Today I soldered the original BPF configuration into my QMX 20-10.
Preliminary I bypassed the 20m LPF, and I left out the two other LPFs.
I configured all bands to use the LPF bypass and can sweep through the BPFs through all bands.
Everything works fine as I am used from the QMXs, but not as simulated ;-)
The band pass filter is much steeper than my simulation!
=> My assumption is wrong: I can't use the 10m BPF for 6m.
Maybe my configuration for the simulation is wrong?
- Did I use the right impedance (50 Ohm)?
- Is my circuit for the simulation correct??
I understand the BPF like this:
?
RX IN ------ L ------ C ------- OUT
GND ---------------------------- GND
?
Is this too simplistic? Is T401 to be seen as essential part of the BPF?
?
73 Peter DL4PJ
