Re: Sustained Transmit Power #firmware

Tom, wb6b

I ran a WSPR beacon with my uBITX for several weeks. I found that it was rare for the TX frequency to drift during a transmit cycle. And only a HZ if it did.

I ran a fan on the heatsinks and the heatsink temperature was warm but not hot.  I ran a 20% TX/RX duty cycle. But 50/50 may not be much different. 

It was tricky to get the PPM adjustment right in the WSJT-X WSPR software. The big source of confusion was I could not get the PPM adjustment to converge on the desired frequency. That turned out to be, when using the CAT interface from WSJT-X to the uBITX, the uBITX would only step in the same step size as programmed for tuning with the frequency dial. Setting the frequency step to the minimum step size fixed that issue.

Tom, wb6b

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