NARSA Approaching!

It’s April and that means that it will shortly be the NARSA day rally. Last year the organisers took a slightly different approach to focus more on clubs and what clubs are doing. As a club we had a narrow band QO100 station on both transmit and receive and a 5GHz TV demonstration, and this year to expand on that we are planning on both the QO100 narrow band transmit and receive as well as QO100 TV receive.

Alongside the QO100 station we are also demonstrating some club projects based on LoRa modules, (MeshCom, Meshtastic and TinyGS). We’ve decided to focus on TinyGS as with the telemetry received and decided that has the most interesting display for the rally.

It’ll be interesting to see what other clubs are up to and hopefully give us some inspiration for future projects and talks.

IF Board

I’ve added the remaining components to the IF board, so I’ll need to get on with testing it at some point, I’m bound to have missed something or got something connected incorrectly. As I added the remaining components I realised that I’d managed to miss the 3p3 capacitor from my last order so that delayed completion, however I also had a bunch of components for the two-tone tester to order anyway.

IF Board Progress

My sudden SSB TRx is long overdue some work and I’ve finally make a little progress, I’m missing a few components but got the remainder of the toroids wound and installed and added the capacitors for the crystal filter. Once the other components have arrived I’ll finish this off, I’ve also ordered the components for the s-meter driver and two-tone tester so I can make a start on them.

MeshCom

After the talk on using LoRa ESP32 for TinyGS Mike G4VSS was on the lookout for more LoRa projects to work on and at the Friedrichshafen Ham Radio Conference came across MeshCom. He became the first UK based station on the project followed by the G0WRS unit at the WARC clubhouse, G7MNP and G8KBB.

I decided to give it a go and it’s been a fairly simple but interesting project.

I used another LILYGO TTGO LoRa32 board and of course first of all I had to flash it, I used the ESP-Flasher (via a Windows VM) available from https://icssw.org/en/meshcom under the Instruction section and loaded the available firmware for my hardware.

Since originally flashing my board I have been pointed toward a simpler option, using the online “flasher” at https://oe1kfr.com/esptool, you just need Google Chrome or Microsoft Edge. The online tool does everything for you, you select your harware version and follow the prompts, no need to download the firmware, the online flasher also has the pre-releases available too.

Once flashed you can connect to the board directly via serial port using the terminal on Mac/Linux or PuTTY or similar on Windows, however the simpler option is to download the app for iPhone or Android from the above link (iPhone app is currently in Beta so you download the testflight app and click the testflight link given on the website).

The app is very simple, first of all you “Scan BLE Devices” and connect to your gatway, then there are just a few settings to be filled in:

Callsign: Fill in your callsign plus an APRS SSID, this seems to be 12 for gateways (connected to the internet) and 1, 2, 3… for non gateway, so for my gateway G5JIM-12.

Set Location – Phone GPS: If your device doesn’t have GPS you can set the position with your phone, and you can se the regularity with which your phone updates the location at an interval of between 3-60 mins under “Phone sends Position”.

WiFi Settings: Required for GATEWAY use.

APRS Settings: Not required but fill in if you want to.

GATEWAY: Self explanitory, select the GATEWAY option for a gateway (and fill in the WiFi settings).

Tx-Pwr: You can choose your transmit power level.

Once thats done just select “Save Settings to Node” and it will take you to the chat and you can start communicating via the text messages, checking the node map and seeing if you have spotted any other units.

There was a slight issue in that the firmware version I was using 4.24 where negative co-ordinates weren’t properly recognised so the position was incorrect on the map, I attempted to install the 4.26 version which has a fix to resolve this, however there was to be a memory issue for my version of the hardware which meant it didn’t work. The developer of the firmware Rainer OE1KFR and the whole community have been really helpful and within a couple of days a new firmware version was out – and that was despite Rainer having to prepare for an exam! I can’t emphasise enough how great the support has been.

Antenna Overhaul

Having tried virtually everything to make the existing setup work I’ve done some digging into the possible issues and decided to change the wire I’m using. Up until now I’ve been using what I thought was solid copper speaker wire, but as it turns out it’s in fact copper coated, so I’ve decided to change to 2.5mm2 singles.

As well as changing the wire I’m also using adhesive lined heat shrink crimp connectors and liquid electric tape to waterproof the connectors as much as possible. The first image was me testing the connector on some of my old cable, you can see the glue of the adhesive lining in the image. The second image is the final product with the liquid electric tape.

Previously the 40m legs ran down from the balun to the corners of the roof and then around the gutter clipped on, with the 20m legs they ran to the centre point between the pole/balun and the corner of the roof then along the gutter (to keep the 20m and 40m legs separated).

This time as I replaced the legs of the dipole I decided to run the 40m legs over the roof, partly as it was easier than clipping all the way around, but also to keep it raised a little more, this also meant that I could run the 20m legs directly to the corners of the house.

One issue I found with running the 40m legs over the roof rather than round the gutter was that it was very close to the roof tiles, thus causing SWR changes in the wet, to combat this I used a ring camera solar panel mount to raise it a little above the gutter level, not ideal but doing the job for the time being.

I have been really happy with the outcome of the work and have had some great DX on FT8 as well as some less impressive DX on CW and SSB. On FT8 I managed my first Australia, Indonesia, Saudi Arabia and Uruguay contacts amongst others, and on SSB my first USA contact.

I know that propagation has a lot more to do with these contacts than the antenna, but nonetheless I am very happy with the performance so far, I am just hoping that it lasts longer than previous attempts!

TinyGS

Recently Mike G4VSS did a talk at Warrington Amateur Radio Club about using an ESP32 LoRa module with the TinyGS (Tiny Ground Station) project for receiving data from satellites. As a quick introduction the TinyGS website states “TinyGS is an open network of Ground Stations distributed around the world to receive and operate LoRa satellites, weather probes and other flying objects, using cheap and versatile modules.”

One of the big advantages of this project is that it is low cost and available for anyone to attempt, no Amateur Radio license required.

The website displays all stations and you can zoom in for more granularity.

The satellite data that you receive is available on the TinyGS website, both in aggregate form so you can see the locations and heat map of where you have received from (this can be customised to show different power levels, turn off the heat map etc) as well as how many packets have been received per day…

…and data received from individual satellites, both in raw and xml form as well as decoded where possible. This means that you can see the details of the state of the satellite, battery voltage, temperature, solar panel voltage and current.

Along with this you can see which other stations also received from that satellite.

As previously mentioned this is a low cost project, at it’s minimum all you need is the £25 LoRa board with the included mini antenna, placed by the window you would still receive some data. As an upgrade from that Mike’s station is a self contained waterproof unit created using plumbing fittings with a small 1/4 wave vertical and battery, again very cheap just requiring a bit of work to put together.

I decided to purchase one of the boards and set up a receiving station, as I have a 70cm/2m colinear antenna on my roof I decided to use that to make a start. The process of setting up the board was fairly simple, with just a couple of hiccups:

1. Ensure that the cable you use is a data cable not just a charging cable, not all mini USB cables are created equal!

2. There are a number of ways to flash the LoRa module. I originally wanted to do it directly on my Mac so I attempted using TinyGS_Uploader for Mac, but this didn’t work, so instead via a Windows VM I used TinyGS_Uploader for Windows. The recommended way seems to be to use PlatformIO, but it isn’t available for the IDE I usually use, rather than downloading an IDE simply to install the PlatformIO plugin I decided to just use the TinyGS_Uploader which worked fine. To find the TinyGS_Uploader (and there is one for Linux too) you can just go to the Wiki link on tinygs.org and scroll down to “Quick Start”.

3. The link to the telegram group where you can get the credentials for MQTT_USER and MQTT_PASS seemed to be wrong, thats just the tinyGS Community chat (which is also linked from the home page on tinygs.org), @tinygs_personal_bot is the one to use.

Some of these images were taken after the original post was written, hence the dates!

Antenna Inspection

Once again, almost like clockwork, my antenna started exhibiting issues a year on from being overhauled. Despite my efforts using epoxy resin in the crimp connectors to make them watertight, the legs of the fan dipole have started to deteriorate at the crimp, however inspecting it wasn’t as simple as I’d hoped.

My first issue on inspecting this was that the pulley rope had almost completely disintegrated, once I discovered this I didn’t want to leave it as it was and felt that I needed to replace it immediately, but it turned out that was a bit of a nightmare to replace.

My first effort was to use a brick line to attach the new rope to the old rope, that was a mistake! The brick line being so thin slid down the side of the pulley and took a lot of work with electricians rods and a loft opening pole to get it back on, once back on I was able to run the new rope across. Another issue I came across was that the pulley has seized in place, not a huge issue but not ideal and wont do the rope any favours, however I’ll deal with that another day!

In a typical manner I ended up spending the day sorting an issue which I wasn’t even aware existed until I started looking at something else, other than seeing that the wire in the crimps had deteriorated I didn’t get the chance to fix anything, that is to follow.

NARSA Rally 2023

On the 23rd of April it was the 2023 NARSA rally.

This year marked a change in how the rally was being approached. Increasingly and particularly thanks to Covid (or at least so I understand) the larger traders have been staying away from rallies, not seeing it worth their while, so NARSA decided to focus less on big traders and more on clubs and what clubs have been doing.

As a club we decided to try to build on what we’d exhibited last year. In 2022 alongside the usual selection of club projects on display we had a satellite ground station receiving video from QO-100. This year rather than just receiving we decided to put on a fully operating narrow band ground station which we operated throughout the day, in addition we had a camera on the station, the video from which we transmitted across the room via a 5GHz link and then streamed to the BATC streamer via a Portsdown device. Putting all this together was a big job, and I learned a lot through assisting.

It was a very enjoyable day and I thought the mix of club stands and smaller traders was great, in particular there was a fantastic selection of components, I’ll definitely put some more thought into what I need for the shack before I go next time.

Hopefully the club focused aspect will continue to grow and it’ll continue to stand as a real radio amateurs rally furthering the hobby!