Tropo DX at LoRa APRS 433 MHz

Late October and early November brought exceptional conditions for long distance DX contacts. The result was not only great result of OL7M guys in MMC contest, but also new and beautiful DX on LoRa APRS. 

The longest two-way contact was achieved from Koruna 1100m asl - isn't that even a LoRa 433MHz world record over land?

F4JPO-10 from JN08wt 1057km

F1ZFC-10 from JN09xi 1039km

And stations which heard me:

RIG there is TTGO LoRa32 with around 30mW and home made 4el. collinear antenna. Installed at the top of the tree in 1100m asl. Solar powered with rest LoRa toys. More there.

The conditions also favoured the lower positions. Here are the weather stations located around the hills in my area. One nice DX came through my apartment window. On the 5th floor with a small 3D printed dipole - OK2ZAW-23.

There is a 3D printed dipole, like on the other weather stations as well. They are all solar panel powered and have RF power around 50mW.

And there were also nice DX for YO gateways... like YO2B-10

Update at solar site in Eagle Mountains: LoRa APRS digi, WX, MeshCom, Meshtastic, LoRa PR

After a long time I finally found the time and made a day trip to the Eagle Mountains to inspect and upgrade the solar site. The trip got a bit complicated when I discovered that I didn't have the keys to QTH OL7M :) Fortunately it was sorted out - thanks Káťo. We loaded up the ladder and headed for the mountains. The morning rain turned into hot and sweltering heat at 1100m. 

I planned to change the batteries and most importantly add new technologies - Meshtastic and MeshCom. I also replaced the SD card in the raspberry PI zero for the LoRa Packet Radio to make both LoRa TRXs operational. Replaced the LoRa APRS WX station etc.

In the end it was a 4h job...

I installed new dipole for 433 and 868 MHz on one boom. 868 MHz is used for LoRa APRS WX station and 433 MHz for MeshCom. There is also new 3el collinear antenna for 868 MHz with 433 MHz filter for Meshtastic.

The power system works by having a main 12V 17Ah battery, this is charged by two solar panels 10 and 20W. My own MPPT charging boards also have battery discharge protection and their own DC-DC converter for 3V3 and 5V. Either board powers 3V3 stuff, like the LoRa APRS Digi and the 5V Raspberry PI zero board. The 3V3 board shuts off the battery when it drops to 11.5V and the 5V board at 12V. The weather station has its own 18650 battery that powers the LoRa APRS WX and the RAK 19003 for the Meshtastic. This metostation monitors and sends the main 12V battery voltage and Meshtastic sends the small battery voltage information. This WX station has its own small solar panel. 

In case the small battery in the WX station becomes disconnected, the main battery will be powered via 3V3 voltage.

There are now:

LoRa APRS digi - OK2ZAW-17

Frequency: 433775 kHz, slow 300bps

ANT: 4el collinear 

Link: APRS.FI

Coverage: there

LoRa APRS WX - OK4ZAW-16

Frequency: 869525 kHz, slow 300bps

ANT: dipole (with 433MHz) 

Link: APRS.FI

LoRa Packet Radio - OK2ZAW-1 and -7

BBS + NODE

Frequency TNC 1: 869525 kHz

preamble = 8 

spreadingFactor = 7

bandwidth = 250000

codingrate = 5 

Frequency TNC 2: 433075 kHz

preamble = 8 

spreadingFactor = 7

bandwidth = 62500

codingrate = 5 

ANT: H-pol Yagi to 210deg.

MeshCom

Project page here

Frequency: 433175 kHz

ANT: dipole (with 868MHz) 

Status: table

Meshtastic

Project page here

Frequency: 869525 kHz

ANT: 3el collinear

Status: graph

Antennas and power boards + raspberry PI zero and LoRa TRX

LoRa APRS WX board with own MPPT power system

LoRa Packet Radio - OK2ZAW-1 and -7

This is an experimental Packet Radio BBS and Node with two LoRa modems. You can find more (including SD card image) here

I tested the possibility of a 100km connection and with a small Yagi antenna there was no problem to communicate without failures. The signal was at 0 - 1dB SNR.

Test at 100km distance from JN79WK

MeshCom

This Austrian project is quite interesting and again uses LoRa modules and the 433.075 MHz frequency. It uses routing technology and so it is not only possible to send messages to users anywhere in the world possibly within a Radio Mesh network.

In the Eagle Mountains I installed a dipole towards approximately 310deg. Even so, I am able to communicate at 100km again only with the dipole at approximately -15dB SNR. When I experimented with the Yagi antenna I achieved up to 5dB SNR.

Are you interested in any of the projects? Feel free to get started :)

Here you can find the necessary HW.

I also plan to offer KIT antennas - dipoles, collinear arrays including splitter and outdoor boxes...

 2m Es 3.6. 2024 (remote from SV2 holiday)

Yesterday, as part of our holiday in Greece, we visited the ruins of the ancient city of Olynthus. This monument reveals the remains of a city more than 3,000 years old. It's unbelievable that even back then they were able to build a 13km long water pipe to feed the fountain :) Today it would not be possible without the supermarket - development of society :) And it is also the development that can't be stopped - in a few moments I could see the remote desktop of my PC on my remote QTH. Something told me to connect and have a look and I couldn't stop wondering - CQ OD5VB. Beautiful signal, QSOs would be possible on SSB, but I'm not equipped for that. So at least FT8. The contact is made in a minute. Ant OD5VB disappears again in the noise. The distance is a nice 2450 km. Interestingly, after a while Pavel OK1ADT from the nearby QTH in Pardubice makes contact, but there is complete silence on the band for me.

After a while 4X/OM2IB and 4X1GA appear. Both only in one period.

First 2m Es in 2024 2.6. (remote from SV2 holiday)

After long months, the long awaited Es on 144MHz arrived. We are spending our holidays in Thessaloniki SV2 at the QTH of Ondra OK1CDJ, where I am active with little HF equipment. In the morning of the 2.6. 2024 I was in QSO with Pavel OK1ADT and we were discussing sadly about bad CONDX, when suddenly I saw CQ UA1ASA KO48 on 2m. Contact was made in a minute. In the meantime I watched 4m and the band opened up nicely to the north.

There is hope for Es on 2m as well. In the afternoon we drive to the centre of Thessaloniki and I forget to charge my mobile phone. I try the remote desktop to my OL7M remote site and the band is full of EA stations! I try to call one and it works. But the phone is dead, so I only manage to call a couple of stations - I'm not using AUTO! I still manage a couple of EAs and IS0. The Es took a surprisingly long time. I still hear some stations even after returning from the city. 

I also managed to find a lot of new stations on 4m. 

144MHz RIG: Adalm Pluto + 2m front-end + 70W PA + 12el G0KSC @ 15m

QTH: OL7M JO80CF

2m QSO 3.6. 2024

2m PSK reporter 2.6. 2024

4m PSK reporter 2.6. 2024

4m QSO 3.6. 2024

 Aurora Borealis May 2024

Something you don't see every day. Or every year... The Aurora Borealis is visible across most of the sky. This was the evening of Friday 10th May 2024.

With the eye you could only see flickering "clouds". My mobile phone didn't see anything, but Lucky's phone caught it in the preview. I alternated between taking pictures and listening to the band. I had the remote on OL7M. The 6m band was full of CW stations, the FT8 signals could not be decoded, they were "spreaded" over a wide area. The view of the 2m band was amazing, lots of stations and on the waterfall you could see beautifully which signals were spread out by the aurora. I gradually tuned in and heard stations from G to EW in beautiful strength. Mila OK1FPR appeared on the band, so I listened for a few moments and even tried 6m. 

The next day I have to help my parents in the cottage and so I quickly pack the IC-9700, CW key, power supply and paper and pencil. I have a small yagi 3m above the ground in the cottage. I set up the radio quite late, tune the band and the first QSO on the IC-9700 is DK3BU.

Then I find G4PIQ, weak signal, but I get 59A on the first try. Then another G, but the conditions disappear for me, the stations get lost and I only hear classic tropo signals. Then the band starts to fizzle and the DX stations are gone. I pack up the TRX and drive home.

Still a nice experience and my first QSO over the aurora. I have to finish the antennas at work, then it will be possible to be QRV faster - not counting the FT8 QSOs...

2m and 6m bands

I have never seen such a high number :)

My small hamshack in cottage, IC-9700, abt 80W and 10el Yagi between cottages