Archive for the ‘antenna’ Category

AI Analysis of Logs for Antenna Directionality

Where is this dang thing pointing?

Wire antennas generally have directionality broadside to the antenna but multi-band antennas have "lobes" of directionality that vary greatly as you go up in frequency from their fundamental frequency.  I can generate a KML file of my contacts from the Log4OM logging software, but it is a bit overwhelming and I don't have the ability to break it down by band.



I wondered what Google Gemini AI would determine from evaluating the contacts from my LOTW logs and how that differed from the theoretical directionality of the antenna.  I have over 2800 logged QSOs in LOTW that I provided for evaluation.

I have made a lot of contacts when portable but I paper log those and they rarely make it back into my electronic logs, so nearly all of these logs are from my station operation and 95% of those have been on the 80m OCF.

Gemini provided me with this evaluation


  • 80m: Broad "figure-8" pattern with maximum radiation broadside to the wire at 55° (NE) and 235° (SW).
  • 40m: A "four-leaf clover" pattern. Your strongest performance is at 45° and 315°, perfectly hitting Europe and the US Midwest.
  • 20m: Four sharp lobes that pull closer to the wire axis. Your log shows high-gain "spikes" at 35° (Europe) and 330° (West Coast).
  • 10m: Eight or more very narrow lobes. Your 10m contacts are extremely directional, primarily clustering at 50° and 130°.

I then asked Gemini to evaluate how my log results differ from the theoretical directionality of the antenna.  In general the results match the theoretical performance of the antenna.  I also asked it to include the results from 30m and 17m in this analysis:

  • 80m, Broad Figure-8, Strongly Biased NE/SW: Contacts cluster at 55° and 235°. Coverage is broad but noticeably stronger toward the Northeast US/Canada. High: Matches the broadside radiation of a dipole.
  • 40m, 4-Leaf Clover, 4 Strong Peaks: Contacts are highly concentrated at 45°, 135°, 225°, and 315°. You are successfully hitting Europe and the US West Coast via these distinct lobes. Very High: Confirms the 2nd harmonic pattern.
  • 30m, Distorted 6-Lobe, NW Dominant: You have a massive cluster toward the Northwest (330°). This band is notoriously asymmetrical on an OCF antenna, and your log shows you've "found" the dominant lobe. Moderate: The theoretical pattern is messy; your data simplifies it.
  • 20m, 4 Long, Sharp Lobes, Sharp Spikes: Contacts are extremely localized at 35° (Northern Europe) and 330° (Washington/Oregon). This matches the narrowing of lobes as frequency increases. High: Matches the "tilting" of lobes toward the wire axis.
  • 17m, 6 Very Sharp Lobes , Strategic Clusters: Contacts cluster at 13° (New York/New England) and 225° (Mexico). The narrowness of these clusters indicates you are operating within high-gain "fingers" of radiation.  High: Confirms the 5th harmonic pattern.
  • 10m, 8+ Needle-Thin Lobes, Pinpoint DX: You have specific, isolated successes at 50° and 130°. Many other directions show "nulls" where no contacts were made. Moderate: High-QSB (fading) makes this band less predictable.

Conclusions

Using AI to provide me with analysis of my antenna directionality was certainly faster than manually breaking down all the data and plotting it myself.  I can also see how much I'm likely missing on 20m and 10m due to the severe directionality of the few lobes.  I would be well served by having separate antennas for those bands, but I am very limited where I can put outdoor antennas given the lack of tall support structures at my house. The OCF works because the tallest thing in my lot is the peak of my roof and I have too short a distance to the tree in front of my house for a fan dipole to work.

I did look at some tools for evaluating directionality based on logs such as https://qsomap.org but the ones I found are visual and require manually evaluating the graphics.  There are likely other tools that would do what the AI is doing but I'm not aware of them yet.  Please leave a comment if there are log analysis tools that you use for this purpose.

The analysis of the 30m being severely clumped showed me that I could likely do better using my attic antenna for that band, but I had pretty much given up using the attic antenna years ago due to high receive noise given it's proximity to all the noise in the house.  Now that I have a Loop on Ground receive antenna that allows for quiet receive I will begin using the attic antenna for transmitting and try to determine how its directionality differs for the for the WARC bands that the 80m OCF is extremely inefficient on.

That's all for now,

Lower your power and raise your expectations, or let AI tell you what you should expect.

DE AA4OO - Rich

Long Duration M-Class Flare, and More (Livestream)

This livestream recording is from September 1, 2024 – the NW7US Radio Communications Channel Livestream.  We do this livestream every Sunday at 21:15 UTC.  Here is the link to the livestream from this past Sunday:

The livestream list is here:

https://www.youtube.com/@nw7us/streams

I hope to see you in our livestream live chat, during the next session on Sunday, at 21:15 UTC.  See you there!

 

Livestream: Space WX, Propagation, Amateur Radio – Sundays

Join us, every Sunday at 21:15 UTC (5:15 PM, Eastern Daylight Time, 4:15 PM Standard), for an informal livestream chat session about:
– current space weather — the Sun/Earth connection — including sunspot activity, solar x-ray flares, and geomagnetic activity, as well as,
– current radio signal propagation conditions on the shortwave (high-frequency, or HF) radio spectrum. We also discuss,
– amateur (ham) radio, shortwave radio, and other related topics such as HF antennas (dipoles, doublets, Yagi antennas, and so on).
You can ask questions, and we will discuss some of them now, and some of them in upcoming videos.
Join us every Sunday for Livestream at 21:15 UTC

Join us every Sunday for Livestream at 21:15 UTC

Don’t forget to click ‘Subscribe’, ‘Join’, then, set the Alert Bell to “All” – so you don’t miss any session! You can ask your questions early, on this post.
Every livestream is posted here, so bookmark this link:  https://www.youtube.com/@nw7us/streams
See you there!

Exploring Shortwave Radio Signals: A Peek into Non-Local Communications

Curious about what you can hear on shortwave ham radio? This video is a brief survey of the diverse world of communications on the shortwave spectrum. Expand your radio horizons and enhance your emergency communication preparedness by tuning in to the world of shortwave ham radio.

If you’ve started delving into radio communications beyond local stations and channels, like VHF and UHF, you’re in for a treat. Shortwave radio opens up a whole new realm of signals to explore, including emergency communications vital during natural disasters.

[embedyt] https://www.youtube.com/watch?v=pIVesUzNP2U[/embedyt]

Shortwave radio covers a range of radio frequencies from 3 kHz to 30 MHz. This spectrum is home to a diverse array of radio signals that cater to various communication needs, making it a hub of activity and connectivity.

Within these high frequencies, you can tune in to a multitude of transmissions, from transoceanic air traffic control communications to the chatter of ships navigating the vast seas. Imagine hearing the voices of fishermen, much like those on your favorite reality TV shows about high-seas fishing adventures, along with military communications and the vibrant world of amateur radio enthusiasts.

One of the remarkable features of high-frequency (HF) radio is its ability to propagate signals over long distances, transcending line-of-sight limitations. This means that HF radio enables communication between different regions and even continents, fostering connectivity across vast distances.

During times of crisis and natural disasters, shortwave frequencies become invaluable for emergency communications. When local infrastructure falters or is disrupted, shortwave radio serves as a vital lifeline, facilitating critical two-way communications in and out of disaster-stricken areas.

Explore the fascinating realm of shortwave radio, where distant voices blend with essential information, bridging gaps and connecting communities in times of need. Uncover the power of HF radio to transcend boundaries and provide lifelines when they are needed most.

In this video, I give you a glimpse of the voice and data transmissions I pick up on my high-frequency amateur radio transceiver (in this video, an Icom IC-7000). In later videos, I will dive deeper into specific types of HF communications, such as aeronautical trans-oceanic signals.

German Teletype (RTTY) Weather on HF (Shortwave) Radio

This is a video of the German Weather Broadcast from DWD, Hamburg, on shortwave (HF), using teletype (RTTY). I demonstrate two decoding software options: JWcomm32 (older), and, FLdigi. Note the in FLdigi, the “Reverse” feather is selected to properly decode the signal (in either USB or LSB, you still need to select, “Reverse”).

The radio used to receive these weather bulletins is an Icom IC-7610, using an antenna designed for 160 Meters.

RTTY is a system for broadcasting text over radio. The technology dates back to the late 1950s and seems somewhat anachronistic. Speeds are slow, even slower than NAVTEX. A similar service is the USCG service, SITOR (Simplex Teletype Over Radio) providing offshore and coastal forecasts over very wide and remote areas from the tropics to the polar regions.

There is dedicated equipment to receive RTTY and SITOR but we can receive both using a standard HF/SSB receiver with software packages such as TRUETTY and SEATTY to decode the signals.

The main advantage of RTTY/SITOR is the reception of information over an entire ocean area. The USCG also shares frequencies across multiple transmitters according to a schedule, rather like NAVTEX. The system is available over the Atlantic and Pacific including polar regions not served. For more about SITOR see the Monitoring Times link or the USCG site.

Around Western Europe and the Mediterranean, the Deutscher Wetterdienst (DWD) , the German Weather Service has accepted the responsibility to broadcast weather information for mariners on RTTY. Frequencies are in the table on the webpage at:
https://weather.mailasail.com/Franks-Weather/Radio-Teletype-Weather-Broadcasts

This video captures the RTTY transmission on 14467.3 kHz (with adjustment in the passband to center on Mark and Space as seen in the video).

DWD (Hamburg) Broadcast Content:

Some broadcasts are of raw weather observations in a WMO coded form. Otherwise, for the broadcasts include,

  • Strong wind, gale and storm warnings for German Bight, Western and Southern Baltic Sea, German North Sea and Baltic Sea coast
  • Weather forecast for the North Sea and Baltic Sea, Weather situation, forecast valid for 12 hours and outlook valid for another 12 hours
  • Weather report German North Sea and Baltic Sea coast, Weather situation and forecast valid for 12 hours.
  • Navigational warnings for North Sea, Baltic Sea and German coast
  • Weather report Norwegian Sea and Baltic Sea Route North Cape – Shetlands, The Quark – Gulf of Finland. Weather situation and time series forecast for 2 days
  • Weather report North Atlantic. Route Pentlands – Southwest Greenland. Weather situation and time series forecast for 2 days
  • Station reports North Sea and Baltic Sea
  • Weather report Western European Sea. Route Southern Ireland – Area Canarias. Weather situation and time series forecast for 2 days
  • Medium range weather report North Sea, Weather situation and time series forecast for 5 days
  • For the Mediterranean there are Station reports Mediterranean Sea
  • Weather report Mediterranean Sea (in German), Weather situation and forecast valid for 24 hours.
  • Alborán – Tunis. Weather situation and time series forecast for 2 days
  • Weather report Eastern Mediterranean Sea (in German). Route Eastern Tunis – Rhodes/Cyprus. Weather situation and time series forecast for 2 days
  • Medium range weather report Mediterranean Sea (in English), Weather situation and time series forecast for 5 days
  • Around the North Sea and the Baltic this service is a useful supplement to NAVTEX. Particularly so are the 5 day outlooks, These give wind forecast every 12 hours for the 5 day period. The values are straight from the DWD NWP model at a few grid points although these are sufficient to give an overall view and much quicker to receive than synoptic charts on radio fax.

In the Mediterranean, most valuable is the 5 day forecast which seems to be used and very highly regarded by the majority of serious cruising yachtsmen. It is a most valuable service for predicting the major strong wind systems such as Mistrals, Libeccios, Tramontanes, etc. Such winds are usually well predicted 4 and often 5 days ahead. Conversely, I have never found the 24 hour forecast to be much use. For this period, the French, Spanish and even the Italian NAVTEX broadcasts are to be preferred.

Modern Amateur Radio Hobby – An Introduction

This video is an introduction to an international public-service and technology hobby known as ‘amateur radio’ (or ‘ham radio’).

[embedyt] https://www.youtube.com/watch?v=K40HpIjDLRs[/embedyt]

Amateur radio (also called ham radio) describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication. The term “amateur” is used to specify “a duly-authorized person interested in radioelectric practice with a purely personal aim and without pecuniary interest;” (either direct monetary or other similar rewards) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.).

The amateur radio service (amateur service and amateur-satellite service) is established by the International Telecommunication Union (ITU) through the Radio Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual stations licenses with an identifying call sign. Prospective amateur operators are tested for their understanding of key concepts in electronics and the host government’s radio regulations. Radio amateurs use a variety of voice, text, image, and data communications modes and have access to frequency allocations throughout the RF spectrum to enable communication across a city, region, country, continent, the world, or even into space.

Amateur radio is officially represented and coordinated by the International Amateur Radio Union (IARU), which is organized in three regions and has as its members the national amateur radio societies which exist in most countries. According to an estimate made in 2011 by the American Radio Relay League, two million people throughout the world are regularly involved with amateur radio. About 830,000 amateur radio stations are located in IARU Region 2 (the Americas) followed by IARU Region 3 (South and East Asia and the Pacific Ocean) with about 750,000 stations. A significantly smaller number, about 400,000, are located in IARU Region 1 (Europe, Middle East, CIS, Africa).

Activities and practices

The expansive diversity found in the amateur radio hobby attracts practitioners who have a wide range of interests. Many hams begin with a fascination of radio communication and then combine other personal interests to make the pursuit of the hobby rewarding. Some of the focal areas amateurs pursue include radio contesting, radio propagation study, public service communication, technical experimentation, and computer networking. But, that is just a sampling of interest areas found in the hobby.

Amateur radio operators use various modes of transmission to communicate. The two most common modes for voice transmissions are frequency modulation (FM) and single sideband (SSB). The FM mode offers high-quality audio signals, while SSB is better at long distance communication when bandwidth is restricted.

Modern personal computers have encouraged the use of digital modes such as radioteletype (RTTY) which previously required cumbersome mechanical equipment. Hams led the development of packet radio in the 1970s, which has employed protocols such as AX.25 and TCP/IP. Specialized digital modes such as PSK31 allow real-time, low-power communications on the shortwave bands. More robust digital modes have been invented and improved, including such modes as Olivia, JT65, and WSPR.

NASA astronaut Col. Doug Wheelock, KF5BOC, Expedition 24 flight engineer, operates the NA1SS ham radio station in the Zvezda Service Module of the International Space Station. Equipment is a Kenwood TM-D700E transceiver.

Amateur radio operators, using battery- or generator-powered equipment, often provide essential communications services when regular channels are unavailable due to natural disasters or other disruptive events.

This video comes to us via Canada, and is used by permission from Bernard Bouchard – / ve2sms – The original video was published on Feb 28, 2013.- Website is https://www.ve2cwq.ca/amateur-radio-club-ve2cwq/

Voici maintenant, la version complète du documentaire «La radioamateur» d’une durée de 11 minutes. On y aborde toutes les activités sur le monde de la radioamateur. Ce vidéo a été produit par le Club Radioamateur VE2CWQ / Canwarn-Québec. Pour information: https://www.ve2cwq.ca/

Connect with me at https://NW7US.us

USA Amateur Radio information: http://ARRL.org

Unexpected Surprise: What Are The Odds? ATNO DXCC

I have a story for you. All of it is true, but I have not changed my name.

Wow! I am always amazed at those moments in my amateur radio hobby when spontaneous joy is had by unexpected events.

NW7US ATNO DXCC Iran

Iran worked as ATNO DXCC 2022-APR-14

On Thursday, 14-April-2022, at about 17:30 Universal Time (UT), the unexpected occurred, and it started by accident.

I have been reorganizing my radio shack. Once I moved my main transceiver (the Icom IC-7610) from one desk to another, and had it back in operation, I left it tuned to a random frequency, in the CW mode. It was just sitting there, hissing away with the typical shortwave sounds of a frequency on which no one was transmitting. And me? I was going about reorganizing my radio shack.

After a while, I heard the start of a Morse-code CW signal; the operator was sending a CQ call–a transmission that invites a response from anyone who wishes to have a QSO with the calling station. What I heard was, “CQ CQ DE EP2ABS EP2ABS…”

NOTE: This transceiver, my Icom IC-7610, is listening with the new antennathe 254-foot doublet up at 80 feet–that was raised up into the air here at my QTH by a fine crew from Hams in the Air.

I looked up EP2ABS on QRZ dot com, because I did not know from what country/entity the EP2 prefix on callsigns belongs. I was excited to see that EP2 is from Iran!

I started answering his CQ call, “DE NW7US NW7US,” for at least ten minutes; each time he sent his CQ, I answered. Finally, I heard him answering me, “NW7US NW7US DE EP2ABS 5NN…”

I answered back, sending my signal report, “5NN 5NN DE NW7US TU

Soon after that simple exchange, he confirmed our QSO by posting our QSO to Logbook of the World (LotW).

Thus, by accident–as I had simply left the transceiver tuned to a randomly-selected frequency and stayed on that frequency listening while doing my chores–I heard the Iranian station calling CQ. What are the odds!?!?

This is my first QSO with Iran, another All Time New One (ATNO). How cool!

Note: This is a testimony to the work from the crew that did the fine work of getting this antenna installed.  Here is a video presented by Hams on the Air:

[embedyt] https://www.youtube.com/watch?v=Kr9AH7OYjrk[/embedyt]

73 de NW7US dit dit

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