LED RFI

Where we live, I have a very quiet noise floor and have enjoyed it for years. Recently, however, while operating on 40 meters, I noticed an offending signal on the Icom IC-7610 waterfall display. The noise repeated approximately every 15 kHz. If a CW signal happened to fall within the hash, I was unable to hear it.

I tried using the radio's noise reduction feature, which reduced the interference somewhat. However, increasing the noise reduction too much tends to distort CW signals, so that was not a satisfactory solution. I also tried the noise blanker, but it had no effect on the noise.

I began to think about what had recently changed in our home. Sure enough, my wife had recently purchased an LED light for her sewing table. As a quick test, I turned off and unplugged the new light. Immediately, 40 meters returned to its normally quiet state. When I plugged the light back in and turned it on, the offending signal returned.

The new problem.

I had several Fair-Rite Mix 31 snap-on ferrites, so I installed them on the power cord near the wall wart and  where the cord connected to the light. This made only a very small difference. The LED light's wall wart was plugged into a power bar, so I also added ferrites to the power bar's 120-volt power cord. Again, there was little improvement.

Next, I dug out my trusty battery-powered Eton radio and tuned it to a quiet spot on the AM broadcast band. Extending the antenna, I began hunting for the source of the RFI. When I moved the antenna close to the LED light's wall wart, the radio burst into noise. 

I considered trying a different power supply, but the LED light required 24 volts DC and all the spare adapters I had were 12 volts. After doing some online research, I came across a Mean Well power supply that appeared to have excellent filtering specifications. I ordered the correct model from Mouser Canada and hoped it would solve the problem.

Offending wall wart.

A few days later, it arrived. I plugged it in and—wow—the offending noise was completely gone. I placed the AM radio right beside the new Mean Well adapter and found it to be very quiet. It was satisfying to track down the source of the interference and solve the problem.

The lesson learned was simple: not all power supplies are created equal. In this case, the inexpensive wall wart supplied with the LED light was generating significant RF noise, while the replacement Mean Well supply was virtually silent on the air.

40m back to normal

The new Mean Well

Take a step back in time to November 26, 1928, and take a look at what was then described as the biggest and costliest Coast Guard vessel of its era. The photograph shows the state of the art radio room aboard the U.S. Coast Guard Cutter Chelan. At the time this photo was taken, she was the newest cutter in the service, proudly anchored at the Navy Yard in Washington D.C.

Coast Guard Cutter Chelan

Constructed at a staggering cost of approximately $1,000,000 (1928 Dollars), the Chelan proved her incredible value right out of the gate. On her maiden trip, she picked up a desperate SOS signal and successfully towed a disabled schooner 1,500 miles to safety. This remarkable feat stood as a record tow for the service.

Chelan was laid down by Bethlehem Shipbuilding Corporation at Quincy, Massachusetts, on 14 November 1927 and launched on 19 May 1928. She was commissioned into U.S. Coast Guard service as USCGC Chelan on 5 November 1928.

Turbo-electric cutter, Lake-class (250-footers), built by Bethlehem Shipbuilding Corporation, Quincy, MA, at cost of $900,000 (hull & machinery), launched 19 May 1928, commissioned 5 September 1928, 2,075 tons displacement, 250ft long x 42ft beam x 12ft 11in draft, 17.5kts, armed with 1-5in/1-3in/2-6pdr (1929), 97 crew (1940).

The USCGC Chelan (WPG-45) was a 250-foot Lake-class cutter belonging to the United States Coast Guard, launched in 1928. Best known for its extensive operations in Alaska and a dramatic 1937 North Atlantic rescue, the ship was transferred to Great Britain during World War II.

Sitting at the operator station is Ensign Leslie B. Tollaksen. Tollaksen would go on to have a highly decorated military career, eventually serving as a Lieutenant Commander in World War II where he commanded a naval frigate, the USS Moberly, that helped sink a German submarine in the final days of the Atlantic naval war.

We see Tollacksen in the photo above as a fresh ensign aboard USCGC Chelan. From a genealogy page:

Tollaksen “attended the University of Washington for two years before going and graduating from the US Coast Guard Academy in New London, Connecticut. He graduated from The USCG Academy in the Class of 1927, a year early to man the ships chasing down rum runners.

As a young Lieutenant, he was assigned to the US Coast Guard HQ in Washington, DC. He helped establish “Radio Washington” the telegraph station on Telegraph Road in Washington, DC, and also served as Aid to the Secretary of the Treasury, Henry Morgenthau, Jr. (At that time, his sister worked in the typing pool for President Franklin D. Roosevelt’s White House).

Leslie Bliss Tollaksen (1903 – 1973), Also nown as,”Tolley”
Birthdate: April 13, 1903, Port Townsend, Jefferson County, Washington, United States. Death:1973 (69-70), Fort Lauderdale, Broward, Florida, United States

Leslie, about 1937 was the first US Coast Guard Officer selected for Post Graduate School at MIT.

Leslie, during WWII, and in command of the USS Moberly, sank the LAST German U-Boat U-853. U-8533 was a Type IXC/40 U-Boat, and lays on the bottom off Block Island…”

For history and technology buffs, the equipment in this radio room is absolutely fascinating. In 1928, maritime communication was undergoing a major technological revolution. Global maritime operations were beginning to phase out the older, notoriously noisy spark gap transmitters. Instead, the Chelan was outfitted with modern continuous wave vacuum tube technology. This room housed three powerful transmitters and three highly sensitive receiving sets.

If you look closely at the right side of the image, you can see the large glass vacuum tubes safely housed behind protective metal mesh doors. These power tubes allowed operators to transmit signals on specific, sharply tuned frequencies, reaching much further out to sea without causing interference for other ships. The tall black panels are also loaded with large rheostat dials for tuning, as well as precise ammeters and voltmeters to monitor the high voltages running through the system.

Meanwhile, Ensign Tollaksen has his hand positioned near a traditional straight telegraph key to send out Morse code. The receiver units he operated likely utilized regenerative or early superheterodyne circuits, giving operators the incredible sensitivity needed to hear faint SOS calls through heavy atmospheric static. It was exactly this kind of cutting edge machinery that allowed the crew to hear the distress call that led to their record breaking rescue!

USCGC Chelan was a Lake-class cutter belonging to the United States Coast Guard launched on 19 May 1928 and commissioned on 5 September 1928. After 13 years of service to the Coast Guard, she was transferred to the Royal Navy as part of the Lend-Lease Act, and named HMS Lulworth (Y60). During the war Lulworth served in a convoy Escort Group for Western Approaches Command. She returned to the U.S. Coast Guard after World War II.

USCGC Chelan was a Lake-class cutter belonging to the United States Coast Guard launched on 19 May 1928 and commissioned on 5 September 1928. After 13 years of service to the Coast Guard, she was transferred to the Royal Navy as part of the Lend-Lease Act, and named HMS Lulworth (Y60). During the war Lulworth served in a convoy Escort Group for Western Approaches Command. She returned to the U.S. Coast Guard after World War II.

Read more about this vessel: https://en.wikipedia.org/wiki/USCGC_Chelan.

Following the recent suspension of Voice of America (VOA) shortwave and medium-wave (AM) transmitters, the U.S. Agency for Global Media (USAGM) is orchestrating a gradual return to the airwaves.

Starting next week, USAGM will begin testing shortwave transmissions from the historic Lampertheim site in Hesse, Germany, which formerly served as a primary broadcasting node for Radio Free Europe and Radio Liberty (RFE/RL). This reactivation indicates that USAGM is working to restore its global broadcast capacity after surviving a period of severe operational cuts and the near-abandonment of its legacy transmission centers.

Lampertheim joins a growing list of international USAGM transmitting stations seeing renewed activity, including sites in Marathon (Florida), Greenville (North Carolina), Kuwait, the Philippines, Botswana, and Thailand. The permanent commissioning of these shortwave sites will depend heavily on the results of ongoing signal testing. The Lampertheim reactivation may ultimately serve as a temporary measure while USAGM awaits the completion of a major transmitter installation and upgrade project currently underway at the Kuwait Transmitting Station.

Built in the early 1950s during the height of the Cold War, the Lampertheim site was an RF (radio frequency) powerhouse, ruling the airwaves with eight massive 100 kW shortwave transmitters designed to pierce the Iron Curtain. Following the corporate merger of RFE and RL in 1976, the station broadcasted both services simultaneously. In 1995, under the newly formed Broadcasting Board of Governors (BBG–the predecessor to USAGM–the station became a consolidated hub for American international broadcasting.

The fall of the Soviet Union and the subsequent independence of Eastern European satellite states drastically altered the station’s mission. The target areas for Lampertheim’s massive curtain antennas were no longer geopolitical priorities, and direct shortwave programming was shrunk to almost nothing.

Instead, Lampertheim’s primary mission shifted toward technical, administrative, and logistical support. It became a vital satellite uplink and distribution gateway, beaming TV and radio programming to relay stations across Europe, Asia, and the Middle East. It also functioned as the remote-control nerve center for USAGM’s global network of transmitters, which included the medium-wave transmitter in Cape Greco, Cyprus (installed at the former RMC Middle East Transmitter Center), the strategic relay station in Djibouti, the massive 1,000 kW medium-wave transmitter in Orzu, Tajikistan, and, Technical oversight for nearly a hundred USAGM-affiliated FM transmitters globally.

During the wars in Afghanistan and Iraq, Lampertheim saw a brief resurgence in direct broadcasting as antennas were reconfigured to target the Persian Gulf and Southwest Asia, filling coverage gaps left by the Kuwait transmitters.

Today, radio enthusiasts and DXers can track the ongoing progress of USAGM’s shortwave broadcasts by consulting the HFCC A26 (Summer 2026) seasonal schedules here: HFCC A26 Schedule: https://new.hfcc.org/data/schedbybrc.php?seas=A26&broadc=AGM

AmateurLogic.TV Episode 218 is now available for download.

Major elimination of static and noise in HF radio reception using neural networks and machine learning. Sodium ion battery tests. Hurricane season preparation.

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YouTube

Here is a Press Release concerning the Colorado QSO Party. Like it says below, this is our chance to Activate The State. SOTA and POTA enthusiasts, there is a page specifically for you. Bob K0NR FOR  IMMEDIATE  RELEASE Contact: Alan Higbie – K0AV – [email protected] Colorado Hams Invited to “Activate the State” During the 2026 ... Read more

The post Colorado QSO Party appeared first on Above Average Terrain.

On Monday evening (June 15th), I was honored to be the Emcee for the Vicksburg Amateur Radio Club’s surprise program. In a previous meeting there, Malcolm Keown W5XX mentioned that he had confirmed with ARRL that he broke the all-time record for the longest continuously elected Section Manger. Malcolm had served as Vice Director for the Delta Division but was elected as Section Manager for Mississippi on March 1, 1998. He surpassed the New Mexico SM Bill Mader K8TE on April 2, 2026, making him the longest serving SM in the history of the American Radio Relay League. As I had dinner during the fellowship period before the gavel dropped, I wondered how can the Club honor this career-long record of service to both the League and to amateur radio in the Magnolia State.

Back in 2013 when George Thomas, W5JDX of Jackson MS was named the winner of the 2013 Special Achievement Award for his work on Amateur Logic TV and Ham Nation, I organized a dinner to recognize this once in a lifetime honor. (I guess there might have been a repeat winner but you get my point.) What could we do to positively recognize W5XX in this case?

So I approached my friend and VARC President Chris AF5OQ about doing a surprise program the next month. I’d find an old vinyl “record” album and bring a small hammer. Malcolm could then could literally “break a record” to symbolize his achievement. Thus, the plan was hatched!

I’ve written a more detailed rendition of the events over on the VARC website. I encourage you to click on that link and read the details. To be brief, a really good time was had by all. Here’s the specific event, captured on video. I brought along an antique ball peen hammer I inherited from my father in-law for Malcolm to use. Even though he is a retired engineer from the Corps of Engineers in Vicksburg, the look on Malcolm’s face at the very end of this video shows he’s not familiar with how the peen end of the hammer is a most effective tool, especially in metal working. A flimsy vinyl album didn’t stand a chance. Nonetheless, even as his mobility has waned since a recent injury from a fall, W5XX operates “ball peen mode” very, very well!

It was my honor to serve as Emcee for this surprise program. Malcolm was given the broken record pieces in the box set case as a momento. He told us that it would go right next to his Lifetime Membership Award from VARC that is in his shack. Here is a picture of the boxset I found at a local Goodwill Store for $0.48 which I rounded up to one dollar. It’s called, Beautiful Music, Beautiful Memories, which is highly appropriate for this event. The video clip of the key moment follows.