W8EMV - Whiskey Eight Echo Mike Victor

Skywarn Recognition Day on Saturday, 3 December 2022 0000z-2400z

The National Weather Service has announced that Skywarn Recognition Day 2022 is Saturday, 3 December 2022. Trained Skywarn spotters are encouraged to register on the event web site and check in for their location, get assigned an SRD for contact exchanges, and upload their contact logs to the NWS after the day. The hashtag of the day is #skywarn2022 but I have also seen #skywarn22 and just #skywarn .

ARRL has SKYWARN Recognition Day Operating Instructions. Participating stations are asked to exchange QSO information with National Weather Service stations from 0000z-2400z (700p Friday night to 700p Saturday night, US Eastern time). The exchange is Call sign, signal report, QTH, and a one or two word description of the weather occurring at your site ("sunny", "partly cloudy", "windy", etc.). (e.g. W8EMV 59 Ann Arbor windy). If you register with the NWS ahead of time you can get an SRD number - mine is SRD-DTX-1226. NWS stations will work various modes including SSB, FM, AM, RTTY, CW, and PSK31. Contacts via repeaters are permitted.

Locally here in Ann Arbor, the Skywarn repeater for Washtenaw County is the N8DUY repeater on 145.15- PL100.

The current Hazardous Weather Outlook for the Detroit/Pontiac DTX region is a wind advisory tonight through Saturday morning for wind gusts of 40 to 50 mph.

On the net, two Mastodon servers of interest are mastodon.radio and wx.social. The first is of special interest to ham radio operators, and the second is a new system for weather and weather adjacent (climatology, geography) enthusiasts, professionals, and students from the good folks at StormDig.

I plan to be tuned to N8DUY locally, and hope to pick up some DMR contacts along the way. I'll be checking the Fedihams network as well.

The map of the Maine Skywarn network for station WX1GYX Gray, ME lists TG 759 (SKY) on the DMR-MARC network for "SKYWARN for ME & NH". The Brandmeister DMR network lists TG 31206 as the "Central Kansas Skywarn" channel; please note these are not rag chewing talk groups .

Quartz crystal controlled radios in World War II

Some notes on the World War II supply and demand for quartz crystals for precise radio frequency control, in preparation for reading "Crystal clear : the struggle for reliable communications technology in World War II" by Richard J. Thompson, Jr. (Wiley, 2007). I have the book on its way on inter-library loan from MeL, via the Ann Arbor District Library.

https://www.wiley.com/en-us/Crystal+Clear%3A+The+Struggle+for+Reliable+Communications+Technology+in+World+War+II-p-9781118104644

The table of contents from the book:

Introduction : "We were heavily armed, and we had crystals" -- From wire to wireless : the development-- and acceptance-- of tactical radio -- Crystal control-- the great gamble -- The Signal Corps lays the foundation -- Nothing else to do but grind crystals -- Riding the "Flat Wheel Limited"-- overseeing a mass production industry -- Supplying a mass production industry-- the civilian government steps in -- "The whole radio crystal program of the Armed Services depends upon the success of the procurement program in Brazil. Nothing must be allowed to interfere with it" -- "God made lots of small crystals" -- The aging crisis-- stopgap measures -- The aging crisis-- physics to the rescue! -- "Without crystals, you have radio; with them, communications" -- Appendix 1 : Crystal-controlled equipment -- Appendix 2 : Crystal manufacturers.

The US Army's history of the Signal Corps is told in "The Signal Corps: The Outcome". Chapter 3, "The Signal Corps in the ETO to Mid-1944", has this to say about the use and preparation of the crystals themselves at p.89:

https://history.army.mil/html/reference/Normandy/TS/SC/SC3.htm

Over the strenuous objection of General Vulliamy and the signal staff, the committee took frequencies from the ground forces and reduced the already narrow separation of channels in the 1- to 5-megacycle band from five kilocycles to four. That meant grinding more crystals, and on extremely short notice, for it was 10 May when the revised frequency allocation list was issued. But in this specialty the Signal Corps had become proficient, even to the point where what had once been a most exacting laboratory technique was now transported into the field, and mobile crystal grinding teams were at hand. The task of providing crystals by the thousands, meticulously prepared, emphasized the one drawback to their use. Nevertheless, the American decision to use crystal-controlled mobile FM radio greatly simplified the job of frequency control in the jam-packed spectrum of sky over Europe from D-day on.

Where did these crystals come from? Before the era of lab-grown quartz, the predominant supplier of suitable quartz crystals comes from a few large quartz mines in Brazil. A 1943 US Information Agency short, "Brazilian Quartz Goes To War", is available from an exhibit at the University of Indiana.

https://collections.libraries.indiana.edu/IULMIA/exhibits/show/world-war-ii-propaganda-films/item/1450

The value of Brazilian quartz to the allied war effort is shown as narration proclaims "two-way radio is the one really new instrument in the armory of warfare." Explains the value of quartz in radio communication, showing how a wafer of its crystal makes possible the simultaneous broadcasting of many stations without overlapping. The film emphasizes the necessity for international cooperation in the war effort.

After the war, the supply of war surplus crystals entered the ham radio market. Dennis Monticelli, a Fellow at National Semiconductor, tells the story in an article in EDN.

https://www.edn.com/crystal-grinding-when-electronics-were-really-hands-on/

During WWII crystal making took a leap forward in the US and turned into a big cottage industry supplying the wartime needs. There is a wonderful new book out on that subject that goes through the history and basically makes a “how we won the war” claim. Following the end of hostilities, the cottage industry collapsed and huge numbers of used and NOS crystals in screwed together non-hermetic holders flooded the market. Hams began grinding again and didn’t have to move the freq as much as before because the selection of starting material was huge. Hams could then use mild abrasives like comet or even milder like toothpaste powder. Today you could use wet silicon carbide sandpaper if you wished. I actually succeeded at etching them to freq using a very dilute HF solution when I was 15 and didn’t know how dangerous HF acid was.

You will still hear radio amateurs who talk too long on a local 2 meter repeater to the point that the repeater times out refer to this as winning the "purple crystal award". I wasn't able to pin down any origin story for this phrase, or even to know if this is a regional Michigan thing or in common global use.

updates

A few bits of additional information:

IEEE TV: Richard J. Thompson. A 9 minute 2007 interview with Richard J. Thompson, author of "Crystal Clear".

A brief history of quartz crystals and their aging problem, Planet Analog. A 2021 discussion of how quartz crystals fail and drift due to aging from cracks and microparticles, a problem solved by smoothing the surface with acid etching.

Crystals Go To War, US Army Signal Corps, digitized by Reeves Sound Laboratories for the Prelinger Collection at the Internet Archive. 1943. "A story in pictures of the preparation and manufacture of quartz crystals for radio communication."

second updates

Thanks to Jacek KW4EP.

Quartz Crystal Growing, Western Electric / Bell Telephone Labs / AT&T Archives, 1962. A video showing postwar innovation in synthetic crystal growing technology, using a high temperature, high pressure vessel to dissolve and then redeposit quartz onto precision cut seed plates for crystal growth.

UFFC-S History, IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society. The "frequency control" portion of this professional society's archives include records from the 1944 Crystal Conferences. "This period was one of considerable growth, both in the quantity of crystal units produced and in advancing the art in crystal theory, design, and manufacturing. There were approximately 15 companies before the war who were making, at most, 100,000 crystals per year. During the war, this number grew to about 115 companies and 30 million crystals per year."

FediHams, a multiprotocol digital voice interconnect from DK1MI for Mastodon and the Fediverse

FediHams is a digital voice interconnection with support for multiple ham radio networks, put together by Michael DK1MI to support amateur radio use and experimentation for the Mastodon network.

For more info about FediHams and instructions on how to join, see its home page at https://fedihams.net . For details about Mastodon.radio - one participant in a federated set of servers sometimes known as the Fediverse - see https://mastodon.radio .

The network as it's currently constructed allows use by amateurs coming in on the Echolink, Allstar, Yaesu System Fusion, and Peanut networks, as well as to two different DMR networks (Brandmeister and TGIF). All of these nets require proof of amateur status to join. Not all of them require a purpose built hardware radio to connect; in particular, Echolink and Peanut were both tested with apps running on my Android mobile phone.

I connected to the FediHams network with three different configurations - Echolink (via phone), Peanut (via phone), and DMR (Brandmeister DMR via a DMR radio and my MMDVM gateway).

For Echolink, the configuration was easy because I already had the software running on my phone to support connections to the regular Sunday night net run by the University of Michigan Amateur Radio Club. Use node DK1MI-L (963110) and you'll be added to FediHams. Please note, the Echolink use of Internet protocols doesn't always play nicely with modern firewalls, and I nearly always have to turn off wifi and connect through the data plan on my phone; your results may vary. If you don't already have Echolink installed, after you download it you'll need to validate your license via instructions at https://www.echolink.org/validation/ .

For Peanut, you'll want to download a client from the home base of David PA7LIM at https://www.pa7lim.nl/peanut/ and send in your proof of license via provided instructions. The software is provided for Windows (not tested) and Android. Once that is all set (it took a day for me), you can configure the app to connect to the channel of your choice and away you go. Please note that channel listings are provided via a drop-down menu keyed by country, and the YSF-FEDI channel is listed under the DE (Germany) menu. The user interface is a simple push-to-talk, and I found the sound quality quite pleasant especially because I could use a good headset on my phone.

I'm using the Brandmeister DMR network on my MMDVM hotspot, and a Radioddity GD-77 HT. Program your HT to connect to TG 2630002, and then check the Brandmeister network info page at https://brandmeister.network/?page=lh&DestinationID=2630002 to see your traffic. On my MMDVM hotspot status page, the connection shows up as TG DK1MI. MMDVM will start monitoring FediHams once your first transmission goes through. If you want to always have traffic to FediHams key up your radio, you'll need to connect to the Brandmeister "Self Care" page for your hotspot and add 2630002 as a static talkgroup.

My first test on FediHams was to use Echolink and DMR to both connect to the network at the same time and to talk to myself. Sound quality was fine, and the delay in transmission was about 4-5 seconds. (Delays come from the distance of the Internet connection from Ann Arbor to SW Germany, but also from delays associated with voice transcoding.) I even had a pretty respectable echo loop set up as the phone and the radio listened to each other.

More fun of course is an actual QSO with an actual person on the other end of the line. Michael DK1MI and I had a few nice conversations on 2022-10-11 - one part "how do I sound" of course, and also a discussion of how the network is put together and some hopes for future use. DK1MI has a blog at http://qrz.is which has details on a number of projects (hardware and software) with a ham radio theme.

This is my second go at getting a useful repeater configuration for use with Mastodon.radio. You can see my notes on the first try at https://vielmetti.typepad.com/w8emv/2020/07/feditalk-qso-dmr-brandmeister-tg-23514-with-m0yng.html where Christopher M0YNG and I both made a connection through a Brandmeister DMR TG. My hope is that the new FediHams setup will work with connections from a variety of networks and will also help discover new connections.

73!

Listening to Florida Hurricane Ian traffic via SARnet and HWN

SARnet is a linked UHF repeater network with coverage throughout the state of Florida. Keying up one local repeater brings up every repeater throughout the state, and so it's useful and used for wide area coverage for weather situations like Hurricane Ian which as of this writing is heading for the Tampa, Florida area.

Traffic so far has included readings of National Weather Service forecasts for Hurricane Ian, as well as tornado warnings for areas affected by the outer bands of the storm.

Get more information about the operations of the network at http://www.sarnetfl.com, and listen to a feed via Broadcastify at https://www.broadcastify.com/listen/feed/35392 The stream is monitored by KO4EFS on the Lee County NX4Y Repeater in North Fort Myers, Florida on 444.225Mhz.

Hurricane Watch Net is held on HF on 14325 MHz and 7268 MHz. The associated web site, https://www.hwn.org , has current information about hurricane and tropical storms using information out of the National Hurricane Center in Miami, Florida. Monitor these frequencies via your favorite KiwiSDR receiver, or through WebSDR receivers at NA5B in the Washington, DC area at http://na5b.com:8901, or through your own HF receiver.

Remote access to GQRX and an Airspy HF+ SDR on an old MacBook Air

A description of my current remote listening post, which lets me tune over quite a range and listen to radio through my laptop from wherever I am to a home receiver.

The computer is a 2014 MacBook Air running MacOS, which I bought new and which was a daily driver for quite some time. The power cable gave out at one point so I replaced that, but otherwise it's been quite reliable. It's not fast enough to handle a modern workload of dozens of tabs open in a browser, but it's plenty fast to be an SDR front end.

The SDR software is GQRX 2.15.9 from https://gqrx.dk , downloaded via Homebrew. This is an open source tool from Alexandru OZ9AEC with support for Linux and Mac, using GNU Radio for processing, the Qt toolkit for a user interface, and the gr-osmosdr library for SDR support. Like any good usable SDR it decodes AM, FM, and SSB. Helpfully for my task it can also relay an audio feed over UDP.

The SDR hardware is an Airspy HF+ Discovery SDR, paired with a Youloop antenna, purchased from Airspy.US last year. This setup covers 0.5 kHz to 31 MHz plus 60 to 260 MHz, i.e. broadcast AM and FM, 2 meter VHF, air band, HF and shortwave bands. The Youloop is hanging from a curtain rod - I have not yet done anything fancy to try to tweak positioning for best reception.

All that plugs together pretty nicely, but it's all plugged into an old laptop that's tethered to a power cord, and as such that doesn't do so well for listening to radio around the house. So I have a few more pieces in place to enable remote tuning and remote listening from my M1 MacBook Air that's my new daily driver, either around the house or wherever.

The first bit of the remote access puzzle has been to install Tailscale everywhere I ever need to use a computer. This VPN software lets you put together a private network of machines that can talk to each other over an encrypted (Wireguard) connection. Tailscale takes care of poking holes through firewalls so you can put endpoints anywhere - around the house, at the office, in the cloud. It also has DNS support that gives systems meaningful names so you don't have to memorize IP addresses.

With that in place, the remote access piece is provided by the built-in MacOS program called "Screen Sharing". This software (based on VNC) lets you remote in from one Mac to another. I found that it handles keyboard and mouse events really well, but surprisingly doesn't have any options for sharing sound coming off of the machine. A quick look at general purpose sound sharing options got very complicated very fast, so I stopped looking.

What got me going again was curiosity about the "UDP" button in the "Receiver options" menu of GQRX. It turns out that for some time now, GQRX can stream audio to a local (or a remote) UDP socket. This is helpful for interfacing local audio data decoding or analysis tools on the same machine (e.g. setting up an image decoder to display SSTV images), but it also can be used to stream audio over the network.

The final piece is software to catch that audio stream, which I already had installed. The venerable VLC tool lets you point at a UDP stream and pick audio samples off the wire for playback. The tutorial on streaming audio over UDP has everything you need, including this magic incantation for starting up VLC with all the right configuration options:

vlc --demux=rawaud --rawaud-channels=1 --rawaud-samplerate=48000 udp://@:7355

The end result is a remote radio in a window with a waterfall display and a reasonably responsive audio stream. Thanks to Tailscale you can take this combination anywhere and it will still work, though if your network is slow or lossy there will be lag or dropouts.

Some alternative options if you don't have the exact combo of things that I have.

GQRX runs on old and new Macs, as well as on Linux systems like the Raspberry Pi. A Pi 4 has plenty of oomph to decode a signal, and there are videos of people building Pi 3 based systems using a lower FFT size and rate.

If you do run this with a Pi as a remote, you'll still use VNC as the screen sharing protocol. RealVNC has a "VNC Server" for Raspbian, and there are indications that this is easy from a Mac using the built-in "Screen Sharing" client. I have not tried this myself.

GQRX is not the only SDR software out there! If your remote machine is a Windows machine, and if you have figured out how to remote into it, then SDR# (SDRSharp) is an excellent tool with lots of signal processing capabilities and a plugin (sdr-UDPAudio) to let you stream audio as UDP. My old Windows on Arm machine didn't have an obvious way to remote into it, so sorting out these details is up to you.

There's other SDR hardware out there! I got my start with an inexpensive RTL-SDR tuner stick which uses repurposed European DVB-T television hardware (RTL2832 + R820T) to pick up signals. Spend $25-$30 for a nice RTL tuner at Nooelec or RTL-SDR.com, or take your chances and spend about half that for a similar part of unknown quality from AliExpress. The RTL based hardware has a smaller frequency range, so you won't get AM or HF or shortwave reception, but you will pick up 2 meter ham band and broadcast FM even with the inexpensive antennas that come in these kits.

If you want to listen to SDR and don't have any hardware at all, try the KiwiSDR or WebSDR networks. WebSDR supports dozens or hundreds of simultaneous listeners at each of a few listening posts scattered throughout the world. The KiwiSDR network only handles 1-8 listeners per location, but there are hundreds of these receivers out there in dozens of countries.

Successful reception of German DRM shortwave student radio station "Funklust" via KiwiSDR Vilradio

Funklust is a German student radio station from Uni FAU that broadcasts online and via shortwave radio. The shortwave signal is 24/7 on 15785 kHz from a transmitter in Erlangen, Germany. I was able to tune in via a KiwiSDR receiver Vilradio nearby, the above screen capture shows the settings to turn on DRM reception.

RedTech has a May 2022 story, Funklust is back on air with a boost, which describes their new transmitter, "a new RFmondial 250 watt transmitter, which feeds the signal into a vertical lambda/four-monopole antenna mounted on a concrete mast at a height of 58 meters". The story describes how the students handle the programming for the station, and the nearby Fraunhofer Institute for Integrated Circuits handles the technology.

Additional technical details are in a blog from Fraunhofer, funklust broadcasts in DRM on shortwave. There is apparently a text-only sideband "Journaline".

I'm a fan of college radio in general, and the Funklust programming that I've heard to date has been a great stream of music that I have not heard elsewhere. Worth a listen.

2022 software defined baseball season

Previously: 2019 and 2018.

2022-04-16: The great weird idea is to put together a guide for KiwiSDR and WebSDR listeners for tuning into remote baseball games. SDRs come and go, so any guide that is too specific about exact IP addresses is probably a bad idea. However, I should be able to map AM frequencies to grid squares, and leave it up to you to tune the receiver in that particular grid (or nearby) to that frequency.

Your reception reports are welcomed.

As an example: on a good night in EN82, I can pick up the following teams and stations (and more):

• EN82 DET 1050
• EN82 CHC 670
• EN82 CHW 1000

The Dodgers have an affiliate in Hawaii, KIKI; their flagship station in Los Angeles is KLAC.

• BL10 LAD 990
• DN04 LAD 570

There's a KiwiSDR in EN61 with excellent Chicago and good Milwaukee coverage.

• EN61 CHC 670
• EN61 CHW 1000
• EN61 MIL 720

To get a full database is a whole lot of work (!) so I don't pretend that I'll get everything, but I would like to listen to every team at least once. The hardest ones in general from past seasons are the San Diego Padres and the Toronto Blue Jays. Easy are the Detroit Tigers (which I can pick up on local broadcasts on AM and FM with barely any antenna) and the Chicago Cubs and Chicago White Sox (easy at night from here over the air on AM, and several good Chicagoland SDRs).

Skywarn report: Ann Arbor Father's Day storms, 2021

On Sunday, June 20, 2021 from 8:15 pm - 11:05 pm the Washtenaw County Skywarn net was activated for a series of severe thunderstorm warnings. The net stayed in "condition green" the entire time, with WD8EOC relaying National Weather Service reports, but with no significant reports of damage in the county.

The worst of the weather passed to the south of the Ann Arbor area, with Lenawee and Monroe County seeing storm damage.

The National Weather Service summary, Severe Thunderstorms and Riga Tornado June 20, 2021, notes 50-60 mph wind, 60,000 power outages, and an EF-1 tornado in Riga in Lenawee County that had a 3 mile long track. Riga is about 45 minutes south of Ann Arbor, on US-223 west of US-23.

The area was under a severe thunderstorm watch overnight, but the most severe of the storms in that system did not make it this far east. The worst impact of the second round of storm activity was in suburban Chicago, where the EF-3 tornado from Naperville to Willow Springs blew through a 16 mile track of up to 1/3 of a mile wide that injured 11 but (miraculously) had no fatalities.

Skywarn nets in the Ann Arbor area are coordinated through the N8DUY repeater on 145.15- MHz in the 2 meter band. A slightly delayed transmission of the repeater is available on Broadcastify.

Washtenaw Skywarn net recap 2021-06-12

Steve W8AYN ran the Washtenaw Skywarn net using the WD8EOC call sign on Saturday 12 June 2021. The net started at just before 8:00 p.m. when the National Weather Service issued a severe thunderstorm warning for the county, and continued until just before 9:15 p.m when the warning was allowed to expire.

Reports from the radio and from Twitter were primarily of sporadic hail, anywhere from pea sized to quarter sized, running from Dexter to Scio Twp to southwest and west Ann Arbor. There were no high winds reported.

This storm started near Lansing and tracked to the southeast at about 20 mph. The bigger hail reports were further to the north, including reports from Laingsburg and Ovid in Shiawassee County.

More storm details from IEM.

Some useful Twitter accounts this season include

• NWS Detroit
• IEMbot DTX
• Anthony D. Torres
• Nick Dewhirst

plus the usual Ann Arbor weather chatter, which mostly discusses the famed Ann Arbor Weather Shield.

recordings of the BBC from the WebSDR at U Twente

Here's a few clips on Soundcloud from the BBC.

BBC World Service news on 7 January 2021, a minute from a shortwave broadcast with news from Washington DC. The broadcast is from 5945 KHz, a service to Asia.

BBC Radio 4 on 8 January 2021, three minutes from a longwave broadcast with an interview of Mary Trump. The broadcast is from 198 KHz, the longwave domestic service of Radio 4.

Both monitored at the U Twente WebSDR which has a handy "record" button.