Gordon,
The early QDX kit builders (I was one) had to rework the first released boards of the QDX to remove four SMD 47uH chokes and replace them with through-hole inductors.? The reason given was that the chokes' self-resonance changed the filter characteristics.? Could that be the issue here as well?
The equivalent inductors to replace would be L202, L4, L5, L3, and L2.??
Ashhar Farhan stated that the LPF PIN diode switch design was based on Hans Summers' work.? Hans is the designer of the QDX.
I do not own a V2, so I can not verify your tests.? As stated before, the DE I have meets all FCC requirements as far as I can test.? The DE uses relays to switch the LPFs.? This would support your theory that there is an issue with the filter selection circuits.
73
Evan
AC9TU
