Amateur Radio Weekly – Issue 264
Open-Source passive radar taken down for regulatory reasons
KrakenRF team has stumbled into an arms-trafficing legal roadblock for their KrakenSDR-based passive radar code.
Hack A Day
Turn a 20+ year old Yaesu FT-817 into a CW mean machine
It was quickly becoming clear to me that my humble FT-817 couldn’t cut the mustard in the world of serious CW operating.
Ham Radio Outside the Box
FCC OKs Ham-Military QSOs for Pearl Harbor Day
The FCC has approved an ARRL request to permit contacts to be made between amateur stations and military stations.
CQ Newsroom
Can you handle yet another ‘OTA?
Coming soon to a body of fresh water near you.
AE5X
40 MHz beacon in Denmark off air due to electricity costs
OZ7IGY has an annual electricity bill of more than 2,800 EUR.
EI7GL
FCC Commissioner advocates for preservation of AM Radio
FCC Commissioner Nathan Simington said AM radio is an “indispensable resource.”
Radio World
Turning a trailer wiring harness into ready-made ground radials
Now we have four 25 foot radials. Bonus was all were different colors. Easy to untangle.
QRPer
Raspberry NOAA V2 Edition 2023 image released
Raspberry Pi automated NOAA and Meteor weather satellite capture.
RTL-SDR.com
How to repair a broken solar panel
I learned that solar panels have bypass diodes and that if one fails, it will cause reduced output on a solar panel.
Mikes Tech Blog WB8ERJ
222 MHz: Is anybody there?
Amateur Radio on 222 MHz has endured several reallocations and other changes through the years.
On All Bands
Video
Building your own electric motor
Hannah Fry delves into the inner workings of electric motors.
BBC
Innovative use of screwdriver antenna
Would counterpoises work better if the radials where pointed down at a 45 degree angle?
David Casler
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Amateur Radio Weekly is curated by Cale Mooth K4HCK. Sign up free to receive ham radio's most relevant news, projects, technology and events by e-mail each week at http://www.hamweekly.com.
LHS Episode #491: Beginner Hams Deep Dive
Welcome to the 491st installment of Linux in the Ham Shack. In this deep dive episode, the hosts expand on their topic from the previous episode, focusing on new radio amateurs getting into the hobby. This episode focuses on tips, tricks, insights, recommendations and resources for people new to the hobby. We hope you find this episode entertaining and informative. Have a great week.
73 de The LHS Crew
Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].
CQ WW CW contest wrap up
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].
Amateur Radio Weekly – Issue 263
SKYWARN Recognition Day set for December 3
The annual SKYWARN™ Recognition Day (SRD) on-the-air activity will take place Saturday.
ARRL
Digital Library of Amateur Radio & Communications surpasses 25,000 Items
DLARC has quickly grown to more than 25,000 items, including Ham Radio newsletters, podcasts, videos, books, and catalogs.
DLARC
Survey: How do you find new nets?
We’re researching how the Ham Radio community discovers nets. All information is anonymous.
Amateur Radio Weekly
HF & VHF Ocean Radars – 26 MHz to 43 MHz
Ocean radars measure ocean currents by emitting radio waves from shore-based transmitting antennas.
EI7GL
Decoding the Artemis I Orion vehicle
Seven hours after launch, I used two spare antennas from the Allen Telescope Array to record RF signals from Orion and some of the cubesats.
EA4GPZ / M0HXM
Lithium batteries in the cold: A guide
As a lithium battery cools, the chemical process that creates electricity slows down and the internal resistance of the battery goes up.
Off Grid Ham
The Luxemburg-Gorky effect
A phenomenon of cross modulation between two radio waves.
The SWLing Post
Stand alone SSTV camera
Despite the crude nature of SSTV it works surprisingly well.
Dzls Evil Genius Lair
FUNcube-1 (AO-73) now celebrating nine years in orbit
It has now transmitted more that 16 million data frames.
AMSAT-UK
Video
Exploring a 1 million Watt FM tower
Tour the super tower in Crestwood, MO, serving the entire St. Louis metro area.
Geerling Engineering
DIY sand battery
The theory, practice, and use
Robert Murray-Smith
Iowa Marine Mobile
Had a lot of fun experimenting RMOOTA (Random Metal Objects On The Air) with the boat today.
K0KLB
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Amateur Radio Weekly is curated by Cale Mooth K4HCK. Sign up free to receive ham radio's most relevant news, projects, technology and events by e-mail each week at http://www.hamweekly.com.
CQ WW CW DX contest this weekend!
This weekend the bands will be alive with CW for the CQ WW CW DX contest. If you are not a contester this still is a great weekend to grab some DXCCs for your log book towards an award. If you are a CW contester then hold on and enjoy. Today I spent some time making sure the Hustler 4BTV vertical was ok, updated my contesting software N1MM+, ran a check on the macros and made sure the trusty Icom 7610 and the 9AN5 touch keyer are ready to go. I am hoping Murphy will stay far away this weekend and allow me to enjoy the music of morse!
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].
LHS Episode #490: The Weekender XCIX
It's time once again for The Weekender. This is our departure into the world of hedonism, random topic excursions, whimsy and (hopefully) knowledge. Thanks for listening and, if you happen to get a chance, feel free to call us or e-mail and send us some feedback. Tell us how we're doing. We'd love to hear from you.
73 de The LHS Crew
Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].
Rothamel’s Antenna Book: An Authoritative Source
As an academic researcher, the term “authoritative source” is reserved for works deemed to be the standard by which other scholarship in an area is judged. As a U.S. ham, I’ve purchased the ARRL Antenna Book (both new and used) since I’ve been licensed. Good reading and reference. It’s been a go-to document not only for me but for many State-side hams. There is a new Sheriff in town.
I’ve read about Rothammel’s Antenna Handbook in other publications—Practical Wireless and RadCom, for instance—but it was in German. Alas…Ich spreche kein deutsch! Since 2019, there is an English translation.
On eHam, there is but a single review. James AD0YO says, “This book is amazing! It should be on the desk of any ham interested in antennas. And, that should be all of us. The first 270 pages cover theory. The rest cover all types of antennas.” OK. James loves it. What about others?
A website I often read, the Reeve Observatory near Anchorage AK, has a review: “The information in Rothammel’s Antenna Book appears to be taken from both amateur and professional literature and patents from around the world. Having this book generally will save readers considerable time when looking for details on a particular antenna type or for ideas on what antenna to build for a certain
application. Each chapter has an extensive list of references, so it may be possible to get to the original source document.”
The popular commercial vendor in the U.S., DX Engineering, carries this volume (although out of stock as I write this). It also has only a single review. Two years ago, Juan (no call) wrote, “This is a 1,600 (page) treatise on Antennas! It is more theoretical than the ARRL Antenna Book, but quite less than John Kraus classical textbook. It has a ton of data and practical information. It is a very good comprehensive reference book on antennas.” Another onesy but rave review. No gotchas yet.
Another source I enjoy, Radio User magazine, had this announcement. “The famous Rothammel’s Antenna Book is now, at last, available in English. At the 2019 Hamvention, DARC announced the availability of the wonderful Rothammel’s Antenna Book into English. This translation is of the 13th edition of Rothammels Antennenbuch.” Now I recall my friend, Scott K0MD, telling me that he picked up a copy of this impressive book at Hamvention. Great international reviews. A close friend who bought it and is impressed. Wow! This is getting close to my wallet.
Rothammel. Who is (was) this guy? Wikipedia advises “was” is unfortunately the correct tense as he is now a Silent Key (1914–1987). After reading a short biography on Rothammel, it strikes me that he would be in league with Lawrence Cebik W4RNL, a professor of philosophy at the University of Tennessee in Knoxville, long revered for his antenna work and writing. From the German Wiki, translated to English by Google Translate:
“Rothammel had been a radio amateur since 1932 with his call sign “DE3040/L”. During World War II he served as an Air Force radio operator. Little is currently known about his stay after the war, except that he settled in the Soviet occupation zone – the later GDR.
After the war, he initially worked as a guest and farmer before moving to the postal service of the GDR for ten years. At the post office, he looked after the radio and television transmission systems. After ten years, Rothammel moved to the information and documentation center at the radio equipment factory Stern-Radio in Sonneberg, which later became VEB Stern-Radio Sonneberg . He did this job for 25 years until he retired. Since 1954 Rothammel was active as a radio amateur under the call sign “DM2ABK”, since 1980 under the call sign “Y21BK” or “Y30ABK”.
In addition to his professional activities at the post office and at VEB Stern-Radio, Rothammel was a long-time club station manager in Sonneberg, a member of the examination committee in the Suhl district and an authorized person for the radio performance badge in gold. For five years he wrote articles on VHF topics for the magazine Funkamateur. In addition, he contributed as an author to various publications on the subject of radio, for example the books “Ultra Short Waves”, “Practice of TV Antennas Part 1 and 2” and the “Handbook for Short Wave Amateurs”, etc.”
I ordered a copy of the 1st Edition English translation, copyrighted in 2019, directly from the DARC. Easy order. It took several weeks to arrive via DHL and final delivery by the US Postal Service. I was researching HF loop antennas for an article. I was thrilled at the depth of coverage and the detailed citations and patents included. It greatly helped me organize my thinking on how to improve the design and deployment of an HF horizontal loop antenna. More on that article in the near future as it nears publication in Practical Wireless magazine.
Here’s an illuminating example on a relatively unknown niche type of antenna. Here in the States, due mostly to posts on QRZ.com, the reader would conclude that fractal antennas were wholly invented by Nathan W1YW. As the sportscaster Lee Corso is fond of saying, “not so fast!”. Look at what I read on pp. 948-9:
In the same year (1995), two researchers filed patent applications for something they called, fractal antennas. In May, Dr. Carlos Puente in Spain filed his application which was approved in 1998. Later, in August, Dr. Nathan Cohen filed his patent application in the United States but it was not granted until 2000. As Rothammel states, the priority goes to the first filing. This small point may only matter on legal issues but it’s both enlightening and historically correct for the amateur radio community to know that there were indeed two “inventors” of the fractal antenna line. Lots of good stuff like this in the Rothammel Antenna Book.
So does this book replace the need for the very popular Antenna Handbook by the ARRL? Not at all, as the ARRL book is geared more toward pedagogy and far less on being an authoritative reference. Rothammel’s book, for instance, does not include supplementary software, data files (antenna models, propagation projections, etc.), and such. Editions of the ARRL book do overlap greatly across adjacent editions so that’s caveat emptor for the buying ham. Me? I have quite a number of the ARRL Antenna Handbooks, as well as most things written by Joe Carr and other antenna scholars. Now, the Rothammel’s Antenna Book is on my bookshelf right beside them. I won’t have a problem finding it at 1,600 pages in length!
I can add my own superlative review to those quoted above. It’s not been fully read thus far but the spine and pages are certainly creased quite a bit! I’ve read deeply on loop antennas and through the theory section. It’s now my authoritative resource for amateur radio antennas.
Frank Howell, K4FMH, is a regular contributor to AmateurRadio.com and writes from Mississippi, USA. Contact him at [email protected].