Information about larsthunberg.se

For Amateur Radio information please see this post.

Domänen larsthunberg.se ägs av Lars Thunberg, Sollentuna. Kontakt via e-mail   lars(snabel-a)larsthunberg.se

Om du letar efter ”rätt” Lars Thunberg kan jag nämna att födelseort är Mellösa utanför Flen och födelseår 1972.

För arbetsrelaterade kontakter hänvisar jag till LinkedIn:

This is the homepage of Lars Thunberg in Sollentuna, Sweden. Amateur radio callsign SM0TGU.
e-mail lars(at)larsthunberg.se
For information about satellites and amateur radio please see this page where most of the info are in english.
My linkedin page is http://www.linkedin.com/pub/lars-thunberg/1/442/769

Amateur Radio

XT-60 DIY fused power distribution

Very simple home made (DIY) XT-60 power distribution with fuse, used to distribute low power 12V from the banana plugs of the power supply.

Idea from this video:

Amateur Radio

New UHF SatNOGS antenna direction

2021-12-14: Move direction to south

Amateur Radio

WSPR portable tests with HF loop antenna

Did some WSPR portable tests today during my lunch break with OM0ET MC-20 HF loop antenna. WSPR TRX from ZachTek controlled and powered by GPD MicroPC.

87 unique spotters in 12 minutes on 20 meter. Output is 200 mW.

Amateur Radio

FT8 contact with VK on 28 MHz

My first Australian contact on HF was done via FT8 on 28 MHz 2021-10-27 with VK6EI.

10 watt with IC-705 and EFHW 40-10 antenna.


How to use WiZ lights with Domoticz

WiZ Connected is a series of lights and other Wifi connected IoT. The units are cheap and works well. The WiZ app is actually good and easy to use. But, if you have a Domoticz system you would of course like to integrate the WiZ units. Below are two solutions:

1. Use the Domoticz plugin

Install this plugin:
If you are lucky everything goes OK and you can control your WiZ units.

2. Use UDP commands

I will describe my solution for a Windows system. If you are running Linux I guess it is almost the same.

  1. In your router, add a static IP to your WiZ lights.
  2. Add a virtual (dummy) light in Domoticz.
  3. Download Swiss File Knife and copy just the exe file sfk.exe to a folder, that you will use in step 5 below
  4. In the virtual light you created, have a level for every action you would like, for exemple ”Off” and ”On”.
  5. Connect the level to a script action, see the screenshot below
  6. Now you can control your WiZ lights!

The UDP command lines

I got the idea from this site:

I noticed for sending from a Windows cmd you need to escape the ” sign. As an exemple the command for a light is like this (replace the IP address xx.xx.xx.xx with your fixed IP-address of your light):

Turn ON

sfk udpsend xx.xx.xx.xx:38899 -listen {\"id\":1,\"method\":\"setState\",\"params\":{\"state\":true}}

Turn Off

sfk udpsend xx.xx.xx.xx:38899 -listen {\"id\":1,\"method\":\"setState\",\"params\":{\"state\":false}}

Good luck with your WiZ lights and units!

Amateur Radio

WSPR with Sdrplay RSP1a

Testing RX of WSPR on 20 meter (14 MHz) with Sdrplay RSP1a, SDR Console v3 and WSJT-X.

Amateur Radio

Change broken relay Rot2Prog

The Rot2Prog rotor controller from AlfaSpid has four simple relays that several users has reported to be broken. This has also happened to me – I have a relay that has not function very well for several years. So I decided to try to replaced it.

These releay are very cheap and I found replacement at TME:

l:12VDC;16A/250VAC;16A/24VDC ROHS
Przekaźnik:elektromagnetyczny;SPDT;Ucewki :12VDC;16A/250VAC
Mfr: RELPOL Original part number:



Unmount the board

First remove the top cover by removing the four screws at the side of the chassi. Then remove the two screws holding the board, see image below:

The board is built nice, with ferrite on the input and output cable to prevent RF-noice. If needed to change the board, this can be easy done.

Remove relay

Then desolder the faulty relay. For me, it was one of the azimut direction relay, the one to the left:

It was a pain in the *** to desolder and remove this relay! I was close to give up and nearly destroyed the board. But finally, after two hours, I did managed to remove it. I can not understand why AlfaSpid did not mount a relay socket for easy change…

Solder the new relay

This was an easy task, just solder the 8 legs:

Function test

Now connect all the cables and try it. Hopefully it will now work again!

Good luck!