Successful Tests with Egzumer Firmware for the Quansheng UV-K5 TX (Part 3)

Introduction

The QUANSHENG UV-K5 is a dual-band VHF – UHF transceiver. Its internal firmware can be easily updated to improve its functionality. Various firmware sources are available online for download to the UV-K5. After several trials, the most advanced version appears to be the one provided by EGZUMER.

Firmware Modification

The QUANSHENG UV-K5 is an open TX, easily reconfigurable. Several sources provide different versions of the internal software, allowing for the addition of functions or modification of its operation. After testing several of these internal software versions, the one that seems to offer the most interest is Egzumer's. We specifically tested version v0.21, which was released on December 19, 2023.

Photo 1: The QUANSHENG UV-K5 TX with the EGZUMER firmware version. The mention 'EGZUMER v0.21' is visible at the bottom of the home screen.

Improvements and Previous Versions

The main weakness of previous versions was AM demodulation; the Egzumer version corrects this and provides very good AM quality. It even allows for BLU (USB) demodulation. The frequency step can be adjusted to within 10 Hz, which is very useful for BLU.

Previously, the initial manufacturer firmware was modified using a version found on the site https://whosmatt.github.io/uvmod/. This version is referred to as the "anterior" version in this article, and its results are significantly better when compared to the Egzumer version.

Firmware Reprogramming Procedure

It's important to know that if frequencies are already programmed into the UV-K5 TX before firmware modification, they will be preserved. This data is stored in a different part of the internal memory.

Procedure to follow:

1. Connect everything: the PC, the programming cable, and the UV-K5.
2. Start by running the CP210x_USB.exe program to enable communication via USB port.
3. Set the TX to firmware modification configuration by pressing [ON] with [PTT] held down.
4. Download the new firmware from: https://egzumer.github.io/uvtools/?firmwareURL=https://github.com/egzumer/uv-k5-firmware-custom/releases/download/v0.21/egzumer_v0.21.packed.bin

For this programming, Chrome had to be used because the transfer did not work with Firefox on our PC.

Comparison with Previous Versions

With two UV-K5 units, comparing the Egzumer version and the anterior version is straightforward for apparent functions. However, the number of functions to test is vast, making an exhaustive comparison difficult.

Upon startup, the home screen displays "EGZUMER v0.21" at the bottom (Photo 1). The voice prompts, such as "Welcome / Channel Mode 21," have disappeared, which is not a negative point.

The 51 menus of the initial version have increased to 60. There are even 69 menus with some hidden menus. These hidden menus can be accessed by pressing [ON] with [PTT] + [PF1] held down. They allow, for example, setting emission ranges, limiting emissions to amateur radio bands, performing a partial or total TX reset, or calibrating the battery discharge curve.

Usage of the Egzumer Version

AM tests show a very notable improvement in reception quality. This is a significant positive point for this version.

The S-meter of the anterior version was very generous and saturated quickly. The S-meter of the new version appears more spread out. Further investigation would be needed to convert these impressions into precise figures.

In the previous version, two consecutive key presses were required to access the secondary function marked on the key. Now, a short press corresponds to the primary function, and a long press to the secondary. For example, for the [3 - VFO/MR] key, a short press gives "3," and a long press allows switching between VFO and memories. This is very practical.

In reception, the Quansheng covers the entire band from 18.000 MHz (Photo 2) to 1300 MHz (Photo 3), with a gap between 630 MHz and 840 MHz (limitation of the Beken BK4819). It should be noted that sensitivity is quite reduced in this upper band. It was measured at -115 dBm at 800 MHz and only -75 dBm at 1300 MHz, whereas it is -127 dBm in VHF RA and -124 dBm in UHF RA. In transmission, it works very well on amateur radio bands. Regarding transmission on HF bands, for example at 27 MHz, do not trust certain messages found online: it does not work. The transmitted power in HF is so reduced that the range is insignificant, and spurious emissions are very important.

Photo 2: Reception frequency starts at 18 MHz.

Photo 3: UV-K5 screen displaying reception of frequency 1298.500 MHz.

Spectrum Analyzer

The new version includes a spectrum analyzer. It is accessed via [F], [5]. Exit is via [Exit]. Its operation is described on the page: https://github.com/egzumer/uv-k5-firmware-custom/wiki/Spectrum-analyzer.

As the internal software space is physically limited, these additional functions were added by removing some others. The Aircopy function, for example, was removed, as was access to NOAA memories. These functions had limited interest.

The 1750 Hz tone, very useful for opening relays, was not immediately found. It was previously on the [PF1] key with a long press. This function still exists: to send the 1750 Hz tone, you must now transmit using [PTT] and press [PF2] while transmitting. This is quite logical and works very well.

Power Test

In previous tests, it was noted that the H – M – L (High, Medium, Low) power levels did not have a sufficiently large spread. The measurement with the new firmware version yielded "3.8W – 2.8W – 2.4W" in VHF and "4.2W – 3.2W – 2.7W" in UHF. This point has not been corrected in the standard version that was loaded. There is a variant called "Egzumer QRP" (Armel) which reportedly provides 100 mW in Low, but it has not yet been tested.

Synthesis and Perspectives

Given its very modest cost, the Quansheng UV-K5 TX is an excellent deal, and its internal software can be improved. The new firmware version, developed by EGZUMER, contains very notable improvements compared to previous and competing versions. It is truly worth reprogramming the firmware with this version. This reprogramming is relatively easy to do.

At the time of writing this article, a new version had been released, "Egzumer v0.22," with some minor corrections in the firmware.

To conclude, a question that regularly arises: can 406 MHz distress beacons be decoded with a UV-K5? It is impossible to extract the "discri" signal. Only the BF (audio) can be used. Our FM demodulation tests were negative, with the BF containing a fundamental at 400 Hz at too high a level. However, we managed to demodulate the signal of a genuine 406 MHz beacon by changing the demodulation type, i.e., by switching to AM reception. Investigations are ongoing.

Appendix I: Menus of Egzumer Version V.0.21 (in English)

Source: https://github.com/egzumer/uv-k5-firmware-custom/wiki/Menu

Menu Operation

The menu can be accessed with the [M] button (short press). Once in the main menu, menu items are displayed on the left side of the screen. The currently selected menu item is highlighted, and its current value is shown on the right. At the bottom left, the menu item number is displayed, ranging from 01 to the highest number. To find a menu item, use the UP/DOWN arrow keys or enter the menu item number on the numeric keypad. For example, to access VOX settings, enter number 57. Once the desired menu item is highlighted, pressing the Menu key enters that item. After selecting a menu item, use the up and down arrow keys to adjust the setting. Press the Menu key to confirm, or the EXIT key to cancel.

Main Menu Items

The number preceding the menu item description is a menu item number for quick selection.

• 1. Step - Frequency step (in kHz). UP/DOWN buttons change frequency by this value. Frequency must be a multiple of half this value.
• 2. TxPwr - Radio output power (LOW/MID/HIGH).
• 3. RXDCS - Receiver Digital-Coded Squelch. Squelch unlocks only if the specified code is received. A DCS/CTCSS scan can be started by pressing the [* SCAN] button.
• 4. RXCTCS - Receiver Continuous Tone-Coded Squelch System. Squelch unlocks only if the specified code is received. A DCS/CTCSS scan can be started by pressing the [* SCAN] button.
• 5. TXDCS - Transmitter Digital-Coded Squelch. Radio sends the specified code during transmission.
• 6. TXCTCS - Transmitter Continuous Tone-Coded Squelch System. Radio sends the specified code during transmission.
• 7. TxODir - Transmitter frequency offset direction.
• 8. TxOffs - Transmitter frequency offset value.
• 9. W/N - Bandwidth used by transceiver (WIDE - 25kHz, NARROW - 12.5kHz).
• 10. Scramb - Scrambler function to distort audio for privacy.
• 11. BusyCL - Busy channel lockout. Prevents transmission if a signal is already being received.
• 12. Compnd - Compander function to improve audio quality over limited dynamic range facilities.
• 13. Demodu - Demodulator mode (default FM, AM/USB for listening only).
• 14. ScAdd1 - Add channel to scan list 1.
• 15. ScAdd2 - Add channel to scan list 2.
• 16. ChSave - Save current setting to a memory channel.
• 17. ChDele - Delete memory channel.
• 18. ChName - Modify memory channel name. (Details on editing process).
• 19. SList - Selects channel for memory channel scanner.
• 20. SList1 - Channels assigned to scan list 1.
• 21. SList2 - Channels assigned to scan list 2.
• 22. ScnRev - Scan resume mode (CARRIER, TIMEOUT, STOP).
• 23. F1Shrt - Side button 1 short press function.
• 24. F1Long - Side button 1 long press function.
• 25. F2Shrt - Side button 2 short press function.
• 26. F2Long - Side button 2 long press function.
• 27. M Long - Menu button long press function.
• 28. KeyLck - Auto keypad lock option.
• 29. TxTOut - Maximum transmission time limit.
• 30. Batsav - Battery save option.
• 31. Mic - Microphone sensitivity.
• 32. MicBar - Microphone bar display during transmission.
• 33. ChDisp - Channel display style.
• 34. POnMsg - Power-on message.
• 35. BatTxt - Additional battery value display (% or volts).
• 36. BackLt - Backlight duration.
• 37. BLMin - Minimum backlight brightness.
• 38. BLMax - Maximum backlight brightness.
• 39. BltTRX - Backlight activation on TX or RX.
• 40. Beep - Keypad press beep sound.
• 41. Roger - Roger beep at end of transmission.
• 42. STE - Squelch tail eliminator.
• 43. RP STE - Repeater squelch tail eliminator.
• 44. 1 Call - One key call channel.
• 45. ANI ID - DTMF communication radio ID.
• 46. UPCode - DTMF code sent at beginning of transmission.
• 47. DWCode - DTMF code sent at end of transmission.
• 48. PTT ID - Sets if UPCode and/or DWCode should be transmitted.
• 49. DST - DTMF side tone switch.
• 50. D Resp - DTMF decoding response (DO NOTHING, RING, REPLY, BOTH).
• 51. D Hold - DTMF auto reset time.
• 52. D Prel - DTMF pre-load time.
• 53. D Decd - Enables DTMF decoder.
• 54. D List - List of DTMF contacts.
• 55. D Live - Displays DTMF codes received by radio.
• 56. AM Fix - Activates autogain AM fix function.
• 57. vox - Voice TX activation sensitivity level.
• 58. BatVol - Battery voltage and percentage.
• 59. RxMode - Sets how upper and lower frequency are used (MAIN ONLY, DUAL RX RESPOND, CROSS BAND, MAIN TX DUAL RX).
• 60. Sql - Squelch sensitivity level.

Hidden Menu

The hidden menu is activated by holding [PTT] + [SIDE BUTTON 1] while turning on the radio, then releasing all keys.

• 61. F Lock - Sets the TX frequency band plan. Options include:
  • DEFAULT+ (137-174, 400-470) - Allows TX on default bands, plus options Tx 200, Tx 350, Tx 500.
  • FCC HAM (144-148, 420-450)
  • CE HAM (144-146, 430-440)
  • GB HAM (144-148, 430-440)
  • (137-174, 400-430)
  • (137-174, 400-438)
  • DISABLE ALL - Disables TX on all frequencies.
  • UNLOCK ALL - Enables TX on all bands (requires additional lock configuration, see wiki).
• 62. Tx 200 - Enables TX on 200MHz.
• 63. Tx 350 - Enables TX on 350MHz.
• 64. Tx 500 - Enables TX on 500MHz.
• 65. 350 En - Enables RX on 350MHz.
• 66. ScraEn - Enables scrambler function.
• 67. BatCal - Battery calibration. Measures voltage and adjusts the value.
• 68. BatTyp - Battery type (e.g., 1600mAh, 2200mAh) affects battery level percentage calculation.
• 69. Reset - Resets radio configuration settings (VFO for channel settings only, ALL for all settings).