Category Archives: How To

Guest Post: Crystal Radios – Construction, Listening, and Contesting

Many thanks to SWLing Post contributor, David Day (N1DAY), for sharing the following guest post:


Crystal Radios – Construction, Listening, and Contesting

By David Day – N1DAY

The date was November 2, 1920 and the world was about to change forever when radio station KDKA out of Pittsburgh PA made its first broadcast of election results from the 1920 presidential election.  For the first time in history people knew who won the election before reading about it the next day in the newspaper.  Radio had arrived!

However, hearing the election results was not as easy as powering up an AM radio receiver because radio electron tubes had only been invented a few years earlier and they were still too expensive for most people to afford in a radio set.  After KDKA’s historic broadcast, large 50,000 watt stations began popping up in all major cities around the world.  Even though a tube-driven radio was not yet commonplace, many people listened to these stations on their crystal radios.  The frenzy around radio in the 1920’s was not unlike the excitement around cell phones and the internet today.  If you didn’t have one, you were simply living in the past.

A family listening to a crystal radio in the 1920’s

Fortunately, in the early 1920’s the crystal radio had been around for a while and it was easy to make or purchase a completed set on a limited budget.  The beauty of the radio was that it was a passive device needing no power source other than the radio station’s broadcast that was received by a good antenna about 50 feet long and 15 or so feet above the ground.  Crystal radios derived their name from use of galena crystals as detectors. Continue reading

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Abbree AR-F8: Rolf’s mod to achieve zero volume

Many thanks to SWLing Post contributor, Rolf, who writes:

Hello Thomas,

I have a Abbree AR-F8 portable.

It had a small problem: the volume would not get to zero, so you hear still hear noise if
the volume knob was on low/zero.

I opened the radio and found a solution. Continue reading

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The Gift That Keeps On Giving: Pavel’s Amazing Upcycled Hombrew Radios!

Many thanks to SWLing Post contributor, Pavel Kraus, who shares the following guest post:


Inspiration for gifts

by Pavel Kraus

This article should be just an inspiration for how to make a gift for our wives and neighbors so that they are not upset that we are still sitting at the radio, but rather they also have something to do with it.

When I see a nice box, I get the thought of building a radio in it.

Iomega ZIP Drive Radio

For the production of the first two radios, I used boxes from Iomega ZIP floppy disk drives, which were previously widely used in DTP studios before the advent of USB flash drives and can certainly be found as discarded in warehouses.

Used electronic components can be purchased on eBay, Amazon, Aliexpress – they are radio modules, batteries, charging module, other components can be found in our amateur stocks.

After removing the inside of the Iomega ZIP drive, there is room for the module to be built in and the transparent window prompts you to place the module with the display.

I desoldered the encoders from the motherboard and placed them on the side of the radio. The fingerboard of the button from the drive can also be used as a power switch.

At the same time, the original LEDs can be used as an indication of charging the built-in battery.

In the second type of radio using the same box, a button control module is used, where the buttons have been desoldered and connected to a separate board inside the radio.

Russian Enclosure Radio

The third type of radio uses a box from Russian radio by wire, where an AM / FM radio module with a clock was built in.

Commodor C 64 Power Supply Radio

The last type uses half of the box from the Commodor C 64 power supply. It has a built-in radio module with IO SI 4732 (radio from the Commodore C64 power supply box with SI4732 radio module .jpg).

A photo of my wife is printed on the radio panel so she doesn’t say I’m looking at foreign women.

I wish you all a beautiful and relaxing Christmas, all the best until the new year 2022 and a lot of inspiration for radio hobbies.

Pavel Kraus

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Guest Post: Pavel’s Homebrew “Monster” Drain Pipe FSL Antenna


Many thanks to SWLing Post contributor, Pavel Kraus, for the following guest post:


Building a Drain Pipe FSL Antenna

by Pavel Kraus

Hi, I greet all DX fans and the entire SWLing Post community! I enjoy reading reading this blog and the diversity of contributions from our authors and contributors; many thanks from me for so much useful information.

The following are the construction notes of my FSL antenna, which I designed thanks to the suggestions of GaryDeBock, and other FSL designers.

The antenna is a classic design featuring 60 ferrite rods 200x 10 mm, which are placed on a plastic sewage pipe.

Pict 3: Pipe with ferrite rods and windings

Pict 4: Pipe with ferrite rods and windings

In addition, sewer pipe sections are used for the entire antenna cover. I assume that this material can be obtained in other countries as well. Continue reading

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Jason seeks advice about hazy PL-680 LCD screen

Many thanks to SWLing Post contributor, Jason, who writes:

Hi Thomas,

Recently I was cleaning and foolishly decided to clean the face of my Tecsun PL680 with 90% iso alcohol using an ear cleaner / Q-tip. Now the LCD has a smudge look to it, almost like a fog. The display is still legible thankfully, but only when looking head on. I quickly wiped it down with a cloth and left it in an airtight container filled with silica gel packets for a week.

Would you or other SWLING readers have any idea how to remedy this? It is my understanding that this is just cosmetic damage and shouldn’t impact the usage of the radio.

Regards,

– Jason

Sorry to hear about this, Jason. Yes, isopropanol/isopropylalcohol is a solvent and can corrupt plastic surfaces like this. I’m familiar because my wife once tried to clear a DVD with 90% isopropylalcohol and it made the surface so hazy, the DVD player could no longer read it. I don’t think this will have any impact on the radio itself since you didn’t exactly did it in iso alcohol.

I understand that in some cases, polishing the surface can minimize the haziness, but how to do that, I’m uncertain. My hope is, another SWLing Post contributor can chime in with some real-life experience!

Please comment if you can help Jason!

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Giuseppe’s Homemade “Magic Tablet” Antenna System

Many thanks to SWLing Post contributor, Giuseppe Morlè, who writes:

Dear Thomas,

This is Giuseppe Morlè, from Formia central Italy on the Tyrrhenian Sea,

I built this “Magic Tablet. during a rainy afternoon to test various portables I have.

The tablet is composed of 2 separate circuits: one for the short waves, a single coil along the entire perimeter of the tablet, and another with 2 ferrites wrapped around 36 turns of telephone cable for the medium waves.

The heart of the system is a 1050 pf variable capacitor with its old wheel.

To listen to medium wave I have to exclude the short wave loop with a switch on the loop.

I also added another small switch to connect it to a capacitor for more or less capacity, but this I will do later.

I can test my portables like this because the tablet tunes very well from 500 kHz to 18 MHz. I spent very little to make all this as it is all recycled stuff.

You can see the first tests on the balcony of my house with a Tecsun H-501 via my YouTube channel:

Note: this video is in Italian, but you can turn on closed captions and have it translate into the language of your choice.

As I always say, I am not a technician and I have little manual skills in building things, not having a proper laboratory. When I get an idea, I put it on paper and I start to find all the materials and then see if they work. Not all of us are of the experts in electronics–what drives me is a passion for radio listening. Now being retired, I have more time to devote to it.

Thanks to you and hello to the whole SWLing Post community …

73. Giuseppe Morlè (IZ0GZW)

I love this, Giuseppe! What a clever all-in-one portable antenna system for your shortwave radios. I especially love the fact you were able to create all of this from parts you have at your home. You’ve got a winning attitude, too: build and experiment!  Thank you for sharing.

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Jock explores “The Essential Listening Post”

Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:


The Essential Listening Post

By Jock Elliott, KB2GOM

Listening to shortwave radio (or any radio, for that matter) is just plain fun.

So what do you need to get in on the fun?

A radio. With today’s crop of portable SW radios, many of which have search and store capabilities, a newbie SWL can get started quickly without a lot fuss and bother and no extra stuff. Just hit the search and store function (it has different names on different radios), let the search function do its thing, and step through the memories to see what’s out there. If your radio doesn’t have search and store, you can just tune around to see what’s currently broadcasting or, if you have a computer or smart phone, use it to explore one of the online directories like https://shortwaveschedule.com/

What follow next are some things that I’ve found increase my enjoyment of SWLing. Continue reading

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