W8EMV - Whiskey Eight Echo Mike Victor

Operating notes: 2 meters, 45 watts, bicycle portable with a Kenwood TK-790

This project started about seven months ago when Thom W8TAM sold me a Kenwood TK-790 radio (ex-BNSF railroad) at the Chelsea MI swap. The 790 is very sturdy and heavy and looks like it would put up a fair fight against a locomotive. The radio was already programmed by W8TAM for local Ann Arbor area repeaters, but it was otherwise bare - no power cord, no mic, no speaker, no antenna, no data cable. I put together a complete rig and hauled it to a local park on my bike to operate "bicycle portable", that is to say not operating while mobile but hauling everything on the bike.

Mobilinkd has an excellent writeup about this radio, from Rob Riggs, WX9O, Mobilinkd LLC.

http://www.mobilinkd.com/2020/07/29/the-kenwood-tk-790/

https://nbviewer.org/github/mobilinkd/KenwoodTK-x90/blob/master/Kenwood_TK-790.ipynb

I will refer you to it if you are considering acquiring one. Beware that there are a few pitfalls in getting these set up for amateur use, and some variants that are not ham-friendly. Read before proceeding.

Rob WX9O took a DIY approach to manufacturing a microphone cable, constructing a speaker interface, programming the radio etc. It's a detailed project, and he warns:

It really does not make sense to buy a TK-790, and then go out an buy all of the accessories needed to make it a functional radio.

Yet that is what I did, slowly, with the help of eBay. The power cord is Kenwood KCT-23, with power pole ends that were added at the annual ARROW meeting. The mic is a Kenwood KMC-27 from https://used-radios.com . The speaker is a Kenwood KES-4. My battery is a Bioenno BLF-1215A via Gigaparts which provides the 12A of power that this 45 watt rig wants. I'm using an N9TAX Slim Jim antenna.

First test of the whole setup is at home. With everything plugged in, the indoors antenna across the room and hanging in the window is fine. I'll look for a suitable outdoors mount for some kind of 2m antenna when the weather is warm. On the very first test I didn't have a speaker, so I used another home 2m receiver - an OpenWebRX+ setup in the attic - to tune in.

Some discussion on Mastodon - specifically on mastodon.radio - ensues about 2024 goals, and I volunteer that I want to activate a park with this rig. The multitudes encourage me, so I pack all of these parts carefully into an Ortlieb saddle bag, and head out on my bicycle to Burns Park about half a mile away early in the morning to try everything out.

What did I learn along the way:

If you wear enough layers, you can operate in the cold and damp. Bring some layers for your rig too -- I would not have wanted to turn everything on if it was actually pouring, but by strategically covering everything when it was not in use that worked out pretty well.

The Kenwood parts for this rig are kind of fiddly. The KCT-23 power cord is fine (I put new power pole ends on it) but the connector to the radio itself has the feel of old brittle plastic just waiting to snap after one too many connections. Thom W8TAM modified his rig to have the power poles right on the rig rather than at the end of a cable; that's a worthwhile change to consider.

The KMC-27 mic is also kind of fiddly. It has a weird pogo-pin connector on it, which was used only on this series of radios and none other. Parts are relatively expensive and the 3-d printed adapter from WX9O was out of scope for now. Note that the connector uses a thumb screw to make the connection secure, and I discovered that if you don't screw it in all the way you simply don't make a transmission at all.

The KES-4 speaker? Also fiddly. This has a weird 9-pin plug on it (Molex, I think) with only two pins active, and I'm wondering which time I'm going to tug on it too hard and have the plug assembly come loose. The modification that I saw involves sourcing that plug and then using the two pins to attach a little lead that has a standard mono jack on it, so that you can use ordinary speakers with this.

When I bought the N9TAX antenna, I had it built with what looks like a coat hook attached to the top. That hook was enough to wedge into a crook in a tree in Burns Park helpfully near a picnic table and operate from there. Again, for a next time: it would be useful to have another section of feed line to attach, so that I could get the antenna higher. I've also been looking at arborist throw lines as a way of getting some more elevation into trees.

It's terrific to have a weekday morning 2 meter net to test against. The crew that is on the 800a N8DUY weekday morning roundtable is always welcoming and has tolerated my bicycle mobile and pedestrian mobile testing for some time. They are always happy to hear a good strong signal, whether it's 45 watts into an antenna stuck into a tree, or 50 milliwatts from the top of a parking structure with a clear line-of-sight to the repeater. Thanks to Jim W8STX for organizing this net that's open to all licensed amateurs on 145.15- PL100 out of a repeater just to the west of Ann Arbor.

As to the radio itself, some operating notes.

I guess there's a 5 watt setting on this rig, but I used the 45 watt setting, and signal reports were excellent. It would be worthwhile figuring out how to switch between the two.

Thom W8TAM programmed in all of the Washtenaw County repeaters. I'll want to test all of those one at a time, and I'll also want to test simplex operation. No idea yet if I can do a front-panel addition of more channels.

The signal reports were excellent but my mic gain I guess is kind of low, which either means TALK LOUDER or tweak some gain setting.

Eventually I want to do digital modes on this thing, since there's a 9600 baud serial connector on a DB-25 on the back that brings out a bunch of interesting signals. How long has it been since I've built a serial cable? Again hoping to find someone who has gone before me. On the wish list: APRS, RTTY, and maybe even digital voice with M17.

It's entirely possible that most of the reason my signal reports were good was that my antenna was up a little bit and out of doors. I will be practicing with this antenna and this location and a few other radios to sort out what the best bet is.

Did I mention that this rig is built like a locomotive? That suggests that it's perhaps not the most practical approach for a bicycle (and I wouldn't want to haul it all to the top of a mountain).

Thanks to all who helped out with this adventure. In no exact order:

• W8TAM for propelling me down this path, and for sage advice
• WX9O for keeping very detailed notes on from-scratch rebuild of components
• W8STX and the weekday morning roundtable crew including N8QM, N8FPV, K8WXQ and dozens of others
• N8DUY for the use of the repeater
• the taxpayers of Washtenaw County, who help fund the repeater
• the ARROW club
• M0YNG for keeping mastodon.radio a welcoming place to nerd out about the radio hobby
• toot.bike and #BikeTooter for keeping Mastodon a welcoming place to nerd out about bicycles
• VA7BKW and K4SWL for encouragement
• N9TAX for antenna design and build
• KB6NU for an earlier antenna build session
• KD8WKU and All Hands Active for Repairsday Thursday and antenna repair
• NO5IG for antenna hoisting stories (and why real arborists don't use Baofengs as ballast)
• Sic Transit Cycles for the saddle bags
• Common Cycle for cooperative bicycle repair
• BNSF for buying - and then getting rid of - this TK-790

73 de Ed W8EMV

Operating notes: RTTY on 2 meters using DroidRTTY

RTTY ("radio teletype") is a very old digital mode. Amateur use started after World War II with surplus printing teletype units going into ham radio service. Digital modes could later be decoded in computer-controlled hardware with the AEA PK-232 - see https://www.eham.net/reviews/view-product?id=218 for some reviews on eHam. Modern software like fldigi from W8HKJ http://www.w1hkj.com decodes the tones into text using "sound card" interface into your computer.

Al K8WXQ organized a RTTY roundtable + Elmer session on Tuesday 2023-12-26 with Matt W8MAP and me (W8EMV). Al arranged for the use of the W8FSA 146.92 FM repeater. I only heard about it at the last moment - I was out and about on my bicycle and tuned in to 146.92 to hear the planning going on a few hours early - so it was good luck on my part.

The RTTY interface that I was able to put together on short notice that worked acceptably well as a start was to download the DroidRTTY application for Android from Wolphi. To use it, you hold up your phone near the handset of your favorite radio, key the mic with one hand, and transmit from the radio with the other. DroidRTTY will decode the RTTY tones, and will send messages that you select from macros or that you type in.

https://play.google.com/store/apps/details?id=com.wolphi.droidrtty&hl=en_US&gl=US

A few challenges here. You need two hands to do this, one to key the mic and one to send your message. There is a very tiny on-screen keyboard for composing messages which I don't have enough keyboard time in front of to feel like I can do an adequate job just yet. I had to select the "swap mark and space" option to be heard correctly.

An external Android keyboard of some kind looks like it would help for this.

I had also hoped to copy RTTY using OpenWebRX+ which has the option "RTTY-170 (45)" that corresponds to the 45.45 baud, 170 Hz spacing of amateur RTTY. Alas that didn't work right away and I'm looking to test it again later.

OpenWebRX+ distribution: https://github.com/luarvique/openwebrx

My receiver: https://rx.dunker-pentatonic.ts.net

More information about RTTY from the article "The origins and evolution of radio teletype", Ham Radio History, Ed Mins, W0YK

https://www.onallbands.com/ham-radio-history-the-origins-and-evolution-of-radioteletype-rtty-mode%EF%BB%BF/

OpenWebRX+ on a Pi 400 with a AirSPY HF+ SDR and Youloop antenna

My OpenWebRX+ is now up and running in a temporary setup on a Pi 400. The biggest visible change relate to OpenWebRX is a noise reduction setting and some added digital decoders. I am still exploring all of the menus. One of the things I want to do is grab SSTV images off the air - that's possible with this config but not with the old system, but no success with it yet.

https://github.com/luarvique/openwebrx

The install was pretty easy - I used their pre-baked image for the Pi 4, burned an SD card, booted it, added Tailscale as I usually do, and all was well. In the process I lost all of my OpenWebRX customizations but they were easy enough to add back in by hand. In any case I wanted to revisit some original decisions so not all was lost.

https://github.com/jketterl/openwebrx/wiki/Setup-Guide#raspberry-pi-sd-card-images

The Pi 400 is perfectly adequate for OpenWebRX+ in initial tests, but I want to move this to a Pi 4 with more open USB ports so that I can add a second RTL-SDR tuner. I have a Pi 5 on order but no particular guarantee that the whole setup will work there out of the box without at least one tweak to some component.

The AirSPY HF+ covers broadcast AM and FM, shortwave, 20-80 meters ham bands, NOAA weather radio, pirate radio on 43 meters, the 2 meter band - basically a lot of listening. The RTL-SDR would add 440 MHz and the ADS-B band at 1090 MHz. It's also the case that though the RTL-SDR has less bits of listening precision it does cover more spectrum in one go, which is handy for watching more of the band at once.

When I do an A/B comparison between my setup and the KiwiSDR nearest by ("Pembleton Farms", in Northville Township) my configuration has more noise and can't pick up signals that are as weak. I'll chalk that up to my lack of acreage to run a big 230 meter Beverage antenna!

http://misdr.proxy.kiwisdr.com:8073

Radio 48 / Mix Radio International on 6845 kHz

Listening to music on 6845 kHz (Sunday 0122 UTC / Sat 823p Eastern).

HF Underground identifies it as "Radio 48"

https://www.hfunderground.com/board/index.php/topic,121380.0.html

My signal into my Youloop / Airspy HF+ / OpenWebRX in Michigan is very noisy, time to tune some KiwiSDRs....

"Pembleton Farms" KiwiSDR has a nice signal (S7) and picks up the ID on the waterfall

ID at 0127 is "Mix Radio International Worldwide"

reception reports to "[email protected]"

and an eQSL card

Tracking interesting airplanes, some ADS-B based software tools

Assume that you have an ADS-B receiver listening for aircraft. What kind of filters are available for plugging that data feed into something that you control that would emit a stream of "interesting" aircraft? And what tools would you use to build it?

The alerts I've seen have been for aircraft flying in circles ("advisory circular"), specific planes owned by notable people. I'd add anything low flying, blimps, etc.

Bonus points if you can replay recent traffic against new filters.

Some options:

plane-notify

Notify if a selected plane has taken off or landed using OpenSky or ADS-B Exchange data. Compares older data to newer data to determine if a landing or takeoff has occurred. As well as nav modes, emergency squawk and resolution advisory notifications. Can output to Twitter, Discord, Mastodon, and Telegram

This powers the "elonjet" bot.

https://github.com/Jxck-S/plane-notify

qt-adsb-alert

"qt-adsb-alert fetches informations from ADS-B exchange website and sends a mail when interesting planes are near home"

It exposes a bunch of ADS-B variables and lets you write code against them, e.g.

export function sendAlert() { var distOk = (distanceToMe < 50000) || ((distanceToMe < 100000) && (gettingCloser < 20)) return distOk // distance ok }

https://github.com/nefethael/qt-adsb-alert

traffic

"traffic" does air traffic analysis in Python

Its main purpose is to provide data analysis methods commonly applied to trajectories and airspaces. When a specific function is not provided, the access to the underlying structure is direct, through an attribute pointing to a pandas dataframe.

https://github.com/xoolive/traffic

https://traffic-viz.github.io

FCC to eliminate symbol limits on amateur radio transmissions

Dan KB6NU writes

Let the innovation begin! FCC eliminates baud rate limitation

https://www.kb6nu.com/let-the-innovation-begin-fcc-eliminates-baud-rate-limitation/

From the Federal Communications Commission:

Specifically, we remove limitations on the symbol rate (also known as baud rate)—the rate at which the carrier waveform amplitude, frequency, and/or phase is varied to transmit information1—applicable to data emissions in certain amateur bands. The amateur radio community can play a vital role in emergency response communications, but is often unnecessarily hindered by the baud rate limitations in the rules.

https://docs.fcc.gov/public/attachments/FCC-23-93A1.pdf

The ARRL reacts favorably, noting that there is still a bandwidth limit on transmissions in the affected bands.

"Consistent with ARRL’s request, the amended rules will replace the current HF restrictions with a 2.8 kHz bandwidth limit."

http://arrl.org/news/arrl-hails-fcc-action-to-remove-symbol-rate-restrictions

These limitations have been lifted temporarily in the past, when emergency traffic needed more bandwidth (e.g. for Hurricane Ida in 2021), so it's likely that once the restrictions are lifted that modem software like VARA will be able to use these new features right away.

http://www.arrl.org/news/view/fcc-grants-temporary-waiver-to-permit-higher-symbol-rate-data-transmissions-for-hurricane-ida-traffi

Regulations do not go into effect until they are published in the Federal Register (about a 30 day delay).

Getting started with software defined radio

I sent this short note to a local ham who's got a couple of SDR sitting in boxes unused, as a very brief introduction and some pointers to things to try that might be successful on the first go.

---

There's a great blog about the RTL-SDR and other digital radio stuff at

https://www.rtl-sdr.com/

I'd poke around in there first to see what you thought might be interesting.

The very easiest thing to do on any of these is to use them as an FM tuner. Signals are very strong so it hardly matters how bad your antenna is! Depending on what system you are using you might find GQRX for Mac or Linux https://gqrx.dk/ or SDRSharp https://www.rtl-sdr.com/tag/sdrsharp/ for Windows to be useful software to control these.

Another fun exercise is to listen for airplanes, which broadcast on 1090 MHz. One of the easy ways in is to hook up the radio to a Pi and feed the data to Flightaware https://www.flightaware.com/adsb/piaware/ Even if you don't have a Pi handy, decoding ADS-B signals isn't too hard, and with good antenna placement you can decode digital signals from 100+ miles.

Enjoy!

back on the air soon

I'm on an email list that tags along on the side of a daily morning 2 meter net. At various times I've been more active than others on that net, but I stick with it as best I can. There are some regulars who are on every single day, and a broad bunch of folks who show up from time to time as the seasons (and propagation) permits.

A regular on one of these nets has been absent at the usual time. People notice and check in on you. The demographics of ham radio being what it is, this can be of some concern - most folks who have an hour every day to play radio are retired, some for long enough that retirement is a second career.

The message back from the son, relayed a couple of times via net control, reporting on the hospital stay: "Hopefully, we’ll get him back home and back to being on the air soon."

Operating notes 2023-09-17: Hams over IP and Hamshack Hotline on a Cisco SPA525G VOIP phone

Writing this down before I forget it all....

I spent a few hours this weekend setting up a Cisco SPA525G IP phone to get it on the air with the public switched phone network and with two ham radio PBX networks: Hams over IP and Hamshack Hotline.

The first part of the setup really didn't take very long, but it's what had stymied me in the first place: getting the Cisco phone onto our wifi. Turns out you need to match the encryption type of the phone with the encryption type of the router; in my case that meant selecting WPA2 PSK AES. It's all spelled out on page 30 of the Cisco docs - the Cisco 525G user guide - but of course I wasn't looking at the docs as I was fumbling through the various options trying to just make it work.

Once the phone was on the air, the next thing to do was to get it connected to the various VOIP networks I have access to. The helpful thing about this phone is that it has a web server built in, so it's not necessary once you get it online to punch buttons the phone to get all of the details.

I started with Voip.MS which is a subscription based VOIP network that connects you phone to the public switched telephone network. The Voip.MS wiki page for the SPA525G has the necessary information for connecting a line. I had previously set up a line with my cell phone and my MacBook Air using Zoiper, so the configuration involved adding an additional extension to point to the Cisco phone.

The "Phone" tab on the Cisco's web server lets you map lines to extensions. When I had first set things up, all 5 of the extensions pointed to the first line. Map "Line key" to "extension" as appropriate, or keep some lines disabled.

The second system to set up was Hams over IP. This is a "bring your own device" VOIP network for hams. Again there is a wiki page for the Cisco 525g which answers all of the necessary questions for configuration.

Finally I requested and got a link to Ham Shack Hotline or HH. This was a little bit more complicated than the first two. Ham Shack Hotline has a very helpful standard configuration for these devices that fully provisions them according to their specifications, but in the process it wipes out all of the other configs on your phone. If you want to support multiple networks at the same time, you need to get an "experimental" line on their HHUX server. Fortunately, the actual configuration I had been through twice successfully on other providers so even though I was "on my own" to configure things I basically followed the previous setup pattern and all was well.

What can you do with this VOIP configuration?

With the VOIP.ms line I can make regular phone calls. I called and talked to my Mom, the sound quality was fine, the caller ID came through with my name so she knew it was me. I'm looking forward to porting over our home phone line to this system so I can dial out directly with a well-known number.

With Hams over IP and Ham Shack Hotline, I can patch into what is a bewildering variety of linked digital networks. Most of these connections go in some way to linked Allstar nodes, and the corresponding sound quality is quite good.

As an example, I had a QSO with Lucille KD8PTE through Ham Shack Hotline on the K8LOD 147.27+ repeater in Marquette. She was connecting via RF to the repeater, and there's a Ham Shack Hotline interface to the Allstar node, using HH extension 94026. Sound quality was good with none of the "robotic" sorts of sharp edges that you can sometimes hear on DMR connections.

The other connection I made tonight was to Christopher M0YNG who dialed me direct on Hams over IP. The connection was from his PBX in the UK to a softphone running on my MacBook Air (Zoiper) and the sound quality was excellent. (But was it amateur radio? Neither of us were using the ham bands so there was no need to limit our conversation to ham topics.)

All things considered quite some progress! My next step is to take all of this hard-won experience and venture into porting a phone number to my phone, moving the land line number to a new provider. How hard could it be? (And this is definitely not amateur radio.)

Ferrite, an introduction

"Ferrite" is the working name for an amateur radio focus containerized desktop. It is to be based on Universal Blue https://ublue.it/ and is inspired by Ham-Pi, PiSDR, and other related projects that try to corral a whole bunch of ham radio software into a single distribution. The underlying distribution comes from Fedora.

Target hardware includes the RTL-SDR and Airspy HF+ software defined radios. I hope to be able to tune and process and decode ADS-B, APRS, AM, FM (narrowband, wideband, and stereo), SSB, a variety of digital voice modes including DMR, and to decode slow scan TV and radiograms. I'll do the receive side first, and then look at transmitters.

Universal Blue targets a wide range of hardware, so I'll let that project shape my selection of what machine this runs on. The Raspberry Pi would be great to get everything running on, but I'll also hope to get a Chromebook ready setup to better support mobile and portable operations.

(This is from issue 1 in the "Ferrite" repository. I don't have a working version just yet.)