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Welcome! This is my Amateur Radio Propagation Web Site

           Carl Luetzelschwab K9LA

I retired in October 2013 after 41 years as an RF design engineer with Motorola and then with Raytheon (formerly Magnavox). I designed solid-state RF power amplifiers.

If your club would like a presentation via Zoom or Skype on solar topics, propagation, antennas or possibly any other topic, please contact me at

NEW for October 2021 in the Monthly Feature link: Comments Related to Previous Monthly Features.

NEW on October 5, 2021 in the Timely Topics link: plot of the rise of Cycle 25 including September data.

Reminder: Name That Core (a short article that hopefully will allow you to identify your unknown ferrite cores) is in the General link

Reminder: NM7M’s book titled “The Big Gun’s Guide to Low-Band Propagation” is in the 160m link.

Reminder: NM7M’s book titled “The Little Pistol’s Guide to HF Propagation” is in the General link.

Reminder: NM7M’s book titled “Long Path Propagation” is in the General link.

Reminder: NM7M’s book titled “Long Path Propagation - Revisited” is in the General link.

Reminder: NM7M’s book titled “On Ion Chemistry and Propagation” is in the General link.

I have been licensed since October 1961 (my Novice call was WN9AVT). My interest in propagation goes back to my college days at Purdue University (BSEE 1969, MSEE 1972).

This web site contains selected articles and presentations about propagation and solar topics from my writings over the years. These items are grouped into Monthly Feature, Timely Topics, Basic Concepts, Tutorials, General, 160m, HF, VHF and Contesting. Just click on the appropriate link on the left to navigate to these areas.

You can also read about my early Novice days at the My Novice Days link, my aviation days at the Aviation link, RF power amplifiers in the RF Power Amps link, antenna topics in the Antennas link and receive antennas in the Rcv Antennas link.

My wife Vicky AE9YL (first licensed as KB5EAM in 1987 when we lived in the Dallas/Ft worth area) and I have been on several DXpeditions (YK9A, OJ0, and many trips to ZF as ZF2LA and ZF2YL). I am on the Top of the Honor Roll (worked all current DXCC entities), have 160-Meter DXCC and need four zones on 80-Meters for 5BWAZ.

You can contact me at

[home] [Monthly Feature] [Timely Topics] [Basic Concepts] [Tutorials] [General] [160m] [HF] [VHF] [Contesting] [My Novice Days] [Aviation] [RF Power Amps] [Antennas] [Rcv Antennas]