Tag Archives: Jack Dully

Jack finds that chokes have a huge impact on switching power supply noise

These “Wall Wart” type adapters can create a lot of RFI

Many thanks to SWLing Post contributor, Jack Dully, who writes:

I was putting some things in my radio junk parts box and came across some chokes. So I tried a test with my Tecsun PL-880 on battery and the Tecsun supplied switching AC adapter, with and without chokes on the adapter.

WOW!

I tuned to a vacant station on battery power with headphones on. Then on AC power, the hash and static were incredible. Putting one large choke on the adapter power cord, wrapped about four times and it decreased considerably. So I attached a second choke and once again the static & hash decreased even more, almost to the point of sounding like I was running just on battery power.

Those chokes really do work well.

Thank you for sharing this, Jack. I almost never operate my portables while connected to a power supply, so I often forget about the importance of using a choke with inexpensive, lightweight radio power supplies. Thing is, so many things in our houses and shacks are powered by these QRM generators. In the shack, I’ve added chokes I’ve picked up at hamfests to a number of various power supplies. It does certainly help decrease the noise level. I’ve even used them on power cords for other appliances in the house that tend to spew RFI.

If you ever find a deal on chokes at a hamfest or electronics store, grab some. They can be an affordable solution for those noisy power supplies we still rely on.

Thank you for the reminder and  tip, Jack!

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Shortwave portables, external antennas, overloading, and electrostatic discharge

Many thanks to SWLing Post contributor, Jack Dully, who writes:

I am just wondering what portable receivers are more susceptible to overloading with long dipoles, say 60-70 ft.

I regularly use such and I have never noticed anything unusual happening with a Sony ICF-7600GR, Grundig G3, or PL-880 to name a few. I just ordered a Tecsun 680. Perhaps many of the newer radios have better AGC thresholds or more robust front ends but I really don’t know for sure.

[Also] how exactly do you know if your receiver (portable OR not) is being overloaded by too big of an antenna (ie. dipole, inverted V and the like) and will it damage your receiver? Is there still a way of using a large antenna to capture more distant stations safely, especially with good quality portables?

Thank you for sharing this question, Jack, and my hope is that SWLing Post readers can chime in with details and advice in the comments section of this post.

These are deep topics, but I’ll try to answer a few of your questions…

First of all, you definitely can harm a portable radio by hooking it up to a large antenna. Many portables have no means of protecting themselves from ESD (Electrostatic Discharge). By hooking a portable up to a long wire antenna, you can expose it to ESD which will essentially deafen your radio until you’re able to repair it. Indeed, this reminds me of an article from our archives regarding a Tecsun PL-600 ESD repair. Some radios do have built-in ESD protection (like the PL-680), but I’m not entirely sure it would offer protection from a particularly strong ESD pulse.

Symptoms of overloading can vary. Sometimes overloading can sound like background splatter and even popping. Sometimes you’ll hear “images” of broadcasters across the bands; muffled audio of a blowtorch station. Another sign of overload is when your signal meter jumps at the same time your receiver goes deaf. It’s as if your radio is simply overwhelmed by strong signals and it can manifest itself in odd ways especially since the AGC usually falls apart.

Like you, I’ve found that my Sony ICF-7600GR seems to be able to handle large wire antennas with no discernible overload.  Also, the Tecsun S-8800 (above) is well-equipped to handle larger external antennas and even sports a proper antenna port on the back. I know Sangean ATS-909X owners who only use their radio with an external wire antenna and have excellent results.

Some portable radios are very sensitive with the built-in whip antenna, but fall apart if attached to a long wire antenna.

In general, the cheaper the radio, the less likely it has a front end and filtering that can cope with overloading.

Overloading advice?

Please comment with your experience regarding overloading. Have you found some radio models better than others at coping with blowtorch stations, for example? What do you do to protect your receivers from electrostatic discharge when hooked up to large antennas? Please comment!

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Tecsun PL-990 in stock again

Many thanks to SWLing Post contributor, Jack Dully, who notes that the Tecsun PL-990X is back in stock at Anon-Co. Click here to check out their ordering page.

In addition, Tecsun Radios Australia is offering free shipping today (Friday 13, 2020).

If you’ve been considering purchasing the PL-990 or PL-990x, I’d encourage you to check out the following posts and reviews:

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MFJ’s Origins

Many thanks to SWLing Post contributor, Jack Dully, who writes:

MFJ has gone through a metamorphosis with their marketing and I thought that some radio readers might find this brief origins of MFJ interesting!

From their September 2020 Newsletter:


MFJ: Labor of Love

October, 1972.

Richard “I am not a crook” Nixon was our country’s president, The Dallas Cowboys beat the Miami Dolphins in Super Bowl VI, The Godfather was released to cinemas, George Carlin is arrested in Milwaukee, Wisconsin for uttering his ” Seven Words You Can Never Say On Television” comedic routine, Bobby Fischer defeats Boris Spassky in a chest match in Iceland, and in the small college town of Starkville, Mississippi a young Martin Jue started MFJ Enterprises, Inc., while still teaching at Mississippi State.

Martin F. Jue built this company back in 1972 with his bare hands. There were no other employees besides himself and he had a full time teaching job at Mississippi State University. The CW-F2 was his first product. It came about through a love of ham radio and in particular Morse code.

Since it is the day after Labor Day we thought we would salute the gentleman that brought us where we are today, The World Leaders in Amateur Radio Accessories! Without Martin Jue’s undying love and hard work for his namesake business, we all wouldn’t be enjoying our years here. MFJ has never had a major layoff or shutdown for any reason. 48 years later from Martin Jue’s single man company, we own four other businesses, have a tremendous product line and some of the most wonderful folks building ham radio toys under MFJ Enterprises, Inc.

Thanks again Martin Jue for your Labor of Love, MFJ the business. We are all grateful to you to be a part of your very successful venture into the world of business and ham radio. Your labor of love is greatly appreciated!


The CW-F2

Produced in October 1972, the CW-F2 was designed for the big boat anchor rigs of the time to help in CW filtering. The CW-F2 could separate two CW signals and make for more enjoyable listening. Mr. Jue used to give extra credit to his students if they helped build some of these.


The MFJ-998RT

Look at how far we have come! SMT, modern metal punching and forming machines. Here are the insides of the modern MFJ-998RT, legal limit automatic remote antenna tuner.


We salute all laborers out there for a job well done, especially our front line doctors, nurses, police officers, our US military, and Army National Guard during these crazy times. We appreciate you and our many customers! God Bless You All!

BTW — If you want to build your own modern CW-F2 kit today, the product is still alive on our Vectronics kit line as a CW audio filter kit.

P.S. VEC-820K is very similar to the first product of MFJ. A CW Audio Filter kit that you can have fun building yourself and relive a little history of MFJ!

Click here to visit MFJ.


Thank you for sharing this, Jack! 

MFJ does something that few other US manufacturers can do. They still keep the majority of their manufacturing in Mississippi and they have a solid warranty. You can even reach a human being in customer service and they repair or replace their own gear. They do this while keeping their prices very competitive.

Their gear must be the most widely used here in the States. You’re hard-pressed to find a ham who hasn’t purchased from MFJ.

Their founder and president, Martin Jue, is a top-shelf fellow, too. I’ve met him a number of times. He’s an inspiring guy with an amazing story. His employees love him, too, because he’s fully invested in his company, his community and his hobby. His company has virtually no churn at all–most of his employees have been with MFJ their entire working career.

Last month, I was very proud to add MFJ as a sponsor of the SWLing Post.

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Radio Waves: Radio Six on Shortwave Again, ATN Refrains from Politics, NPR Ratings Drop in C-19, and Grand Central’s Role in Standard Time

A WWV Time Code Generator

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 Michael Bird,  John Figliozzi, and Jack Dully for the following tips:


Radio Six Pops Up Again on Shortwave (Radio World)

Radio Six International has not been a full-time shortwave broadcaster for some time. But after two recent live broadcasts on 6070 kHz prompted by the pandemic, it says it will continue monthly broadcasts at least for now.

Radio World visited electronically with Tony Currie.[]

WLW’s America’s Truckin’ Network To Refrain From Political Talk (Radio Insight)

iHeartMedia News/Talk 700 WLW Cincinnati has eliminated political talk from its overnight “America’s Truckin’ Network” show hosted by Steve Sommers.

The Cincinnati Enquirer reports that Sommers told listeners of the change on Monday morning’s show after multiple unspecified complaints.

In the on-air statement, Sommers blamed the change on a group of individuals who took offense with comments made by a caller a few weeks ago.[]

NPR Radio Ratings Collapse As Pandemic Ends Listeners’ Commutes (NPR)

Broadcast ratings for nearly all of NPR’s radio shows took a steep dive in major markets this spring, as the coronavirus pandemic kept many Americans from commuting to work and school. The network’s shows lost roughly a quarter of their audience between the second quarter of 2019 and the same months in 2020.

People who listened to NPR shows on the radio at home before the pandemic by and large still do. But many of those who listened on their commute have not rejoined from home. And that threatens to alter the terrain for NPR for years to come, said Lori Kaplan, the network’s senior director of audience insights.

“We anticipated these changes,” Kaplan said. “This kind of change was going to take place over the next decade. But the pandemic has shown us what our future is now.”

Commercial radio is experiencing, if anything, worse declines. But audience research commissioned by Kaplan indicates that NPR’s audience is disproportionately made up of professionals who are able to work from home and who are interested in doing so even after the pandemic subsides.[]

The Day That New York Had Two Noons, a Century After Losing 11 Days (Untapped New York)

New York’s history has included everything from transit strikes to riots over Shakespeare to immigration from nearly every country in the world. Yet, for much of this history, people didn’t always know the “correct” time or date. Until 1883, virtually every place in the country set local time according to the sun. According to Sam Roberts in his book Grand Central: How a Train Station Transformed America, “Typically, noon would be regularly signaled so people could synchronize their clocks and watches.” From dropping a ball down a flagpole in Manhattan to ringing a gong, settlements all across the country would alert people of noon. But as railroads spread throughout the country, it was nearly impossible to standardize the time.

“A passenger traveling from Portland, Maine, to Buffalo could arrive in Buffalo at 12:15 according to his own watch set by Portland time,” Roberts writes. “He might be met by a friend at the station whose watch indicated 11:40 Buffalo time. The Central clock said noon. The Lake Shore clock said it was only 11:25. At Pennsylvania Station in Jersey City, New Jersey, one clock displayed Philadelphia time and another New York time. When it was 12:12 in New York, it was 12:24 in Boston, 12:07 in Philadelphia, and 11:17 in Chicago.”[]


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