• 7:00 PM
• ZOOM Virtual Meeting https://zoom.us/join 

1. Sun Clock
2. Grey Line Radio Propagation
3. Ununs, Baluns, and Antenna Tuners

Sun Clock:

1. Sunclock is a Linux application which can be installed on many Linux systems with: "sudo apt-get install sunclock"
2. Step-by-step instructions for installing sunclock on a RaspberryPi Sunclock are found at https://k4pyr.com/wp-content/uploads/2019/06/Raspberry-Pi-World-Sun-Clock-Project.pdf 
3. A web site that displays a "Grey Line Map" refreshed every 5 minutes: https://dx.qsl.net/propagation/greyline.html 

Grey Line Radio Propagation:

1. HF propagation:  https://www.electronics-notes.com/articles/antennas-propagation/ionospheric/hf-propagation-basics.php 
2. Grey line propagation:  https://www.electronics-notes.com/articles/antennas-propagation/ionospheric/greyline-propagation.php 

Ununs, Baluns, and Antenna Tuners:

1. An analysis of several baluns used by hams:  http://karinya.net/g3txq/baluns/baluns.pdf 
2. Another balun discussion:  http://vk5ajl.com/projects/baluns.php 
3.  https://sites.google.com/view/kn9b/guanella-current-balun 
4. Looking at end-fed antennas and ununs:  https://www.kb6nu.com/playing-end-fed-wire-antennas-91-ununs/ 
5. Balun/Unun Construction:  https://www.yccc.org/Articles/Antennas/N1IW/Balun_short_version.ppt 
6. A discussion about antenna tuners:  http://karinya.net/g3txq/tuner_match/ 
7. Toroid sources:
   • http://www.amidoncorp.com/ferrite-toroids/
   • https://www.universal-radio.com/catalog/misc/amidon.html
   • https://palomar-engineers.com/ferrite-products/ferrite-cores/
   • https://www.digikey.com/products/en/magnetics-transformer-inductor-components/ferrite-cores/936
   • https://www.mouser.com/Passive-Components/EMI-Filters-EMI-Suppression/Ferrites/_/N-bw7t4