LoRa APRS digi and LoRa Packet Radio experiments

LoRa boards are becoming very popular in the HAM community. Advantage is in price and also incredible sensitivity. With very small power (20-80 mW) you are able to make DX over hundrets of km. 

I have updated my LoRa point in Eagle Mountains to ver. 4.0 :) a few weeks ago. It is solar powered hardware with 4el for DiGi OK2ZAW-17, WX station OK2ZAW-15 (broken wind sensors) and new LoRa Packet Radio experimental 2m APRS RX, node and BBS (OK2ZAW-1 and -7). 

Very nice Tropo ducting came a few days after update. New ODX DF0AP-15 and 707 km!

Inside of the box: LoRa WX station, 2x solar power system (own design), Raspberry pi zero with LoRa module and RTL-SDR for 144,8 MHz APRS RX.

New Packet Radio has LoRa module as a link radio. Raspberry Pi zero works as BBS, node and 2m APRS receiver. All decoded packets from 2m are sent by the LoRa link down to another Raspberry and then to APRS network. Power consumption of the raspberry is 1W + RTL-SDR (running) 1W. Weather station measure temperature, presure, wind (demaged sensor) and voltage of the ACU:

Decoded LoRa packet Radio with APRS packets down at OL7M QTH.

 3D printed Collinear ant for 2m & 70cm (APRS & LoRa)

I am playing with the LoRa APRS for some time. It is quite a funny what a DX you can have with a few mW of RF power. I had some X30 and X50 antennas and I was thinking about something more powerful. Collinear antennas are a good choice and when my friend did drawing of dipole holders for me, I could just simply printed it. Building of antenna was a question of one Sunday. There is simly drawing. 

There are STL files for 2m and 70cm version. It is designed for 30mm main pipe and dipoles are made from 10mm (2m) and 8mm (70cm) Al Pipe.

There are dimensions of the dipoles. Final SWR was under 1:1,1 at 145 MHz and 1:1,2 at 434 MHz:

And examle of instalation at OK2ZAW-17 solar powered DiGi in the Eagle Mountains 1100m asl.

More APRS and LoRa APRS posts here.

 40m 4el Yagi - part 5: ERECTING

This is the biggest project at OL7M after the H-frame 4 x 6 el G0KSC system for 10m (link). Started about 10 years ago. Jiri OK1RI designed it in 2012.

This 4 el 40m Yagi project is over thousand hours of work. BIG thanks to Jiri OK1RI for many hours of designing. The result is incredible: designed results are the same as reality! Despite the facts that there were a lot of unknowns. We also have to thanks to Father of Jarda OK1XUB for mechanical designs and all consultations, Pida for climbing and many many other who were participated in this big and long project.

There are some parameters:

Boom length:                    19,05 m / 62,5 ft

Boom weight:                    130 kg - special dural triangle 70x70x70 cm

Longest element:             23 m / 75,46 ft

Elements weight :            190 kg - dural - 14 tubings, biggest diameter 100/5 mm

Tower height:                    36 m / 118 ft - triangle 80x80x80 cm

SWR:                                  less than 1:1,2 (7,000 to 7,200 MHz)

With 5m of coax

All posts about this project are there (link).