Category Archives: Radios

Guest Post: “Tinkering with History”

Many thanks to SWLing Post contributor, Bob Colegrove, who shares the following guest post:

Tinkering with History

By Bob Colegrove

One of the attractive aspects of radio as a hobby is that it has so many specialties to channel our time. Just for the sake of classification, I would group these into two categories, listening and tinkering. I think the meaning of each category is fairly intuitive. Probably few of us approach our interest in radio in the same way. Most of us have dabbled in more than one listening or tinkering specialty. Perhaps we have been drawn to one particular area of interest, or we may have bounced around from one to another over a period of time. I know the latter has been my case.

Tinkering might start with a simple curiosity about what makes the radio play, or hum, or buzz, and progress to an obsessive, compulsive disorder in making it play, hum or buzz better. Unfortunately, over the past 30 years or so, the use of proprietary integrated circuits, as well as robotically-installed, surface-mounted components have greatly short-circuited what the average radio tinker can do. For example, I have noticed a lot more interest in antennas over that period, and I think the reason is simple. The antenna is one remaining area where a committed tinker can still cobble up a length of wire and supporting structure and draw some satisfaction. But the complexity and lack of adequate documentation have largely kept newer radio cabinets intact and soldering irons cold. Bill Halligan knew you were going to tinker with his radios, so he told you how they were put together. The fun began when you took your radio out of warranty. If you did get in over your head, there was usually somebody’s cousin not far away who could help you out. The following is a sample of how one resolute tinker managed to overcome the problem of locked-down radios in the modern age. Continue reading →

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Guest Post: Comparing the Reuter Pocket and the Icom IC-705 from an SWL’s perspective

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Many thanks to SWLing Post contributor, Uli (DK5ZU), who shares the following guest post:

SWL with a Reuter Pocket and the Icom IC-705

by Uli (DK5ZU)

Some time ago I asked how the IC-705 performs on longwave and I got some great feedback. Thanks a lot again. Since the HAM bug bit me again, I wanted to do SWL and HAM Radio portable with one rig. I started with SWL some weeks ago (just before the bug bit). I acquired a second hand Reuter Pocket RDR 51 Version B2. It is a standalone SDR Receiver 0 … 30 MHz / 50 ..71 MHz, and in my B2 version it has also FM (Stereo/RDS) and Digital Audio Broadcasting (DAB). You may find the detailed specs here:
https://www.reuter-elektronik.com/html/pocket.html

The Reuter Pocket could, at one point, be configured as an QRP Transceiver, but it is no longer supported. There is a new RDR 52 small tabletop models, which can be ordered as a transceiver, too. But due to Covid related supply chain problems and price changes for the components, the new model is currently postponed.

The IC-705 is available, though. And for portable HAM operations it is a no brainer; obviously with a high price tag, but comparable with a new Reuter RDR 52 tabletop. And since my budget for the hobby is limited, I thought about funding part of the IC-705 price by selling the Reuter Pocket. But I wanted to do a side-by-side comparison so I ordered the 705 and was able to check them both on one antenna. The goal was to compare their sensitivity and selectivity on the lower bands: BC on AM and HAM bands for SSB. I did not compare CW since I am not a CW operator.

The antenna is a MiniWhip from PA0RDT which works quite well on the lower bands.

This comparison is not at all scientific and reflects just my opinion and what I heard. But anyway, there may be some people out there interested in this. So much for the intro.

Let’s start with my overall findings. Continue reading →

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

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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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Anyone recognize this “DEER” Chinese transistor radio?

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Many thanks to SWLing Post contributor, Carlos Latuff, who writes:

I just bought this fully operational AM-only pocket radio made in China at the traditional flea market of Praça XV, in Rio de Janeiro, for only 25 reais (around US$ 4.39). It looks more like a response from the Chinese market to pocket radios manufactured in Japan in the 70s.

Maybe one of your readers has more information about this model.

If you have more info about this small AM transistor radio, please comment! Thanks for sharing, Carlos!

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

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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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Can you ID James Stewart’s receiver?

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Many thanks to SWLing Post contributor, Kim Elliott, who shares the image above which was originally posted by the Museum of Portable Sound on Twitter.

Kim is curious if anyone can ID the receiver model in this photo. I think I recognize this model, but I know there are better experts in our SWLing Post community to make a positive ID!

Please comment!

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Airspy HF+ Discovery & Shortwave Portables: Having Fun with the Airspy YouLoop!

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Many thanks to SWLing Post contributor, Bill Hemphill, who shares the following guest post:

YouLoop Antenna Fun

by Billy Hemphill WD9EQD

Like many listeners, I live in an antenna restricted community. While I have strung up some hidden outdoor wire antennas, I have found that they didn’t really perform that much better than just using the telescoping antenna with maybe a length of wire attached. The biggest problem (whether indoor or outdoor antenna) has been the high noise floor.

A few months ago I bought an AirSpy HF+ Discovery SDR receiver. I had already owned a couple of SDRPlay SDR receivers, but the high noise floor limited their performance. I had read good reviews about the AirSpy, especially its performance on the AM Broadcast band and the lower shortwave bands.

I have about 80 feet of speaker wire strung from the second floor and across the high windows in the living room. This does perform fairly well, but the high noise floor still exists.

A couple of weeks ago, I bought the YouLoop Magnetic Loop antenna from AirSpy. I gave it a try and am amazed at the lower noise floor compared to the indoor wire antenna.

Wire Antenna vs. YouLoop–some examples:

AirSpy with Wire Antenna

AirSpy with YouLoop

AirSpy with Wire Antenna

AirSpy with YouLoop

AirSpy with Wire Antenna

AirSpy with YouLoop

Dramatic reduction in the noise floor. I’ve done a lot of playing around with it and find that the YouLoop picks up just about the same stations as the indoor wire antenna does. But with the lower noise level, the YouLoop makes it more enjoyable to listen. Overall, the YouLoop is now my main antenna.

YouLoop with a Portable Radio

It works so well with the AirSpy, I started wondering if I could use it with a portable radio, like the Tecsun PL-880. But the AirSpy website has the following note:

Note: It is very likely your third party radio will not be sensitive enough to operate with the YouLoop properly. We have even seen self-documented failed attempts to build pre-amplifiers to compensate for the lack of sensitivity and/or the required dynamic range in third party radios. Use your brain, and eventually an Airspy HF+ Discovery.

Doesn’t sound like it will work with portable radios. BUT, I’m always one to try anyway.

Tecsun PL-880

Since the YouLoop has a SMA connector, I bought a SMA to 1/8” phone jack cable. Plugged it into the PL-880 antenna jack and found I had almost a dead radio. Very few stations heard. But in playing around, I accidentally touched the phone plug to the telescoping antenna and instantly got strong signals.

I did some very unscientific tests. I attached the YouLoop through the side antenna jack, did an ATS scan, then did the same with the YouLoop clipped to the telescoping antenna. Also did a scan with just the telescoping antenna fully extended.. I got some very interesting results. These were done one after the other, so there can be differences in signal fading, etc.

I have repeated the above test several times at different hours. While the actual number of ATS stations varied, the ratio between them remained fairly consistent to the above numbers.

From the above, it appears that the telescoping antenna circuit is more sensitive than the 1/8” antenna jack circuit. Maybe some attenuation is being added to the 1/8” jack since it’s more likely a higher gain antenna would be used there. Can anyone confirm that the circuit indeed attenuates thru the antenna jack?

The YouLoop seems to be a decent performer when directly clipped to the telescoping antenna. While not as good as a high gain outdoor antenna would be, it definitely is usable for indoor uses.

I also tested it clipped to the antennas of some other portable receivers. Tecsun S-8800, PL-330, Panasonic RF-2200 and Philco T-9 Trans-World receivers. All showed an increase over just using the telescoping antenna.

Some interesting notes:

The Tecsun PL-330 saw the same reduction in signal when directly plugged into the antenna jack as opposed to clipping on the telescoping antenna.

The Tecsun S-8800 did not show that much of a drop. I basically got the same number of stations when clipped to antenna as when I connected to the BNC jack:

In conclusion, I find that I can use the YouLoop with my portable radios to increase the signals on strong stations when used indoors. And it is quite the performer when used with the AirSpy HF+ Discovery SDR receiver. It easily portable and I find that I move it around the house as I need to. I just hang it off a window curtain rod. I may just order a second one so that my family room radio has one permanently attached to it.