit, try removing the battery completely and reinstalling it.
A basic check is to ensure that the antenna has been installed correctly.
Install as shown in the picture above. Turn the antenna clockwise until it stops rotating. Never rotate the radio to install the antenna. That will damage the connector and prevent radio from transmitting or receiving signals.
Also never transmit signals without an antenna. Doing so will damage the electronics inside the radio permanently.
To understand this better, consider that when an antenna is not connected, all the input power is reflected back. This can damage the transmit power amplifier. When 100% of the input power is reflected, this calculator can be used to find the reflection coefficient Γ = 1 and the VSWR = ∞. The ideal value of VSWR is 1 and a good value is 1.5. Without an antenna, we’re infinitely far from ideal!
How to Transmit
The Push-to-talk (PTT) key is pressed for transmission and released for reception. The key is number 7 in the picture below.
UV-5R Transmission Problems and Solutions
Here is a list of specific problems and solutions
Other members of the group cannot hear you
- Make sure the undertones CTCSS and or code DCS programmed into your transceiver is the same as those programmed into the radios of other members of your group
- The distance between your radio and others could be too large. The range of the Baofeng can be 10 miles but that’s only when there are no obstructions or radio interference. In a city there’s seldom a line-of-sight path between the transmitter and receiver. As well there are many interfering signals. As a result, the range can be only a mile or even less. (Use this calculator to find the maximum range of a two way radio)
UV-5R can receive but not transmit
If your radio can receive, we know that there’s no issue with the battery and antenna or programming. Does the UV-5R UV-5R beep when trying to transmit on certain frequencies? If the answer is yes, that means that the frequencies you are trying to operate on are locked in firmware. This is why you are unable to transmit. Let’s understand why.
While the UV-5R can transmit across many frequency bands, newer versions of the radio sold can only work in select bands. Furthermore these working bands depend on your geographic region. In the USA for instance, this has been done so that users comply with the FCC rules. Spectrum regulators in other country as well require that radios transmit only in designated bands.
UV-5R’s sold in the USA and Canada for instance, will only transmit on frequencies in the range of 144 – 148 MHz and 420 – 450 MHz. These are the amateur radio bands. These specific frequency ranges are also called 2 m and 70 cm bands (the equivalent wavelength).
The radio will only receive in other bands. The UV-5R covers three frequency bands:
- 65 – 108 MHz
- 136 – 174 MHz
- 400 – 520 MHz
In the USA you will be able to listen to the FM band 88-108 MHz. But you will not be allowed to transmit in the FM band. The band over which the radio receives is wider than that over which it is able to transmit.
Below is a table that shows the frequencies of the UV-5R in different countries:
|UK||136-174 MHz |
Note that if you live in the USA and bought your Baofeng radio in the UK, you will have a wider frequency range for transmission. However operating outside of the two ranges 144-148 MHz and 420-450 MHz in the USA is not legal.
There’s another variant of the radio called the UV-5R Tri-band. This radio is able to operate in three frequency ranges.
- 136 – 174 MHz
- 220 – 225 MHz
- 400 – 520 MHz
However, as with the UV-5R the legal operating bands are restricted depending on geography. Note that in addition to the 144-148 MHz and 420-450 MHz bands the other allowable band for amateur radio in the USA is 222-225 MHz. Canada also allows 219–220 MHz.
Due to limitations on its frequency range, Baofeng cannot communicate with radio products that operate in other frequency bands like CB Radio for instance.
The receiver in a Baofeng radio is not built like a receiver in test equipment. It can get desensitized (or desensed) very easily. When this happens to a receiver, it might lead you to conclude that the transmitter is not working.
This means that if two radios are too close to each other or if there’s a strong interfering signal nearby it can overload the receiver. In that case you might think that your radio is not transmitting but in actual fact it is. The issue is that the other radio trying to listen but cannot as there is too much signal going into it.
The solution in this case is to separate the two radios. In the case of an interfering signal – it will have to be found and removed or shut down.
Frequently Asked Questions
What is the frequency range of the Baofeng UV-5R?
- The Transmit frequency range of the UV-5R is 136-174 MHz and 400-520 MHz.
- The Receive frequency range of the UV-5R is 68-108 MHz, 136 – 174 MHz and 400 – 520 MHz
In this post we have discussed the problem of UV-5R not transmitting. Various problem scenarios are covered and solutions for each have been provided. To summarize here are the main transmission problems that can be solved:
- Other members of the group cannot hear you
- UV-5R can receive but not transmit
- Radio Desense