W8EMV - Whiskey Eight Echo Mike Victor

Operating notes: new net protocol for Washtenaw ARPSC net

Our ARPSC (Skywarn) net switched to a new check-in protocol on the Sunday night net. Rather than giving your entire info all in one go, you check in with just a call sign, and then net control calls a roster.

This makes the net more of a directed net, and spends less time on calls that double. It also means that net control has more than one opportunity to correct a missed call sign.

Never one to miss an opportunity to innovate, I'm going to try this approach on a big zoom call, one where it's always uncertain who goes next.

See https://mastodon.radio/@w8emv/104703215788181316 for discussion.

Fine business! Moving to Twitter handle @W8EMV

I'm switching around my Twitter setup so that my main account is now @W8EMV. The goal is for everything in that stream to be on topic, with two acceptable topics of radio (ham radio, shortwave and AM DX listening, SDRs, whatever) and work (open source ecosystem development at Packet, an Equinix company).

With any luck the narrowing of focus will result in a more manageable stream. Every post should include the word "radio" or "open source" in some measure, or reference the same.

My old account still exists but it's protected. As the Green Bay Packers once said, "Fresh Start with Bart". It was too much work to even comprehend how to deal with 60,000+ tweets.

Twitter is problematic for many reasons, so I'm trying to only reopen a narrow channel to it.

What is the effective coverage of my DMR hotspot?

My new MMDVM DMR hotspot shipped with a little SMA antenna, and has a power output measured in milliwatts. I wanted to figure out just what kind of effective range I had for it, so that I could get away from my desk while connected to it.

My radio is a DM-5R with low power at 1 watt and high power at 5 watts. At about a block away from home, transmitting on low power, I can get a clear echo reply to my hotspot with Parrot. At four blocks away, the low power TX doesn't get into the hotspot, but my RD-5R still picks up some fraction of activity on an active channel.

The next test was to change to high power (5 watts) on the radio, and to get a better antenna setup for the hotspot. I have a 2 meter ladder line antenna that also works on 440, so I connected that up to the SMA port to see how it would work. My best distance was about 137 meters, as measured by GPS, from my house to the bus stop. That's almost line of sight with just one building in the way using high power (5 watts) on the RD-5R into the hotspot, and Parrot to verify transmissions.

Some other DMR range experiments from Youtube:

• K0LWC measured 0.7 miles (1100 meters) with an Anytone 878 into a 10 milliwatt hotspot, with clear line of sight across a park and no buildings obstructing his view.
• KG4VDZ hooked up a SharkRF OpenSpot 20 milliwatt hotspot to a 50 watt amplifier, and claims a DMR range of 15 miles using a vertical antenna on top of a tower.

Prop Shop on WCBN-FM, Saturdays 900p - midnight

DJ Chill Will hosts The Prop Shop, a long-running hip-hop show on WCBN-FM 88.3 Ann Arbor. Check out his Mixcloud as "DJ Chill Will 734".

Feditalk QSO (DMR, Brandmeister TG 23514) with M0YNG

Proof of work - photo courtesy Christopher M0YNG, showing his newly acquired display screen for his MMDVM hotspot.

This was unplanned! I happened to have the radio on as M0YNG was tuning up. We had a good 10 minutes chat about radios, tech in general, and how hard it can be to find the instructions to do anything technological because of the vast amounts of jargon in use across the board.

dmrconfig - a configuration utility for DMR radios

I have a Radioddity / Baofeng RD-5R DMR radio. I got it back in 2018, and have recently added an MMDVM hotspot for it to my collection.

One of the downsides of programming this particular radio is that CHIRP (which is used to program analog radios) is not available for DMR, and that the supported radio software only runs on Windows. And while Windows is fine, the rig I have to run that at home is an ancient Eee PC with a small screen that makes using the programming software awkward at best.

An alternative to the vendor software is dmrconfig, a configuration utility for DMR radios by Serge KK6ABQ. It supports a pretty good set of DMR radios including my RD-5R, and it runs on MacOS and on Linux. It lets you read and write codeplugs to the radio, and it helpfully converts your codeplug to a human readable file so that you can edit it in a text editor.

So far so good with dmrconfig - I've only used it once, but the programming looks like it took just fine. It's certainly a lot more helpful to have a format that can be backed up easily! It does however make me want to get a radio that can have more user entries in the database, the RD-5R is skimpy on that account.

Also noted but not tried yet: qdmr, which uses the same codebase as dmrconfig for radio codeplug writing but that offers a GUI for it. Worth a test another day.

Thanks to @[email protected] for the reference to dmrconfig - they are using an Anytone 878 radio with this particular setup.

Radioddity RD-5R "RX Group List" - or, why can you hear me and I can't hear you?

A programming quirk of the Radioddity RD-5R.

If you want to add a DMR talkgroup to talk on, there are really four things you need to do:

1. Add a digital contact, listing call ID and name.
2. Add a channel, listing that contact along with frequencies.
3. Add that channel to a zone, allowing you to select it on the radio.
4. Add the channel to the "Rx Group List" so that you can listen to it.

If you miss step 4, you get the following: people can hear you on a channel, but you can't hear them.

Debugging this was tricky. I had added a few extra talkgroups to my hotspot configuration, so I thought I had checked everything - and it turns out I had everything correct for transmitting. What could be different about the Feditalk group? Well, it's UK based, so I tried connecting to the UK Brandmeister server and listening to some other UK talkgroups, and that didn't work.

The AHA moment was of course an RTFM situation. Section 3 of the Radioddity DMR Quick Start Guide referenced a screen I hadn't seen before, the "RX Group List". Adding the channels to that list (and noticing that they weren't there already) fixed the problem.

Thanks to the following for helping me through this bit of troubleshooting:

• Nick W8XM for the ARROW RD-5R codeplug and some timely consulting on RX offset programming
• Patrick KC3OWU for encouragement and debug help and a first successful QSO on Feditalk, TG 23514
• Christopher M0YNG for running mastodon.radio and prompting this exercise in the first place

Having figured all this out, I'm now intrigued by OpenGD77 which is open source firmware for this RD-5R radio and for other DMR radios. Perhaps a next project!

New gear: MMDVM hotspot from Radioddity

New radio! This one is an MMDVM hotspot assembled for and sold by Radioddity. The part I got is clearly labelled "Made in China", but it was shipped promptly from the Radioddity depot in Las Vegas, Nevada. It arrived in a small cardboard box with a single page of tutorial instructions and a few extra screws.

The tutorial text is "Geek Teches THE MMDVM DMR TUTORIAL". I'm certain that it reads better in whatever language it was originally written in, and frankly the text is confusing at best. Fortunately the software and hardware is an ordinary MMDVM and Pi-Star configuration, and there's plenty of good tutorials for that.

Some useful tutorials include:

• Playing with Pi-Star, Amateur Radio Notes, Toshen KE0FHS
• Pi-Star Digital Voice Software, Pi-Star. Official docs
• Pi-Star integration with Brandmeister API, Brandmeister wiki

Nick W8XM was very helpful - I happened to catch him on the ARROW 2m FM repeater while I was putting things together, and I related the problem I had originally where people could hear me but I could not hear their return. It seems that the hardware in this kit is subject to frequency drift, and you need to tune the "RX Offset" with some trial and error (using Parrot) to get an accceptably low BER. At zero offset I had 1.3% error rate; after tuning to -200 my BER was down to 0.2%. Ailunce has a good description of what you need to get to.

I had one glitch on setup - typing in the wrong wifi SSID for our home network! - and had to manually add a new wpa_supplicant.conf file to the SD card to make it work. Fortunately, this tutorial from KE0FHS made that quick work.

The Brandmeister network does not like hear lots of short transmissions in sequence from a single station, so if you are testing things out vigorously and punching a lot of buttons in short sequence you might get a user blocked voice message from the network. This corrected itself for me by waiting an hour.

With all of that set up, I'm back on the air with DMR. There's a weekly Michigan net via Michigan One DMR, and the Brandmeister Feditalk talkgroup is one I hope to make more contacts on.

73 de Ed W8EMV

WCBN-FM slowly returning to live broadcasts

As a consequence of the pandemic, WCBN-FM 88.3 Ann Arbor reverted to playing reruns of its previously recorded shows, with a station ID at the top of the hour and ever hour playing one of a variety of "Wash Your Hands" PSAs.

Live remotes are slowly returning to WCBN as the station comes up with more and more shows that can be originated off-site. A partial list follows as of the June 21, 2020 schedule.

• Monday 2:00 p.m.: Y against X with RC
• Tuesday 6:30 p.m.: Interactive Technlogies with Pan
• Tuesday 7:00 p.m.: Train to Skaville with Brian Tomsic
• Tuesday 8:00 p.m.: Go Kat Go! with Del
• Wednesday 11:00 p.m.: Freeform with Herb
• Thursday 3:00 p.m.: Freeform with TeacherPatti
• Thursday 7:00 p.m.: Face the Music (rerun) with Arwulf
• Thursday 10:00 p.m.: Crush Collision
• Friday midnight: Undefined Behavior
• Saturday 7:00 p.m.: Dance Hall Reggae with Brian Tomsic
• Saturday 9:00 p.m.: Prop Shop with DJ Chill Will
• Sunday noon: Mediterranean Diet
• Sunday 3:00 p.m.: Sounds of the Subcontinent
• Sunday 4:00 p.m.: Pan-African Heartbeat
• Sunday 7:00 p.m.: Waves with DJ Jojo

All programming subject to change, contact the WCBN website at W W W dot W C B N dot ORG for details.

We'll get through this, as long as we all continue to give...Power to the Transmitter!

Field Day 2020 rules changes

Field Day is an annual event for amateur radio clubs around the country. The 2020 Field Day (June 27-28) will be different this year during the pandemic, and the ARRL has issued new rules that expand the role of home stations ("Class D", running on commercial power) in counting towards club goals.

Some local commentary on these changes is from Dan KB6NU who plans to operate Class 1B (battery powered) from his back deck.

As for me, I've already had a few QSOs on 2 meter simplex from my handheld from my home QTH and look forward to hearing some activity on the 2 meter band and the 70 cm band for that.