The primary selling point of the uBitx is its simplicity,
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would be good to keep it that way.
The circuit improvements moving from V4 to V5 are a major win,
badly needed and no significant added complexity.
Though I would have kept the +12V for the IRF510's separate, much safer to
debug all but the final amp of the transmitter with those IRF510's disabled.
And allows flexibility in setting the output power by adjusting the IRF510 supply voltage.
A simple way to adjust RF gain would be good.
Moving from the V5 16x2 LCD to the V6 TFT display adds lots of overhead
to the Nano's firmware. I'd prefer the uBitx had kept the 16x2, at least as an option.
An SWR meter and antenna tuner with a suitable dummy load for the uBitx
might be a good accessory. Audio and RF signal generators, a diode RF probe
(or AD8307), complete instructions to debug the rig, those would be most welcome.
Perhaps make them all part of a single accessory? An audio CW filter too?
On Sat, Oct 24, 2020 at 05:49 PM, Bob Lunsford wrote:
Using a tuner on an antenna that is designed/dedicated to a specific band or frequency would theoretically funnel the signal to that specific frequency but it would also, theoretically, suppress received signals up and down frequency from the tuner's settings. Since it is also a good approach to getting as much power as possible from a QRP radio to the antenna by allowing the transmitter's output stage to see a much better load and lessen the complications of a mismatch, it would/should be an automatic part of the system unless weight or system complexity are concerns. It is undoubtedly a prime candidate for experimentation to see if a tuner does indeed reduce the influence of a high powered transmitter either nearby in frequency or location.
Thanks, Curt, for your feedback on this. Sometimes a simple solution may be best even if not a complete solution. I agree that AGC may be nice but it is not always the best or necessary. For example, on my G90 if you turn off the AGC it reveals many weak stations and even if some others come booming in, it's a small price to pay to guarantee that all stations on the [net] frequency are heard. Unless it is truly excessive in volume, of course, and this is "in the ear of the hearer."
Bob — KK5R