Adventures in radio - February 2023
2023-02-23 The RCARC in person club meeting
My first in-person club meeting! I got my license in August 2020 and joined the Radio Central Amateur Radio Club (RCARC) a few months later. RCARC stopped in-person meetings earlier that year due to Covid restrictions, so I have only attended online until yesterday. The meeting was well attended, with at least a dozen members, and styled as a Chinese Auction, which was also a first for me. We had fun, and I even won a couple of auction items: a very nice custom hand-made CW paddle and an AEA MorseMachine.
A strong incentive to continue with the LICW classes, and I'll talk about them more when I get to play with them more. Both the paddle and the MorseMachine deserve to be "used in anger."
2023-02-21 SDR radio - software setup 3
Completed Installation and testing: As an aside, before continuing, if I was going to start all over again (I am not). I would do my testing and configuration with the SDR dongle being directly connected to my desktop, whether or not that be Windows, Linux, or something else. The irony of debugging and testing an essentially audio application over a non-audio headless terminal installation is not (at least now) lost on me.
Anyhow, using the Raspberry Pi VNC server for the connection mitigated many issues with the exception of the audio ones.
Linux audio setup and configuration can be a "black-art", not for the faint-of-heart and attempting Pulseaudio configuration risks a swift descent into driver loading madness.
I did, however, manage to compile and install GQRX and WSJT-X, both of which needed the desktop environment. Beware WSJT-X took *forever* to build and compile on a Raspberry Pi 3B, cosiderably longer than I remembered when doing this on an Intel (okay an I7) platform. I did manage to get the APRS iGate working (holy deja vu), and also managed to get the wspr monitoring going. I did have to run rtl_test for "calibration"
0: Realtek, RTL2838UHIDIR, SN: 00001090
1: Nooelec, NESDR SMArt v5, SN: 00000001
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Supported gain values (29): 0.0 0.9 1.4 2.7 ...
[R82XX] PLL not locked!
Sampling at 2048000 S/s.
Result: An aprsmon.sh script that runs rtl_fm on the 2M APRS frequency (144.390), piping the output into direwolf which captures and submits the APRS details to aprs.fi. The aprsmon.sh script is using the first (my original) rtlsdr dongle and rtl_test sowed no ppm adjustment was needed. The second script, wsprmon.sh uses the new rtlsdr dongle, the NESDR, and is running rtlsdr_wsprd on 2M and I did enter a ppm adjustment of "2" as indicated by rtl_test.
As far as I can tell, there isn't a lot of traffic outside of APRS on 2M to pick up. The hub *is* up and running for now, so I'll let it run for a bit.
2023-02-19 Protest on 10 meters
I'm just reporting the news here, not making it. This scrolled by on my WSJT-X FT8 screen this morning.
133000 -3 0.2 601 ~ BD7BM ND4Q -08
133000 -1 0.1 1956 ~ WB1FWS WA8SHC EN91
133000 -10 0.2 1696 ~ K3RAW KE2EF 73
133000 -2 0.1 1800 ~ BD3GIP W4VIK EN71
133000 -6 0.3 2362 ~ CQ W4SXZ EM75
133000 -8 0.2 1421 ~ K0FRY KA0HMO EN34
133000 -6 1.7 839 ~ KK6MYO N4QEP EM60
133000 -11 0.2 1105 ~ CQ DX KD9BZD EN90
133000 -14 0.6 2797 ~ <...> AA7EW -09
133000 -14 0.3 930 ~ N0PAA KB4VL EM75
133000 -18 0.2 1607 ~ RUS STOP WAR133000 -17 1.0 2023 ~ CQ K8USN EM90
2023-02-18 SDR radio - software setup 2
(1) Build and compile the rtl_tools suite (primarily rtl_fm).
(2) Install soapysdr.
(3) Build and compile the rtlsdr_wsprd application.
(4) Get and install Pulseadio, Pavucontrol, Mplayer etc.
(5) Build and install csdr, nmap, chrony (adjust clock).
(6) Build and install Direwolf.
2023-02-15 SDR radio - software setup 1
I had started documenting the build of a monitoring setup using equipment I already had on hand for the most part. I was going to use an SDR dongle, an old Raspberry Pi 3B, and some web SDR software to get this going. I've already talked about the change in direction due to the software. I was initially trying to get a public-access web SDR interface running primarily because there doesn't appear to be anything on Long Island and almost nothing in the New York metro area. The new objective is to get the beacon monitor running as a Long Island monitoring station and NOT worry about making the access public.
(1) Implement VHF APRS monitoring.
(2) Implement 2m and 6m SSB WSPR monitoring.
(3) As a stretch goal, implement additional digital monitoring modes on 10m.
2023-02-10 SDR radio hardware setup 3
After spending a few days on this without much progress, I have decided that the major non-performer in this setup is Openwebrx itself. So my software approach to this has undertaken a large pivot in direction. I have re-installed the Raspbian image, as the Openwebrx image had no desktop environment and generated numerous errors when I tried to install and enable the desktop.
Even though I was running the hardware "headless" a lot of the SDR tools (and certainly audio components) required a desktop environment for configuration and in many cases (GQRX, WSJT-X), for execution so starting with a fresh plain Raspbian image made the most sense
2023-02-08 SDR radio hardware setup 2
I know the attic receives signals because my earlier Baofeng based iGate with its stubby OEM antenna and later, the Abree antenna picked up APRS signals - the problem was there were not a whole lot of signals to pickup.
If I key up one of the HT's within a monitored VHF range I can see the waterfall and hear (low signal though) my own voice, so the Nesdr and ham-it-up upconverter (connected in passthrough mode) was working. I also hooked up the original RTL-SDR dongle as well to a 2M dipole and that also worked in picking up broadcast FM, my own HT generated APRS messages, and messages from 2 or 3 relativly local iGates. Since then, I've picked up nothing (other than these) on either SDR dongle for 2M or 6M APRS traffic.
I'm going to just let the setup run for awhile on its own - do some research and come back to it as it may be just my not configuring things correctly but I have a sneaking suspicion that I just need a better SDR radio AND there's not a lot of traffic to hear.
2023-02-06 SDR radio hardware setup 1
I have the Discone antenna and a 6M dipole mounted in the attic. I connected the Discone to the NESDR and at a later time the 6M dipole antenna. So far, I am not very impressed with the SDR radios. I know that the attic is not the best location for antennas but the SDR's are picking up nothing outside of the normal FM broadcast stations.
2023-02-05 The uSDX+ radio and a return to cw
I received a reminder from LICW that my year membership was about to expire. Time goes by when you're having fun, and I guess I had more intention to learn CW than actual sit-down practice and learning time to do it. Anyway, I renewed as a lifetime member, and with the best intentions and all that, I will start back at the beginner level this week. This is why I wanted to get the uSDX+ working, as it has a CW practice mode and what looks like a built-in CW decoder. I hope the CW practice mode and my (new) paddle will sound a LOT better than the MFJ-557. I will still use the MFJ-557 just as a regular straight key, as the LICW recommendation is to use a straight key while learning how to send.
The uSDX+, the real one, and my (presumably Chinese clone) support CW and CW keys and paddles out-of-the-box.
2.1 CW Decoder: Enable/disable CW Decoder (ON, OFF)
2.2 CW Tone: CW Filter+Side-tone (600, 700)
2.4 Semi QSK On TX silents RX on CW sign and word spaces
2.5 Keyer speed: CW Keyer speed in Paris-WPM (1..35)
2.6 Keyer mode: Type of keyer (Iambic-A, -B, Straight)
2.7 Keyer swap: to swap keyer DIH, DAH inputs (ON, OFF)
2.8 Practice to disable TX for practice purposes (ON, OFF)
3.1 VOX Voice Operated Xmit (ON, OFF)
10.1 Backlight Display backlight (ON, OFF)
As you can see from the above menu items, CW is well supported (don't yet know about the implementation) and that MENU 2.8 item is the main one that I am interested in. I will also connect a dummy load to the antenna connector to be belt-and-suspender safe while practicing.
The CW decoder may be icing on the HF cake if it works. For a little over $100, this may be a CW learner's best life I'll let you know, of course, so stay tuned.
2023-02-04 The uSDX+ (micro sdx plus) hf radio revisited
I picked this radio up on a whim since it was only $100. Walt, K4OGO, on his Coastal Waves and Wires Youtube channel, said the radio was not too bad and figured I could take it with me on a trip to Washington without worrying if it broke or got lost.
I didn't get to use it in D.C, but at some point between charging it for use then, until earlier this week (yes, mine has the internal battery), I thought I had lost the charger.
I could not find **any** reference online to what the charger is, so I am posting a picture of the charger information here to help out anyone else that needs one. It was nice to plug the DC connector into the radio and see the bright green LED light up before I even plugged the charger into the AC outlet.
2023-02-02 Software Defined Radio - operation
I now have the Openwebrx Raspberry Pi back in the container, in my attic, alongside my hotspot and clearnode. The Openwebrx is connected to the same powered usb hub. I initially connected Openwebrx to the Youloop mounted in my attic, but signal reception on 2M, 70cm, 40m and 20m was not very good. In fact, only Broadcast FM came in clearly. I then installed a a dipoile made of split speaker wire and connected with the balun that came with the Nooelec. Again reception was about the same (i.e not much). I should note that I did pickup a test transmission from one of my handheld HT's on both 2m and 70cm so the SDR setup does work. My next attempt will be to test with an attic mounted Discone antenna which I just ordered and maybe also test with my known working, outdoor end-fed half wave antenna.
2023-02-01 Software Defined Radio - software
I tested several open-source SDR packages on my laptop, primarily running SDR++, CubiC SDR, and SDR Sharp to check out the SDR and the antenna.
My priorities for getting everything running were:(1.) Access to the SDR remotely, not directly attached to my PC/Tablet/phone. (2.) Remote access via a web browser and NOT through a thin client application that needs to be installed. (3.) Some kind of API to manage the device for authorized users.
I want to run the application on my local network but also want the ability to open the application up (indirectly) on the internet. This ultimately means some type of web proxy on a cloud platform connecting to the backend SDR on my home network. There were not many choices if you did not want to be tied to using a specific SDR device, so I went with Openwebrx.
I installed Openwebrx (“sudo apt-get install openwebrx”) with the Raspberry Pi image. The only “gotcha” with that installation was that after I had it installed and running, I could not SSH into the device because I had no access id and password the standard “pi” user and password did not exist. The “trick” that other Openwebrx installation guides had missed is that you now have to use the raspberry pi imager to write the image to the SD card and to specify an id and password when writing the image. You can’t use your usual tools (Balena Etcher, in my case) to create the image. I installed rtl-sdr to get the sdr tools (**“sudo apt-get install rtl-sdr”**) and soapysdr (updated sdr drivers):
pi@openwebrx:~ $ SoapySDRUtil --find
Soapy SDR -- the SDR abstraction library...
[INFO\] [UHD\] linux; GNU C++ version 10.2.0; Boost_107100; UHD_126.96.36.199-4
Detached kernel driver
Found Rafael Micro R820T tuner
Reattached kernel driver
Found device 0
default_input = True
default_output = True
device_id = 0
driver = audio
label = PulseAudio
Found device 1
driver = radioberry
Found device 2
available = Yes
driver = rtlsdr
label = Generic RTL2832U OEM :: 00000001
manufacturer = Nooelec
product = NESDR SMArt v5
rtl = 0
serial = 00000001
tuner = Rafael Micro R820T
I decided that I might as well run my original DVB dongle alongside the new Nooelec dongle. Unfortunately BOTH devices were given serial number "00000001". Fortunately, I was able to change the serial number of the DVB SDR dongle ("sudo rtl_eeprom -s 00001090")
and that was it.