Amateur radio satellites

Updated 2020-07-05

Lars Thunberg – SM0TGU

I have been a radio amateur since 1989, callsign SM0TGU. VHF-communication and satellites has been my first choice and I have been active on the RS-sats, AO-10, AO-13, FO-sats etc. I have been active in AMSAT-SM for many years.

After 15 year of radio silence I started a new setup in 2013 at my new QTH in Sollentuna (north of Stockholm). Now my focus is receiving telemetry from VHF and UHF amateur satellites and cubesats. From the summer 2018 I am also QRV on HF with FT8 on 20 meter band. You can follow me as AMSAT-SM from our Twitter profile.

Jag har varit licensierad radioamatör sedan slutet av 1980-talet med signalen SM0TGU. 1993 gjorde jag lumpen på S1 Enköping som en av de sista telegrafisterna inom armén och fick därmed även licens för kortvågsbanden. Jag körde i början av 1990 mycket satellit bla. från de ryska RS-satelliterna, AO-10 och AO-13. De roligaste stunderna hade jag via DX-satelliten AO-13 där jag med enkel utrustning körde stora delar av världen. Jag har även byggt egna digitala modem (tex. packet och RTTY) och antenner av olika slag.

Sedan min flytt till Stockholm i slutet av 90-talet hade jag en längre period där jag var QRT men under 2013 har jag åter igen börjat lyssna på satelliter och mitt främsta intresse är nu telemetrimottagning. Jag har alltid varit med runt styrelsen i AMSAT-SM och följer kontinuerligt utvecklingen inom vår hobby. Jag kan med nuvarande utrustning lyssna på samtliga forsknings- och amatörradiosatelliter som sänder på radioamatörbanden på VHF och UHF.
Från sommaren 2018 är jag även QRV på HF (endast 20 meter) och då främst digitala mode FT8.

Jag är aktiv inom föreningen AMSAT-SM som är en intresseförening inom amatörradiosatelliter. Alla mina blogginlägg skriver jag på föreningens hemsida.


Current radio setup

VHF/UHF yagi setup
New UHF LFA X-yagi will be installed spring 2020!

This is my primary setup for receiving satellites (note that UHF yagis is sold):

  • 4 meter 50mm steel pole/mast.
  • Rotor RAS from SPID Elektronik – computer controlled via USB.
  • Vårgårda satellite kit 2 * 6 el on VHF mounted in 45 degrees angle with circular polarization according to the WRAPS construction.
  • New UHF LFA X-yagi will be installed spring 2020!
  • LNA from SHF-Elektronik: Mini-2 and Mini-70.
  • SMA relay EME144 from Minikits for VHF placed after the LNA.
    See this post – measurement of the relay.
    UHF will be replaced with high quality N-connector relays.
  • 2 X 16m RFC 400 low loss coax with N connectors (one for VHF, one for UHF). I have measured the loss after the LNA at the antenna to the SDR unit in office and it is very small, approx 1 dB.
  • Inside at my office I use a MFJ-916BN diplexer in front of the Airspy to be able to use VHF and UHF yagi systems without any need for coax relay. If needed it is possible to disconnect one of the yagis from the diplexer and connect it to a transmitter.

AlfaSpid RAS Az/El rotor
AlfaSpid RAS Az/El rotor during inhouse testing

 

Waterproof Box for coaxreley and LNA
Waterproof Box for coax relay and LNA

SatNOGS station

Start of SatNOGS station was in july 2019 and is base on Rasberry PI3 and a RTL-SDR v3. My station ID is: 858 – SM0TGU – VHF
More information about SatNOGS can be found here.

For VHF 145 MHz I’m using a Vinnant Turnstile Antenna (Crossed Dipole) from eBay seller stanislavpalo130. It is a very good omni antenna for satellite RX and is Right Hand Circular Polarized (RHCP) and gives a much less fading of the signal. It is also OK for various scanning in a wider freq spectrum.

For UHF 436 MHz I have a DIY V-dipole with reflextors. I will replace this antenna in the future with something better…

The current setup for SatNOGS station is:

  • Vinnant Turnstile Antenna (Crossed Dipole) RCHP 145MHz antenna
  • UHF 436 MHz V-dipole with reflectors (DIY)
  • MFJ-916BN VHF/UHF diplexer connecting the two antennas to the LNA
  • MINI-BB LNA 50 – 2500 MHz (from sept 2019)
  • 21 m RFC 400 low loss coax with N connectors

VHF Crossed dipole and UHF V-dipole
Diplexer and LNA

MINI BB broadband LNA


Installation of RPI and RTL-SDR v3 at radio chack


NOAA 137 MHz weather images

For receiving NOAA weather images I am using software WXtoImg and my 145 MHz VHF antennas.


HF antenna and other

With the antenna below I can receive signal from all continents with FT8 and my signal has been heard on all continents with 2,5 watts.

  • LDG RT-100 remote tuner
  • MFJ-813 QRP SWR meter
  • Antenna homemade EFHW 4010, tunable from 80m to 10m. It is resonant on 40m.
    See this post about the antenna and trafo.
  • Approx 20 m Hyperflex 5 coax cable
  • Only digital modes with WSJT-X software.
RT-100 tuner and EFHW trafo
RT-100 tuner and EFHW trafo

SDR-radio and decoding software
I’m mainly using SDR radios because I do not transmit and it is very easy to connect to decoding software:

  • Airspy Mini
  • RTL-SDR v3  SDR Dongle
  • Main SW: SDR-Radio v3 with satellite tracking, frq doppler control and rotor control.
  • SDR#
  • PstRotator for controlling the RAS rotor and linking with SDR Console.
  • Several software for telemetry decoding, sound piping, tracking etc. (Soundmodem, DK3WN telemetry software etc).

HF/VHF/UHF Transceivers

  • HF: RS-918SSB HF SDR TRX
  • VHF/UHF: Baofeng UV-5R handheld
  • Planned HF/VIHF/UHF: Icom IC-705

Planned portable equipment
I’m planning to upgrade my current RX satellite setup to include a portable equipment for making satellite QSOs while going on road trip. Please feel free to comment – anything that should be changed or added? One very good link/article about a portable setup is this one from Ivo Klinkert, PA1IVO.

Transceiver
The new not yet released ICOM IC-705 or my RS-918 HF SDR.
Same useful add-ons for the IC-705 that I would like to have:

  • A headset (see this post)
  • Or maybe a Bluetooth headset for the IC-705

Batteries

  • Turnigy LiPo 5000 mAh. Please see this post about my batteries.

Antenna VHF/UHF

Antenna HF, cables and connectors

  • DIY 1:64 Trafo, tuned EFHW with pico-traps from SOTABeams. This antenna is not yet built…
  • Fixed 15m (21 MHz) dipole
  • Fixed 20m (14 MHz) dipole
  • BNC connectors as standard
  • HyperFlex 5 coax cable (short, aprox 7 meter)

And a simple FM sat setup

  • My current Baofeng UV-5R
  • DIY Moxon-style hand-held yagi

2 Comments

  1. Göran SM5HIH
    2015/12/21 @ 00:03

    Tack snälla Lasse för Din information på Din hemsida. Har läst och måste jag erkänna blivit avundsjuk!

    Reply

  2. Lars Thunberg
    2015/12/21 @ 11:34

    Tack Göran!

    Reply

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