KC901 J/K/R Firmware Download

KC901K equipped with firmware upgrade function, you only need to deposit the ROM package into the TF (micro SD) card and follow the instructions to complete the upgrade without other settings.

The maximum supported TF card capacity is 32GB with FAT32 file system. Large capacity TF cards may have compatibility issues.

If the firmware version of your KC901J/K/R is less than 1.1.2, you have to upgrade the Boot loader first, note that you have to be careful when upgrading the Bootloader to make sure the power is enough, otherwise your instrument may be damaged and need to be sent back to us for repair.

Update Guide

ROM Pack Download

Bootloader
1.2.2.zip

Version 1.2.2 , released Apr 14, 2025.

Supports KC901J/K/R

This update contains two files, the bootloader updater 2.01MB and the firmware 5.56MB, both of which have the same name and are only distinguishable by size.

First of all, to upgrade the bootloader, you must keep the KC901 battery voltage higher than 7.3V. or it will cause an error.

Upgrade method is the same as a normal upgrade, copy the bootloader file to the card and insert to KC901, Hold 3 buttons and power on.

After the upgrade is completed, restart the KC901, the program will run during the restart process, after the runtime is completed KC901 will power on. at this time it will show RF Error, which is normal.(In some unkowen situation KC901 will not shows the UI, If the screen shows success you can turn off the KC901 and do next step)

Then copy the firmware 5.46MB to the memory card and perform the upgrade again. Note that when you enter the upgrade interface, the bootloader version 0.03 should be displayed.

After this operation, you KC901 should be update successful.
Update:
Added Function – In Spectrum and Field Strength modes, you can turn on the RF signal source output. The signal source cannot use modulation in this state.
Added output power setting in the S-parameter mode, which allows you to specify the specific output power, with the setting item under the SCALE menu (the output power setting in DTF mode is located in the leftmost soft menu). The shift+SCALE shortcut function has been modified too. Deleted the output gain setting item in the FUNC menu.
Power consumption will increase by about 5% to 10% when output control is used, and it is more power-saving when using gain control and set to 0 dB or lower.
If the output power set exceeds the maximum output capacity of the instrument, it is indicated by a *. This version also optimizes the markers so that the maker can be aligned to the scanning frequency (before this version it is be interpolated by pixel equals), making the cursor frequency easy to round up.
The logic of using the HOME key has been modified.
Adjusted the logic of S-parameter trace opening, and changed the default opening of multiple traces to a single trace by default, and the multiple traces will be displayed only when the user opens them manually. Repair more than 60 defects, such as “when the gain is -20dB, the system calibration, open circuit, SWR mode appears more abnormal points”. Revised remote control command for field strength function. And other optimizations.
1.0.9.zip

Version 1.0.9 , released Dec 2, 2024.

Supports KC901J/K/R

1, optimize power consumption, add stop and pause function: press Run/Stop button for 0.5 seconds to enter the stop mode, at this time the RF module will be completely powered off to enter the deep power saving mode. In this state KC901x can standby for more than 24 hours. Press Run/Stop button again to re-run. Since the firmware needs to be reloaded when resuming, it needs to wait for about 3.5 s. Pressing Run/Stop briefly will enter the pause mode.
2, add switching between high and low local oscillator for S-parameter measurement in the FUNC menu, this function belongs to the advanced function, users do not need to switch.
3, add sweep delay function in FUNC menu, used to realize low-speed S-parameter measurement.
4, optimize the power consumption of signal source function.

Known issues

The full dual-port calibration algorithm is inaccurate, it is recommended not to use full dual-port calibration for the time being.

1.0.6.zip

Version 1.0.6 , released Nov 15, 2024.

Supports KC901J/K/R
Improve 20% measurement speed
Improve the measurement speed and stability of KCSDI connection
Fixes the problem of wrong measurement phase in some cases (KC901R)
Add SD card insertion prompt
Fix the problem of Marker menu not working properly under DTF measurement.

Known issues
Noise increase during multi-curve measurements in some cases
The STEP parameter display at the top of the UI has a refresh bug and can be ghosted. This can be resolved by re-selecting the measurement mode once in the HOME menu.

1.0.3.zip
Version 1.0.3(BETA) , released Oct 29, 2024. now abandoned

Multi-trace support, improve the measurement speed, this is beta test version, there may be unknown bugs.

0.1.3.zip
Version 0.1.3 , released May 19, 2024.

Add DTF function and fix some bug.

Currency
$ United States (US) dollar
€ Euro