Re: QMX V3? What does V3 bring?
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Hello Colin
The BPF is a series resonant LC circuit, and a 1:4 multiplexer selects one coil tap of the inductor, and one capacitor. There are a lot of parasitic elements present in the circuit, including PCB trace inductances and capacitances, and the capacitance of the MUX chip input pins, self capacitance of inductor windings, and probably more.?
I expected QMX and QDX would be the same on this area. Nobody more surprised than me. But somehow the interaction of the parasitic elements managed to change everything.
Exactly how: still a mystery!
73 Hans G0UPL
Hans, I love reading your updates and circuit theory. I was wondering if you had an update to the cause of the V1 receiver change? I still find it amazing that the QDX and the QMX V1 receiver filters do not?function not the same. Colin - K6JTH
Hello Dave
Sorry for the lack of clarity. There are 1,000 PCBs arriving here in 2-3 days which cleared customs today. They are all Rev 3. So all pending kit orders will be shipped Rev 3 boards.?
73 Hans G0UPL
On Tue, Feb 13, 2024, 8:09?PM Dave Schmidt < dgschmidt@...> wrote: Thanks for the info Hans!
So is the shipment of V2 boards you are waiting for going to ship as V3?? Or is V3 still in fab?
Dave
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Colin - K6JTH?
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