Category Archives: Ham Radio

Ian’s portable setup for SSB and maritime weather monitoring

6 Replies

Photo by Jonathan Smith

Many thanks to SWLing Post contributor, Ian, who shared the following response to our post regarding the best shortwave receiver for you boat or yacht:

An icom M802 package can be had for less that $3k… but the installation may run up anywhere up to $5k hence the OP’s ~$8k cost and request for alternatives. The bulk of cost (for pretty much anything in a boat) is always in installation…not the cost of electronics, as boats have unique issues regarding their ground.

As a sailor, when faced with a budgetary issue of installing a marine SSB radio system, IMO the answer is most definitely not “get a ham radio and your license”…the answer is most definitely “get a good SSB portable with an external antenna input”.

To get valuable weather resources such as Chris Parker (www.mwxc.com), weatherfax and eavesdop on atlantic nets, a quality portable SSB receiver is all that is required, provided that some sort of external antenna is used.

In my case, in the Bahamas, a 25ft length of wire semi permanently rigged to the flag halyard presented a strong and clear enough signal to reliably get the morning weather, and any weatherfax data I needed (along with the laptop).

My radio back then was the Satellit 800, and this year that behemoth will be replaced with a Tecsun PL-880… such a setup is ALL that is required.

Thank you for your input, Ian! It’s been seven years since we originally posted that article about HF receivers and transceivers on boats and yachts. I’m curious if any other readers might have suggestions they would care to share. What has works for you? Please comment!

A compact homebrew Si5351-based SDR

8 Replies

(Image source: Circuit Salad)

Many thanks to SWLing Post contributor, Paul Evans, who writes:

I see this receiver as a remarkable break through. Using audio processor to emulate modes from IQ is very, very clever. This is perhaps the article of the year!:

(Source: Circuit Salad)

[…]This is a revised version of my FV-1 based SDR. I replaced the CS2100 clk generator with the Si5351 clk generator. The Si5351 has some advantages over the CS2100, namely you can generate quadrature clks directly. This simplifies the hardware design and improves the quadrature accuracy. The sideband rejection in LSB/USB modes is impressive..somewhere around 60 db as best I can measure. The DSP processing is accomplished by the use of a FV-1 audio processor. The device makes the base band signal processing a snap. It requires some code to be loaded on a EEprom but the circuitry is simple and allows for up to 8 selectable programs. I created three: AM/USB/LSB . The FV-1 provides for three analog POT inputs to control any parameters you choose. Gain, variable filter bandwidth and depth, AGC are some examples of adjustable parameters if you desire. I kept it simple and created fixed band pass filters to taste. I did use one of the controls for AF gain. The design has no tuned circuits or band pass filters but they could easily be added.  It works just fine without them. Occasionally, I come across a ghost signal from harmonic mixing, when tuning, but not enough to matter. The design uses an OLED display and a rotary encoder for tuning. The frequency coverage is from 2.7 Mhz to 25Mhz. The bottom limit is created by the inability of the Si5351 to support quadrature below this frequency. Although I have improved my DSP programs for the FV-1 and have developed new display drivers and the new code for the Si5351, useful detail about using the Fv-1 can be found in my original design from a few years ago: https://circuitsalad.com/2015/06/19/comming-soon-stand-alone-software-defined-radio-baseband-demodulator-no-computer-required/

The design uses a LTC6252 low noise op amp as an RF input with gain. It provides a constant and reliable resistive Rf termination for the sampling detector.  This allows for random antennas to be used without adversely affecting the input termination to the detector. All the code to operate the main processor(display/clk generator/tuning, band select and receive mode) was written in MikroC which is a C compiler for PIC and AVR processors. The generation of quadrature signals out of the Si5351 is not difficult to implement once you know how but..figuring that out took me a couple weeks of experimentation! You can connect switches, the encoder, volume pot and display directly to the main board for operation but I created a secondary board to mount the display and encoders. Instead of an analog pot and selection momentary switches, I used another microcontroller and two encoders(with one built in momentary push switch each) to create all of the switching signals, gain control, etc. This allowed me to have just two controls for all features.  The controls include: tuning, audio gain, mode, and tuning step. Tuning resolution is from 1Hz to 100KHz . For fun, I made the output of the FV-1 differential into the audio amp. This is not necessary.

Here is a link to all the files used to build this radio in a zip file(updated 1/18/20):

https://www.adrive.com/public/Fq3pNr/Si5351%20SDR%20Data.zip[…]

Demo video

Click here to read the full article, download all design notes/files and watch videos at Circuit Salad.

Wow–that is fascinating! Thanks for sharing, Paul. I’m curious if any SWLing Post readers have experimented with the Si5351.

Interestingly, SWLing Post friend Dave Richards (AA7EE), also recently shared this video of an amazing Si5351-based VFO built by JF3HZB:

This must be one of the best analog emulations I’ve seen on a display. Marry the SDR receiver above to this VFO and you could have a top-shelf homebrewed receiver!

Troy finds Tenergy Centura low self-discharge batteries a great value

10 Replies

Many thanks to SWLing Post contributor, Troy Riedel, who recently shared his observations about low self-discharge batteries with me. He has kindly allowed me to post his message here on the SWLing Post. Troy notes:

I’ve lauded Tenergy rechargeable NiMH batteries and I wanted to share something with you.

Mighty Bright Navigation Light

I have a box of Mighty Bright combination Red & White LEDs that I use for astronomy (they’re a clip-on light used by pilots and also marketed for use in the automobile – they hold three AAAs).

Approx. 18-months ago I put fully charged Rayovac, Energizer, Eneloop & Tenergy Centura Low Self-Discharge batteries in them.

Last night I pulled them out.

Rayovac: 0% charge.
Energizer: 0% charge
Tenergy Centura LSD & Eneloop: both averaged ~ 70% of a charge … (6 batteries in two lights) … though some of the Eneloops had a slightly higher charge (maybe 2 – 5% higher), most of the batteries were virtually indistinguishable.

You can buy 8 Tenergy for $9.99 while 8 Eneloop cost $17.99.

If cost were not an issue I’d still go with Eneloop (a longer track record), but the Tenergy is a worthy – no, very worthy – value vs. performance choice.

Panasonic Eneloop batteries

Thanks for sharing your real-world feedback, Troy.

I’m a big believer in low self-discharge rechargeable batteries. Indeed, I’ve almost replaced all of our “legacy” (meaning not low self-discarge) NiMH AA and AAA batteries with Eneloop cells.

Eneloops are pretty pricey, though, and the costs add up if you have a lot of devices that require batteries. As you might imagine, portable radios demand a steady supply of AA batteries at SWLing Post HQ.

I’ve been very pleased with my Eneloop batteries and, frankly, haven’t switched brands because of the terrible luck I’ve had with “legacy” rechargeables in the past. I’ve purchased so many that worked wonderfully for a few months then began to lose their capacity even though I employ an intelligent charger that properly breaks-in and cycles them.

I do believe I’ll add some Tenergy AA and AAA batteries in the mix now–especially for non-radio applications like lighting, remotes, clocks, and other consumer electronics.

Click here to check out Tenergy batteries and click here to check out Eneloop batteries at Amazon.com (affiliate links support the SWLing Post).

What are your observations?

Have you used Tenergy and Eneloop batteries? What about other brands?  Please share your thoughts by leaving a comment on this post.

Radio Waves: Capitol Code, Clay’s Corner, The Buzzer, iHeart Layoffs, and Australian Hams

2 Replies

Radio Waves:  Stories Making Waves in the World of Radio 

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors, William Lee, Stana Horzepa, Rich Cuff, and Marty for the following tips:

Capitol Records Building Morse Code (WA1LOU)

This iconic Los Angeles landmark has been emitting secret messages since it opened. However, only those with a keen eye for Morse code can decipher what they say.

It was the former president of Capitol Records, Alan Livingston, who got the idea to have the light on top of the building send out a signal in Morse code. The word chosen for this secret message was “Hollywood.” When the building opened in 1956, Samuel Morse’s granddaughter Leila Morse had the honor of turning the light on.

Read the rest of the story at Atlas Obscura.

Clay’s Corner February 2020 Edition (Northwest Broadcasters)

Some are interpreting this as meaning that – every – AM will be switching to digital leaving a Jillion AM only receivers with nothing to listen to (except for electrical gizmo noise). I give more credit than that to the owners of AM Radio Stations. I would highly doubt if any market would see all of their AM’s go digital. Perhaps in an ownership that had two AM’s it might make sense to have one of each.

[…]Other question is, what will the company that owns HD Radio (EXPERI) want to extract from the owner of an AM station that’s willing to put everything on the line and go all digital?
The bottom line is there appears to be a lot of interest in this proposal. The FCC’s process will likely draw a number of comments, pro and con. This will be an interesting process to watch. I can say one thing, never did I ever dream that we would be debating this issue![…]

Seven mysterious sounds science has yet to solve (Popular Science)

The Buzzer

Numbers stations—shortwave radio transmissions of monotone coded messages—are inherently creepy. But call sign UVB-76 has outcreeped them all by playing the same jolting tone from Russia since 1982. Similar broadcasts are useful for sending messages where snoops might intercept digital comms, so “the Buzzer” could simply assist spies. But it plays far fewer words and digits than confirmed espionage outlets, so some suspect it’s a science project that bounces radio waves off the ionosphere to detect solar flares. The most intriguing theory posits that it’s a doomsday device that will go silent should Russia suffer a nuclear attack, thus triggering retaliation.

My theory is that these mysterious sounds are actually the intro to a Pink Floyd song, possibly from their 1969 album Ummagumma. Because the early Floyd albums, before Dark Side of the Moon, are no longer heard on-air, the Russians stole this music knowing we’d never notice. Ooh, gotta go… I hear the black helicopters coming…[…]

iHeartMedia laid off hundreds of radio DJs. Executives blame AI. DJs blame the executives. (Washington Post)

When iHeartMedia announced this month it would fire hundreds of workers across the country, the radio conglomerate said the restructuring was critical to take advantage of its “significant investments … in technology and artificial intelligence.” In a companywide email, chief executive Bob Pittman said the “employee dislocation” was “the unfortunate price we pay to modernize the company.”

But laid-off employees like D’Edwin “Big Kosh” Walton, who made $12 an hour as an on-air personality for the Columbus, Ohio, hip-hop station 106.7 the Beat, don’t buy it. Walton doesn’t blame the cuts on a computer; he blames them on the company’s top executives, whose “coldblooded, calculated move” cost people their jobs.[…]

Amateur radio skills prove useful during bushfire emergencies (ABC News)

Amateur radio enthusiasts have proved themselves useful during the recent bushfires after traditional telecommunication channels broke down.

Amateur radio, also known as ham radio, is a skill and international hobby whereby enthusiasts use specific radio frequencies to communicate with each other.

In Australia, users must complete an exam to obtain a license through the Australian Communications and Media Authority (ACMA).

It was volunteers with these skills who were called in to assist during the recent New South Wales bushfires.

Neil Fallshaw is vice-president of WICEN NSW Communications, a group of volunteers with amateur radio licenses who can help in emergency situations.

He said about 30 members provided a temporary radio system in the Bega, Cobargo, Narooma, and Bermagui areas after some of the local radio infrastructure was damaged or had lost power.

“We deployed one of our radio repeaters on the mountains. We put a radio repeater system on that mountain to cover a portion of the south coast,” Mr Fallshaw said.

He said that radio system assisted the NSW Volunteer Rescue Association and Bega Valley Shire Council staff to communicate from bushfire-affected towns like Bermagui and Cobargo.

“They normally use just mobile phones, but the mobile phones in the area were down because of fire damage,” Mr Fallshaw said.[…]

Mike Ladd’s primer on decoding NAVTEX using an SDRplay SDR with SDRuno

5 Replies

Many thanks to SWLing Post contributor, Mike Ladd with SDRplay, who shares the following PDF primer on decoding NAVTEX with an RSP series SDR.

Click here to download “Basics to decoding NAVTEX using an RSP and SDRuno” (PDF).

Thanks for sharing this excellent guide, Mike.  Without a doubt, SDRplay has some of the best documentation and primers in the world of radio. Click here to check out more.

Also, check out Mario’s post, from our archives, which discusses decoding NAVTEX, RTTY, and Sitor B.

Radio Waves: New BBC Ham, Russian Propaganda, Rotators, USB Continuity, and a Moment of Silence

4 Replies

Radio Waves:  Stories Making Waves in the World of Radio 

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’sRadio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors, Marty, Mike Terry, and Tracy Wood for the following tips:

BBC World Service presenter is a radio amateur (Southgate ARC)

Gareth Mitchell M7GJM is well known as presenter of the BBC World Service show Digital Planet. He got his amateur licence in 2019 thanks to help from members of Essex Ham

Since getting his licence, Gareth M7GJM has been mentioning amateur radio in his BBC World Service show, most recently, featuring how radio hams in Australia have been helping with emergency comms.

Read the Essex Ham story at
https://www.essexham.co.uk/news/online-learning-and-exam.html

Information on the free Foundation Online course that Gareth took is at
https://www.essexham.co.uk/train/foundation-online/

Russian ‘Propaganda Machine’ Selects Kansas City As Its Second Radio Broadcast Site (KCUR)

Commuters interested in conspiracy theories about George Soros, Hillary Clinton and the Republican National Committee have a new option, courtesy of the Russian government.

Early this month, a radio station based in Liberty, Missouri, signed a three-year deal to broadcast Radio Sputnik across Kansas City.

The English-language programming airs for three hours each morning and again in the evening on three frequencies controlled by KCXL: 1140 AM, 102.9 FM and 104.7 FM.

It’s produced by the U.S.-based branch of an organization created in 2013 by Russian President Vladimir Putin to promote Russian interests abroad.

The organization, Rossiya Segodnya, hopes to restore a “fair attitude to Russia in every country in the world,” according to court records.

For now, Radio Sputnik only broadcasts in two American cities: Kansas City and Washington D.C., where its programming has aired since 2017.

“We’d love to broadcast in all major U.S. markets,” a Radio Sputnik spokesperson told KCUR via email. “But unfortunately, U.S. authorities are working really hard to prevent us from doing so.”[…]

Rotators – How do you turn that thing? (Nuts and Volts)

We’ve had a few columns on antennas and propagation, and there sure is a lot of variation in the types of antennas! All the different ways signals propagate require different antenna directions and types. Hams use dinky finger-sized “rubber ducks” on handheld radios but also some ridiculously big antennas it seems. Hams can’t use as much power as some of the other communication services, so they use antennas to get through by focusing radiated power.

If the antennas can focus a signal, then they need to be able to focus it in the desired direction, right? A few antennas can do that electrically by controlling the signal’s phase or switching antenna elements on and off. Most of the “pointable” ham antennas, though, need to be pointed mechanically and held in place during a contact or to keep a communications link working. The thing that hams use to point their antennas — large and small — is called a rotator.

There are a wide range of rotators, just like antennas. You may have used a TV antenna rotator with its “chunk-chunk-chunk” stepping. At the other end of the scale, whole towers turn! We’ll cover some of the most common types and give you an idea of how they work. (If you want detailed information, including guidelines and illustrations for how to work with these unsung heroes of the antenna farm, see the sidebar, “Rotator and Tower Know-How.”)

Build a USB continuity jig (Nuts and Volts)

If you’re like me, you likely have a drawer or shoebox stuffed with assorted USB cables that are used to either charge or program a USB device. The problem often is that some cables may only be useful for charging, and which only have the +Vcc and ground wires intact with one or both data wires either broken or not connected in the first place.

Every Radio Station in Los Angeles Holds Moment of Silence for Kobe Bryant (Billboard)

Los Angeles has been rendered speechless by the shocking death of NBA legend Kobe Bryant, his 13-year-old daughter Gianna “Gigi” Bryant, and seven others in a helicopter crash in Calabasas, Calif., on Sunday morning. And for one minute and eight seconds — the extra time nodding to Bryant’s original No. 8 Lakers jersey — radio stations across the city held a moment of silence Monday (Jan. 27) at noon.

The Southern California Broadcasters Association asked its members to synchronize their moment of silence, as well as continuously airing reminders about the upcoming tribute.

Before noon, the SCBA requested all local area radio stations to repeat this core introductory message for grieving Angelenos listening in: “Right now All LA radio stations are now broadcasting 1:08 minute silence for LA Sports Legend Kobe Bryant,” according to an announcement posted on the association’s website.[…]

Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

FCC approves kickoff of 5G 3.5 GHz band grab

8 Replies

Photo by Joshua Anderson Slate

(Source: FCC via Paul Evans)

For Immediate Release

FCC AUTHORIZES FULL COMMERCIAL DEPLOYMENT IN
3.5 GHZ BAND, ADVANCING AMERICAN 5G LEADERSHIP

WASHINGTON, January 27, 2020—Federal Communications Commission Chairman Ajit Pai today announced that the agency has certified four Spectrum Access System (SAS) Administrators, paving the way for full commercial operations in the 3.5 GHz band. Last year, the FCC approved these SAS Administrators for initial commercial deployments. Today’s action allows for full commercial use of this critical mid-band spectrum for broadband connectivity and 5G.

“The FCC has made it a priority to free up mid-band spectrum for advanced wireless services like 5G. And today, I’m pleased to announce the latest step to achieve that priority: the approval of four systems that will enable the 3.5 GHz band to be put to use for the benefit of American consumers and businesses,” said Chairman Pai. “As with all of our efforts to execute on the 5G FAST plan, we’re pushing to get next-generation wireless services deployed in the 3.5 GHz band as quickly and efficiently as possible. I would like to thank Commissioner Mike O’Rielly for his leadership throughout this proceeding as well as the FCC staff and those in the private sector who have worked so hard to achieve this milestone.”

To view today’s public notice certifying CommScope, Federated Wireless, Google, and Sony as Spectrum Access System administrators in the 3.55-3.7 GHz band, please visit https://docs.fcc.gov/public/attachments/DA-20-110A1.pdf.

###