My current info:
1 - Raspbian Buster version 10 on Raspberry Pi 4?
2 - QDX version v1_01a
3 - Built for 12 volts
4 - 12 volt LitionIon
5 - Rev 1 board
6 - I have removed the 4 PA BS170 MOSFETs and IC5 as those were damaged in prior testing
Trying to find out how to adjust the Band Pass Filter to better align the RF sweeps.? I could not find it in the manual.? Is there a separate troubleshooting document?? This is related to a low signal input to the PC.? I wanted to rule out the filter before I start tearing into the audio chain starting with IC7.? I have already determined that IC4 and IC9 are working as expected, and the voltage to the input of the sampling mixer is at 1/2 Vcc as expected.? I have a very low I/Q signal at the outputs of IC7 (LM4562).
Further info:??I do get some stations detected in WSJT-X, though not as many as when I use the same antenna with my other digital mode capable radios.
I have already maxed out the Raspbian input level and have the audio gain set for 80000.? This seems to work, however, I am surprised that the gain had to be raised from 5000 to 80000 to get the input to WSJT-X version 2.0.0 up to 40 DB.
Filter Scans:
Again, I am trying to find out the best process to tweak the bandpass input filter.
73
Evan
AC9TU
