kopia lustrzana https://github.com/NanoVNA-Saver/nanovna-saver
163 wiersze
6.1 KiB
Python
163 wiersze
6.1 KiB
Python
# NanoVNASaver
|
|
#
|
|
# A python program to view and export Touchstone data from a NanoVNA
|
|
# Copyright (C) 2019, 2020 Rune B. Broberg
|
|
# Copyright (C) 2020, 2021 NanoVNA-Saver Authors
|
|
#
|
|
# This program is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
import logging
|
|
import math
|
|
|
|
import numpy as np
|
|
# pylint: disable=import-error, no-name-in-module
|
|
from scipy.signal import convolve
|
|
from scipy.constants import speed_of_light
|
|
|
|
from PyQt5 import QtWidgets, QtCore
|
|
|
|
from NanoVNASaver.Windows.Defaults import make_scrollable
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
CABLE_PARAMETERS = (
|
|
("Jelly filled (0.64)", 0.64),
|
|
("Polyethylene (0.66)", 0.66),
|
|
("PTFE (Teflon) (0.70)", 0.70),
|
|
("Pulp Insulation (0.72)", 0.72),
|
|
("Foam or Cellular PE (0.78)", 0.78),
|
|
("Semi-solid PE (SSPE) (0.84)", 0.84),
|
|
("Air (Helical spacers) (0.94)", 0.94),
|
|
# Lots of cable types added by Larry Goga, AE5CZ
|
|
("RG-6/U PE 75\N{OHM SIGN} (Belden 8215) (0.66)", 0.66),
|
|
("RG-6/U Foam 75\N{OHM SIGN} (Belden 9290) (0.81)", 0.81),
|
|
("RG-8/U PE 50\N{OHM SIGN} (Belden 8237) (0.66)", 0.66),
|
|
("RG-8/U Foam (Belden 8214) (0.78)", 0.78),
|
|
("RG-8/U (Belden 9913) (0.84)", 0.84),
|
|
# Next one added by EKZ, KC3KZ, from measurement of actual cable
|
|
("RG-8/U (Shireen RFC®400 Low Loss) (0.86)", 0.86),
|
|
("RG-8X (Belden 9258) (0.82)", 0.82),
|
|
# Next three added by EKZ, KC3KZ, from measurement of actual cable
|
|
("RG-8X (Wireman \"Super 8\" CQ106) (0.81)", 0.81),
|
|
("RG-8X (Wireman \"MINI-8 Lo-Loss\" CQ118) (0.82)", 0.82),
|
|
("RG-58 (Wireman \"CQ 58 Lo-Loss Flex\" CQ129FF) (0.79)", 0.79),
|
|
("RG-11/U 75\N{OHM SIGN} Foam HDPE (Belden 9292) (0.84)", 0.84),
|
|
("RG-58/U 52\N{OHM SIGN} PE (Belden 9201) (0.66)", 0.66),
|
|
("RG-58A/U 54\N{OHM SIGN} Foam (Belden 8219) (0.73)", 0.73),
|
|
("RG-59A/U PE 75\N{OHM SIGN} (Belden 8241) (0.66)", 0.66),
|
|
("RG-59A/U Foam 75\N{OHM SIGN} (Belden 8241F) (0.78)", 0.78),
|
|
("RG-174 PE (Belden 8216)(0.66)", 0.66),
|
|
("RG-174 Foam (Belden 7805R) (0.735)", 0.735),
|
|
("RG-213/U PE (Belden 8267) (0.66)", 0.66),
|
|
("RG316 (0.695)", 0.695),
|
|
("RG402 (0.695)", 0.695),
|
|
("LMR-240 (0.84)", 0.84),
|
|
("LMR-240UF (0.80)", 0.80),
|
|
("LMR-400 (0.85)", 0.85),
|
|
("LMR400UF (0.83)", 0.83),
|
|
("Davis Bury-FLEX (0.82)", 0.82),
|
|
)
|
|
|
|
|
|
class TDRWindow(QtWidgets.QWidget):
|
|
updated = QtCore.pyqtSignal()
|
|
|
|
def __init__(self, app: QtWidgets.QWidget):
|
|
super().__init__()
|
|
self.app = app
|
|
|
|
self.td = []
|
|
self.distance_axis = []
|
|
self.step_response_Z = []
|
|
|
|
self.setWindowTitle("TDR")
|
|
self.setWindowIcon(self.app.icon)
|
|
|
|
QtWidgets.QShortcut(QtCore.Qt.Key_Escape, self, self.hide)
|
|
|
|
layout = QtWidgets.QFormLayout()
|
|
make_scrollable(self, layout)
|
|
|
|
self.tdr_velocity_dropdown = QtWidgets.QComboBox()
|
|
for cable_name, velocity in CABLE_PARAMETERS:
|
|
self.tdr_velocity_dropdown.addItem(cable_name, velocity)
|
|
self.tdr_velocity_dropdown.insertSeparator(
|
|
self.tdr_velocity_dropdown.count())
|
|
self.tdr_velocity_dropdown.addItem("Custom", -1)
|
|
self.tdr_velocity_dropdown.setCurrentIndex(1) # Default to PE (0.66)
|
|
self.tdr_velocity_dropdown.currentIndexChanged.connect(self.updateTDR)
|
|
layout.addRow(self.tdr_velocity_dropdown)
|
|
|
|
self.tdr_velocity_input = QtWidgets.QLineEdit()
|
|
self.tdr_velocity_input.setDisabled(True)
|
|
self.tdr_velocity_input.setText("0.66")
|
|
self.tdr_velocity_input.textChanged.connect(self.app.dataUpdated)
|
|
layout.addRow("Velocity factor", self.tdr_velocity_input)
|
|
|
|
self.tdr_result_label = QtWidgets.QLabel()
|
|
layout.addRow("Estimated cable length:", self.tdr_result_label)
|
|
|
|
layout.addRow(self.app.tdr_chart)
|
|
|
|
def updateTDR(self):
|
|
# TODO: Let the user select whether to use high or low resolution TDR?
|
|
FFT_POINTS = 2**14
|
|
|
|
if len(self.app.data.s11) < 2:
|
|
return
|
|
|
|
if self.tdr_velocity_dropdown.currentData() == -1:
|
|
self.tdr_velocity_input.setDisabled(False)
|
|
else:
|
|
self.tdr_velocity_input.setDisabled(True)
|
|
self.tdr_velocity_input.setText(
|
|
str(self.tdr_velocity_dropdown.currentData()))
|
|
|
|
try:
|
|
v = float(self.tdr_velocity_input.text())
|
|
except ValueError:
|
|
return
|
|
|
|
step_size = self.app.data.s11[1].freq - self.app.data.s11[0].freq
|
|
if step_size == 0:
|
|
self.tdr_result_label.setText("")
|
|
logger.info("Cannot compute cable length at 0 span")
|
|
return
|
|
|
|
s11 = [complex(d.re, d.im) for d in self.app.data.s11]
|
|
window = np.blackman(len(self.app.data.s11))
|
|
|
|
windowed_s11 = window * s11
|
|
td = np.abs(np.fft.ifft(windowed_s11, FFT_POINTS))
|
|
step = np.ones(FFT_POINTS)
|
|
step_response = convolve(td, step)
|
|
|
|
self.step_response_Z = 50 * (
|
|
1 + step_response) / (1 - step_response)
|
|
|
|
time_axis = np.linspace(0, 1 / step_size, FFT_POINTS)
|
|
self.distance_axis = time_axis * v * speed_of_light
|
|
# peak = np.max(td)
|
|
# We should check that this is an actual *peak*, and not just
|
|
# a vague maximum
|
|
index_peak = np.argmax(td)
|
|
|
|
cable_len = round(self.distance_axis[index_peak] / 2, 3)
|
|
feet = math.floor(cable_len / 0.3048)
|
|
inches = round(((cable_len / 0.3048) - feet) * 12, 1)
|
|
|
|
self.tdr_result_label.setText(f"{cable_len}m ({feet}ft {inches}in)")
|
|
self.app.tdr_result_label.setText(f"{cable_len}m")
|
|
self.td = list(td)
|
|
self.updated.emit()
|