Questions and Answers 

1) Radtel RT-4D

1. Q: 

   RT-4D device cannot connect to hotspot (but repeater works fine), how to solve it?
   Description:
   User encountered the following problems when setting up RT-4D:

   1. The device cannot activate hotspot and cannot connect to Brandmeister network, but repeater works fine.

   2. The latest firmware, DMR chip and CPS software have been updated, and the hotspot and other devices are confirmed to be normal.

   3. Other users have also reported similar problems (RT-4D compatibility issues with hotspots).
   A:Solve problems with precise frequency calibration
   

   Cause Analysis:
   The connection problem between the device and the hotspot may be caused by frequency offset. Even a small deviation (such as ±0.2 kHz) may prevent the device from syncing with the hotspot.

   Solution steps:

   Get the debugging tool:

   1.If you have a frequency detection instrument (such as a professional SDR or frequency meter), contact technical support to obtain the debugging software.
   Accurately calibrate the frequency:

   2.Open the debugging software and adjust the frequency offset value as instructed to ensure that the error is within ±0.2 kHz.
   Focus on checking whether the transmit/receive frequency of the device and the hotspot are exactly the same.
   Complete debugging and restart:

   3.Click "Finish" in the lower left corner of the software interface to save the settings.
   Power off and restart RT-4D to apply the new configuration.
   Verify the connection:

   4.Try to connect to the hotspot again to confirm whether it is successfully connected to the network.

   2. Q：I tried to update the firmware, but, when the tool showed the "finished", the radio restarted and it's now stuck on the RADTEL boot screen. What can I do?
       A:There are several solutions. One is to remove the battery, put it aside and wait for a few minutes before reinstalling it and turning it on. Another is to turn it on with the menu key. Try it several times. If it doesn't work, then re-upgrade the digital firmware.
   3.Q:I recently bought a 4D and updated it but now it only shows a green light, no audio or display. I have tried flashing the firmware and the DMR chip but that didn't work - I have also tried the reset method - can you help?
   
   A:This is data loss. If you have flashed the latest firmware, you can press and hold the 0 key to start the machine, and then wait for a few seconds, the machine will automatically restore the data.
   

2)Radtel RT-880

1.Q:Why do I need a password to download the cps and firmware of Radtel rt 880?
A:We currently only provide firmware and CPS software to consumers who have purchased our Radtel RT-880, so please contact me via WhatsApp and email and send me your order screenshot or order number directly. We will provide you with the password after verification.
2.Q:How to enter the CB band?
A:If it is a two-way radio, Basic Settings->17 Work Range->18-64MHz, after confirmation, the machine will automatically restart and you can enter directly. If you listen to 2-30MHz broadcast radio, or shortwave LSB USB CW signal, you need to enter the radio mode, long press the # key to switch the frequency band, and short press the # key to switch the mode.
If you think this operation is too troublesome, you can consider holding down the ▼ key to turn on the machine and turn on the full-band debugging mode. At this time, you don’t need to enter the menu to switch the frequency band, you can directly enter the CB band frequency, but remember to replace the antenna, otherwise the transmission may cause damage.
3.Q:Have a question about squelch. Even at the lowest setting (1), the squelch does not open even when the signal is strong (S +10). There is noise at S6.
When I open the squelch manually with the side button, the signal can be heard. I tested it several times on the 2 meter band 144.500 MHz.
Any suggestions?
A:Analog Settings->Glitch TH setting, adjust it higher, it may be set to 0
4.Q:I have a new RT-880 that seems to have a SW mode defect. I loaded firmware v1.06A20250417. There are loud clicking noises faster than 1/second. This happens with or without a SW antenna, at home or away, in AM, USB, and LSB, and on all the frequencies I've tested. Is there any setting to check, or is this unit defective?

A:Analog Set->RSSI Refresh value should be increased

3)Radtel RT-860
1.Q: I have a Radtel860, and there is no option 5 on its menu. There are only 4 options for Sistem Time, which is what the manual says. I use version 1.6. I saw a video of Radtel860 on YouTube, which had a Site Time option, but mine does not have it.
A: Option 5 is the system time, but it was later cancelled because customers complained that the time could not be saved. This is because the hardware does not support saving time.
2.Q: My 860 started flashing orange and blue when charging. Does anyone know what this could be? Now I am not getting any charging indication at all. Tried multiple chargers. It acts like it is running low on supply. Tried different batteries in the radio, same result, no charging.
A: The flashing orange and blue light is the reason for no battery being detected, in this case, it could be an open circuit or a bad battery.