After some research on the Internet. I concluded this.
MFJ-1026 Noise Canceller modification Plan
1. Reduce Low frequency attenuation (increase gain at 1.8 MHz)
- Change C8, C16 (680pF) with 1.6nF for Better high pass filtering
- Change C18 (680pF) with 1.6nF for better pass through
- May Change L3, L4, L5, L6 (5.6 uH) with 10 uH ==> No need to change (Just Increase Cap to decrease attenuation at 1.8 Mhz)
2. Better IM Dynamic range
- Remove Diodes D6, D9, D10, D11
3. Better Gain
- Add 4:1 transformer to the output of Q4 (C1)
4. Better control of Phase range (Swap inputs)
- ADD DPDT SW & Coax to swap the inputs of Q8 and Q5
- Q8 -> SW -> R20; Q5 -> SW -> R9
5. Getting Better phase range and control
- Change C13 (120pF) with (47pF => 68pF) - Increased range for high band position
- Change C12 (470pF) with 680pF - Better phase control for low band position
6. Protect Aux Antenna FET from high power operation
- Install an AUX antenna input grounding Relay.
- Connect Relay (+) to (C2-Q1 junction pad) and Relay (-) to (R5-Q2 junction pad), -Install a diode
- Install a protection diode
- Need a 12V relay for isolation and a Diode for protection (NA1S TQ2-12V, Single side stable)
1. Download Raspberry pi Image from https://www.openwebrx.de/download/rpi.php
2. Burn image to 16GB SD card
3. Install SD card and RTL-SDR into the RPi3B
4. login to local terminal, user/pass = pi/raspberry
5. run "sudo raspi-config" for initial setup
6. setup configuration file for OpenwebRX
cd /etc/openwebrx
sudo nano config_webrx.py
Go to "Anaconda Prompt"
0. check Conda
conda list # list library
conda update --all # Updates all libraries
conda --version
python --version # --version shows version of the library
1. Create environment
conda create -n py38 python=3.8
conda activate py38 # activate the environment
conda deactivate py38 # deactivate
2. Install keras version
conda install -c anaconda keras-gpu #GPU 버전
conda install -c anaconda keras #CPU 버전
3. Install other packages
conda install -c anaconda pandas # pandas
conda install -c anaconda xlrd
conda install -c anaconda xlwt # excel 파일을 pandas에서 읽고 쓰기
conda install -c anaconda seaborn # 데이터 시각화
conda install -c anaconda scikit-learn # 사이킷런
conda install pillow # 이미지 처리
4. Check at Python/Spyder
import tensorflow as tf
import keras as k
print("Version of Tensorflow = ", tf.__version__)
print("Version of keras = ", k.__version__)
PROBLEM - Dell recovery media does NOT recognize NVME SSD
Solution - Found at Dell support page in
https://www.dell.com/support/article/ko-kr/sln310971/
The LG AN-WF100 USB Wi-Fi dongle left, after trashing the TV.
This dongle uses a generic Broadcom chipset. To use the dongle at Windows 7 PC
1. Download a compatible driver from http://www.downloads.netgear.com/files/GDC/WNDA3100V2/WNDA3100v2_V2.2.0.5.zip
2. Install the driver normally. Close application
3. Remove/Disable WNDA3100v2.exe from the strat-up entry
4. Now plug-in the LG dongle to your PC. It will be detected as an unknown “Remote Download Wireless Adapter” device.
5. Open Device Manager, right-click the unknown “Remote Download Wireless Adapter” device, select “Update Driver…”, choose to browse for the driver.
6. Select the “Network adapters” category, scroll down to “Netgear”, select “Netgear WNDA3100v2 N600 Wireless Dual Band USB Adapter”.
7. Just Ignore the warning about driver compatibility.
That's it.
O Prepared gears:
- Raspberry Pi3B with >8GB SDHC
- Old RTL-SDR dongle
Setting up
1. Prepare RPi3B
- Install the latest image from https://www.raspberrypi.org/downloads/raspberry-pi-os/
sudo raspi-config
In the localization settings change the timezone to UTC (localization options -> time zones -> none of the above -> UTC
2. Install RTL-SDR drivers
sudo apt-get update sudo apt-get install libusb-1.0-0-dev git cmake -y git clone https://github.com/keenerd/rtl-sdr cd rtl-sdr/ mkdir build cd build cmake ../ -DINSTALL_UDEV_RULES=ON make sudo make install sudo cp ../rtl-sdr.rules /etc/udev/rules.d/ sudo ldconfig echo 'blacklist dvb_usb_rtl28xxu' | sudo tee --append /etc/modprobe.d/blacklist-dvb_usb_rtl28xxu.conf
Now reboot to apply the blacklist, and plug in your RTL-SDR.
Need PulseAudio to create virtual audio cables. Also install mplayer for playing the audio.
sudo apt-get install pulseaudio pavucontrol mplayer -yCSDR is a library of DSP functions that we'll use to set up a multi-channel receiver.
sudo apt-get install libfftw3-dev -y
cd ~
git clone https://github.com/simonyiszk/csdr
cd csdrBefore going any further, for the Pi 3 we recommend editing the Makefile and changing the PARAMS_NEON flags to the following. The Makefile can be opened with
"sudo leafpad Makefile"
-march=armv8-a -mtune=cortex-a53 -mfpu=neon-fp-armv8.
Also under PARAMS_RASPI set:
-mcpu=cortex-a53 -mfpu=neon-fp-armv8.
We're not sure if it actually does anything, but the idea is that this should help optimize the code for the Pi 3 CPU. For any other SBC, you'll want to check what these settings should be for your architecture.
Close and save the file, then run:
make sudo make install
The ncat is a TCP server that we'll use to help us set up a multi-channel receiver.
sudo apt-get install nmap -y
We'll use Chrony to adjust the time offset required by these QRP modes. The configuration will be discussed later.
sudo apt-get install chrony -y
Go to the WSJT-X page in Chrome, download the .deb file for the Raspberry Pi, And Install it.
8. Audio Piping Setup
Need to create virtual audio sinks for each frequency that you want to simultaneously monitor. The example below will set up two virtual audio sinks that load on boot.
To set up another, simply add more lines from Virtual 2 and and so on. First open the pulseaudio default.pa file:
sudo leafpad /etc/pulse/default.paAdd the following lines to the end of the file:
load-module module-null-sink sink_name=Virtual0 sink_properties=device.description="Virtual0"
load-module module-null-sink sink_name=Virtual1 sink_properties=device.description="Virtual1"Disabling PulseAudio logging is recommended, as this seems to be a large user of CPU cycles.
sudo leafpad /etc/pulse/daemon.conf
Find "log-level" and change it to "log-level = error".
; log-target = auto log-level = error ; log-meta = no
Now reload pulseaudio either by rebooting, or running "pulseaudio -k" at a command line.
Set up an RTL-SDR TCP server with ncat. In this example, the center frequency is set to 14.1 MHz (14100000 Hz).
Change this to whatever frequency band you want to monitor. Just remember to offset the center frequency by a few hundred kHz from the actual signal frequency to help avoid the center DC spike.
======
pi@raspberrypi1:~ $ rtl_sdr -s 1200000 -f 14100000 -D 2 - | csdr convert_u8_f | ncat -4l 4952 -k --send-only --allow 127.0.0.1 Found 1 device(s): 0: Generic, RTL2832U, SN: 77771111153705700 Using device 0: Generic RTL2832U Found Elonics E4000 tuner Enabled direct sampling mode, input 2 Enabled direct sampling mode, input 2/Q. Sampling at 1200000 S/s. Tuned to 14100000 Hz. Tuner gain set to automatic. Reading samples in async mode...
======
pi@raspberrypi1:~ $ ncat -v 127.0.0.1 4952 | csdr shift_addition_cc `python -c "print float(14100000-14074000)/1200000"` | csdr fir_decimate_cc 25 0.05 HAMMING | csdr bandpass_fir_fft_cc 0 0.5 0.05 | csdr realpart_cf | csdr agc_ff | csdr limit_ff | csdr convert_f_s16 | mplayer -nocache -rawaudio samplesize=2:channels=1:rate=48000 -demuxer rawaudio -
csdr bandpass_fir_fft_cc: window = HAMMING
csdr bandpass_fir_fft_cc: (fft_size = 256) = (taps_length = 79) + (input_size = 178) - 1
(overlap_length = 78) = taps_length - 1
fir_decimate_cc: taps_length = 79
csdr fir_decimate_cc: taps_length = 79
csdr fir_decimate_cc: padded_taps_length = 80
csdr fir_decimate_cc: taps = 7c8018
csdr fir_decimate_cc: NEON aligned taps = 7c8020
Ncat: Version 7.40 ( https://nmap.org/ncat )
csdr bandpass_fir_fft_cc: filter initialized, low_cut = 0, high_cut = 0.5
Ncat: Connected to 127.0.0.1:4952.
csdr shift_addition_cc: reinitialized to 0.0216667
MPlayer 1.3.0 (Debian), built with gcc-6.2.1 (C) 2000-2016 MPlayer Team
do_connect: could not connect to socket
connect: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.
Playing -.
Reading from stdin...
rawaudio file format detected.
Load subtitles in ./
==========================================================================
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 48000 Hz, 1 ch, s16le, 768.0 kbit/100.00% (ratio: 96000->96000)
Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
==========================================================================
AO: [pulse] 48000Hz 1ch s16le (2 bytes per sample)
Video: no video
Starting playback...
^C 8.7 (08.6) of 0.0 (unknown) 29.2%
MPlayer interrupted by signal 2 in module: play_audio
A: 8.7 (08.7) of 0.0 (unknown) 29.0% =====
lsusb. lsusb again.dmesg -H
lsusb lsusb again.dmesg -H/dev/ttyUSB0 and that its serial number is 0001
lsusb .
