Lecture and Lab, August 2022

The QFH Antenna, courtesy of Eugene Ruperto, W3KH

The latest revision of the instruction sheet and information guide is now available. I’ve also added some information about on-line resources.

The August, 2022, Lecture and Lab will be held in-person at the Dallas Medical Center on Saturday, August 27th, at 10:00 am. We’ll have an antenna build and a presentation, too. The antenna we build will be a 137-MHz helicoidal loop antenna pair for receiving weather satellite images and aircraft radio voice transmissions. The presentation will discuss the best software tools for decoding satellite imagery for yourself. The antenna will be very easy to build, and the cost will be only $30.00. 20 kits will be available!

You’ll need to bring a soldering iron and some general hand tools such as a tape measure, a sharpie, and your favorite set of files. The club will provide the antenna parts, but not the receiver: you’ll want to have a device that can receive signals at about 137 MHz. Most ham radios can’t do that, so now’s the time to check on your scanner or even order an RTL-SDR dongle or one of its competitors like an Airspy or SDR-Play. You’ll also want an adapter from a PL-259 connector to whatever connector your receiver uses.

I hope to see you there!

On-Line Resources:

I have used both Gpredict (http://gpredict.oz9aec.net/) and Orbitron (http://www.stoff.pl/) for satellite tracking. Orbitron is rather old, but is useful because it can send commands to other programs when a satellite rises above the horizon.

For QFH Antennas in General:

I downloaded the hole-drilling guides for 2-inch pipe from https://github.com/kmkingsbury/pvc-qfh-antenna. (The author’s main article is here: https://www.instructables.com/NOAA-Satellite-Signals-with-a-PVC-QFH-Antenna-and-/) However, I had a great deal of trouble using the on-line calculators he refers to, provided by John Coppens.

I strongly recommend the QFH papers by Eugene Ruperto, W3KH (SK) and John Portune, W6NBC, published in QST and in various editions of the ARRL Antenna Book.

If you’ve never used an amateur radio satellite and you don’t, for example, know what “keps” are, you should read a general guide to getting started with amateur radio satellites, such as the one from the ARRL: https://www.amsat.org/wordpress/xtra/Getting%20Started%201.pdf

For NOAA Reception:

WXToImg is a convenient tool for recording and processing NOAA weather satellite pictures; I’ve just begun to understand all its capabilities. Unfortunately, the program has been completely abandoned by its author and requires some effort to use. https://wxtoimgrestored.xyz/

When using WXToImg, it is vital that you go to Options → Active APT Satellites and disable NOAA 17. Failure to do this will cause the program to hang. NOAA 17 broke apart into pieces, and no orbital elements are published for it. You should also update the satellite frequencies as shown.

There are many guides on-line to receiving images from NOAA weather satellites. For example, this tutorial at RTL-SDR.com is helpful: https://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weather-satellite-images/

In general, I use an RTL-SDR Dongle tuned by SDR Sharp: https://airspy.com/download/

Connected to the input of the free and very useful VB-Cable: https://vb-audio.com/Cable/

And WxoImg is connected to the output of VB-Cable.

AMSAT.org also has been spreading the word about a NOAA satellite reception guide by Sam, N7FNV and Dale, KJ6IX. Be aware that under Windows 10 and 11, the Orbitron configuration file may not be where you expect it to be! You’ll want to edit the setup.cfg file located in:

C:\Users\[YOUR USER NAME]\AppData\Local\VirtualStore\Program Files (x86)\Orbitron\Config

The guide also omits instructions for putting WXtoImg into “Auto Record” mode, which you’ll need to do in order to receive anything.

For METEOR-M2 Reception

A simple, pre-configured software suite for receiving Russian Meteor-M2 images can be downloaded
from Les Hamilton: https://leshamilton.co.uk/MeteorGIS.htm. I strongly recommend using this for
your first satellite passes.

A very detailed and more up-to-date guide is available from Happysat:

Hapysat also provides up-to-date satellite status information for the Meteors: