On Wed, Jun 21, 2023 at 10:14 AM, Don, ND6T wrote:
If new builders want to duplicate this fix might avoid making the 19th turn tap on L401 and not install C403. The value of the new capacitor is not critical, it just needs to block the DC bias but pass the 14 MHz receive signal when that band is selected. It could be a leaded part, placed from the hole at the input end of the C403 position to the hole where the 19th tap was supposed to go.
Don, why not put the capacitor in place of C403 and short the L401 tap separately? Is something avoided by not using the PCB trace from the capacitor to the inductor tap?
I ask because I'm trying to do something similar on a QDX, and shorted 2 inductor holes and used an 820pf capacitor in a BPF capacitor spot, but my rf sweeps still all peak 1-2 Mhz higher than the target frequency.??
Nate
N8BTR
