Month: May 2018

When you use both HF+ and IC-7410, it would be convenient if the two frequencies are in sync across the equipment.

There could be various ways to realize that, and here is one:

# filename = airspy_ic7410_telnet.py
# % rigctld -m 367 -r /dev/ttyUSB0 &
# % python3 airspy_ic7410_telnet.py
#
import time
import telnetlib
HOST  = "127.0.0.1"
PORT1 = 7356 # GQRX    default port
PORT2 = 4532 # rigctld default port
EXPECTED =b"dummy"
TOUT = 0.5

f1b4 = 0
f2b4 = 0

tn1 = telnetlib.Telnet(HOST, PORT1)
tn2 = telnetlib.Telnet(HOST, PORT2)

tn1.read_until(EXPECTED, timeout=1); # to discard everythng
tn2.read_until(EXPECTED, timeout=1);

while (True):
    time.sleep(1.0)
    
    tn1.write(b"f\n")
    f1 = int(tn1.read_until(EXPECTED, timeout=TOUT).decode('ascii'))
    if (f1 != f1b4):
        f1b4 = f1
        new_f2=b"F "+str(f1).encode('ascii')+b"\n"
        tn2.write(new_f2)
        tn2.read_until(EXPECTED, timeout=TOUT)

    tn2.write(b"f\n")
    f2 = int(tn2.read_until(EXPECTED, timeout=TOUT).decode('ascii'))
    if (f2 != f2b4):
        f2b4 = f2
        new_f1=b"F "+str(f2).encode('ascii')+b"\n"
        tn1.write(new_f1)
        tn1.read_until(EXPECTED, timeout=TOUT)

This small program uses telnet to talk to HF+ (via Gqrx) and to IC-7410 (via rigctld).

With Ubuntu 18.04, the settings are almost the same as with macOS except for the Audio Settings as is shown in the following figure.

Let’s see if my new SDR works fine with FT8.

The operating system is macOS High Sierra (10.13.4).

I use Soundflower to send the audio stream from Gqrx to WSJT-X.

---

Now the settings for Gqrx. Remember that the Mode must be USB.

The Audio output should be either “Multi-Output Device” or “Soundflower (2ch)”.

Do not forget to enable Remote control (Tools -> Remote control).

---

Finally, the settings for WSJT-X.

“Hamlib NET rigctl” is selected as rig control.

Select “Soundflower (2ch)” for Soundcard Input.

You can control Gqrx using telnet.

import numpy as numpy
import matplotlib.pyplot as plt
import telnetlib
HOST = "127.0.0.1"
EXPECTED =b"dummy"
TOUT = 0.1

tn = telnetlib.Telnet(HOST, 7356)
xvalue = []
yvalue = []

tn.write(b"M CW 1000\n")
print(tn.read_until(EXPECTED, timeout=TOUT).decode('ascii'), end="")

for freq_hz in range(79000000, 81000000, 1000):
	freq=b"F "+str(freq_hz).encode('ascii')+b"\n"
	tn.write(freq)
	tn.read_until(EXPECTED, timeout=TOUT)

	tn.write(b"f\n")
	f = int(tn.read_until(EXPECTED, timeout=TOUT).decode('ascii'))
	xvalue.append(f)
	print(f)

	tn.write(b"l\n")
	l = float(tn.read_until(EXPECTED, timeout=TOUT).decode('ascii'))
	yvalue.append(l)
	print(l)

plt.figure(1, figsize=(8,8))
plt.subplot(111)
plt.title('Airspy HF+')
plt.xlabel('Freq [Hz]')
plt.ylabel('Signal Strength [dBm]')
plt.grid(True)
plt.plot(xvalue, yvalue, color='blue', linewidth=1)
plt.show()

The program scan the FM band, and plot the signal strength.

Obviously, you wish to use your SDRs on more reasonable Operating Systems.

This is Gqrx on Ubuntu 18.04.

And Gqrx also runs on macOS.

Airspy HF+ is natively supported by Gqrx under both operating systems.

Gqrx can be controlled remotely via telnet.

% telnet localhost 7356
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
f
7027000
F 7031000
RPRT 0
f
7031000
M ?
OFF RAW AM FM WFM WFM_ST WFM_ST_OIRT LSB USB CW CWU CWR CWL
M CW
RPRT 0
m
CW
500
M CW 300
RPRT 0
m
CW
300
q
Connection closed by foreign host.

The list of available commands is here: remote-control.txt.

Ordered on April 22, and delivered on May 8.