KD8CEC firmware hint – CW frequency display

The KD8CEC firmware provides a lot of customisation features through uBITx Manager software.  Many user of Ian’s firmware are not aware of all the built-in features of his firmware.   This is one such instance!

JJ1EPE raised a concern that his display in CW mode was “off frequency”.  Well, it was from his perspective, but then the display was all the time showing the TX frequency not the offset frequency where the station he was listening to.

CW offsets create headaches in how you represent the frequency on a display.  In SSB the frequency you see on the display is the frequency of the suppressed carrier on receive and the same on transmit.   If you tune to the carrier frequency of a received station you won’t hear anything.  To get a sidetone we have to tune off the transmit frequency by a few hundred hertz.  Most people have worked out how to set the offset on the uBITx.

The standard that Ian KD8CEC has applied is to always show the TX frequency  by default (except where RIT or SPLIT mode is selected).

However, if you want to change the approach, do the following in uBITX Manager:

– Enable Adjust CW Frequency

– Shift Display Frequency on CWL, CWU Mode

If you select this function, the LCD will show the frequency at which the radio is being transmitted (the offset you prefer is added or subtracted to the actual RX frequency reflecting the CW-L or CW-U mode selected).   This may be just the thing you were looking for!


2 Replies to “KD8CEC firmware hint – CW frequency display”

  1. I just finished my V4 uBitX with CEC 1.10 firmware and the V3 Nextion GUI. I think the method of offsetting the transmit frequency is backwards to how CW offset should be done. Although this works, it can have bad consequences. If the other station is transmitting on 14.100 I will not hear him unless I tune the uBitX to 14.099300 if I am particular about hearing a 700Hz tone and I am using CWU, so that means I actually will be transmitting on 14.100 when I send back and he will hear me. Similarly, if I have selected CWL I won’t hear him until I set the receiver to 14.100700 and I will be transmitting back on his frequency. However, we should be indicating the actual transmit frequency, not where I have offset to hear the other station. If I was close to the lower band edge, and I wanted to call CQ on 14.000500, I would actually be transmitting 200Hz below the band limit if I have selected CWL mode. Other rigs I have used, even Allard’s sketch for the BitX40, offset the receiver by the amount of the desired tone (offset), either up or down based on if CWU or CWL is selected, so the transmitter always is sending on the dial frequency.

    1. Update: Dr. Lee addressed this issue in the latest version of the software and Memory manager! If you select the boxes “Enabled Adjust CW Frequency” and “Shift Display Frequency on CWL, CWU Mode” and leave the “CW Freq Adjust Value” at zero (this adds to the CW offset or CW tone selected elsewhere), then the receiver will automatically shift up or down by the amount of the selected CW tone and appropriately for CWL and CWU such that the transmitter will be transmitting on the displayed frequency. Well done!

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