Please be aware that the new v5 boards need to have the CEC version 1.2 or higher.? The IF frequency changed between the v4 and v5 boards.? IF you are going to go back to an older version of CEC for use on the v5 board you will need to go into the source and change the IF frequencies, recompile and then download.
Also be aware that the stock firmware requires a dummy load and separate receiver or frequency counter to calibrate.? The CEC software does not need the dummy load to calibrate.
The HF Signals' Tuneup web page instructions for step 2 are WRONG (Ashhar, this REALLY needs to be fixed!).? The stock firmware that I received on my v5 board put the uBITX into TRANSMIT mode at 10mhz.? Maybe this has changed with newer boards.
Since in my country (USA) 10MHz is not a valid ham frequency, a dummy load must be used.? I am pretty sure that this was done to facilitate the production testing/calibration process, however it does cause a problem if you are trying to calibrate and do not know that it will go into transmit mode at 10mhz.? It can also cause damage to the uBITX if left in this mode too long without a proper load. (note: QRP-Labs makes a nice 20 watt kit:?
For the stock firmware, dummy load and receiver/frequency counter setup, it is fairly easy to set the receiver to 10mhz (I assume that you calibrated the receiver/freq counter before this) and adjust the calibration until you get a zero beat on the receiver or 10 MHz on the counter.? Using a frequency counter, it is just a matter of connecting? to the counter through an attenuator to reduce the signal (the QRP-Labs dummy has a tap on it).? Most counters will work with a short wire held near the dummy load, no physical connection needed.? If you have an oscilloscope with a frequency counter built in, you could use it.? Most oscilloscopes are not that accurate, so I do not recommend this approach, unless being used as a relative reference.?
Once the master clock has been calibrated, I have found that the BFO is best adjusted with a free audio spectrum analyzer software.? Connect a mic to the PC, find a frequency with only static, hold the mic close to the speaker and adjust until the amplitude of the signal displayed is between 500 and 2500 Hz.
Free PC software:?
Above is my free advice, please use with caution as I could be wrong and will not assume any responsibility for it's use.
Good luck!
73
Evan
AC9TU
