by 5B4AIY » 04 Dec 2018 07:11
Hi Greg,
Glad that you have managed to load the new firmware. As for calibrating the frequency counter, refer to the instructions on page 18 of the User Manual. With an input power of 100mW to 5W, not critical, inject an accurately known CW signal on 10m. I suggested the default Juma TRX-2 10m band select frequency in the firmware I modified for that transceiver, but as long as you know the frequency, and it is an integer number of kilo-hertz, that will be fine. For example, use 28,850kHz.
Using the UP button step up until the display just reads 28.849 without any jitter, and note this calibration figure. Now using the DOWN button step down until the display just reads 28.851 without any jitter. Add the upper and lower calibration figures, and then divide by 2 and use the integer result. For example, in my case the two calibration figures were: 1,000,003 and 999,966 adding these gives: 1,999,969 and dividing this by 2 gives: 999984.5, so the actual calibration factor is: 999,984. It is important that the input frequency is set to an exact number of kHz, and that its frequency is known to better than +/-100Hz.
Glad to have been of assistance.
73, Adrian, 5B4AIY