Re: uBitx Modulation only lows no highs in frequency response


With my radio/engineering skills very much lacking, I probably don't even need to be trying to contribute to this conversation, but here is what I ran into on my build. My tx audio was very distorted when I first tested. I then checked the transmit using the tones sent from WSJTx. I found that no tones were passing that were around 500hz or lower, but higher tones around 1600hz caused more power to be output from the radio. I adjusted the  BFO until I had maximum power out when sending a 1khz tone. This gave me power out in a range from 200hz to 1600hz. This seemed to clean up the audio on SSB. Apparently I have a very narrow filter, but I am getting good audio reports on SSB. The down side is that with it being so narrow, when operating FT8, I need to shift the VFO frequency to see all the transmissions. If I remember right, to shift the audio frequency down, I had to adjust the BFO frequency up, but please don't hold me to this statement . I did adjust about 100hz at a time, and checked the power out using different frequencies generated by WSJTx. I don't exactly know what the above means, but it did help me to have a good working radio. Hope this helps someone. 

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