Monthly Archives: April 2023

RF75A Radio

Raddy RF75A Review – Pocket Radio with Interesting Bells and Whistles

Radioddity Raddy RF75A

By Robert Gulley K4PKM

The RF75A is an interesting little radio which (currently) retails on Amazon for ~$53.00 in the States. It can also be purchased via Radioddity directly for $53–if you use this referral code, you can save $15 off a $65 purchase.

Before we get into specifics, two things are worth mentioning right off:

  1. I was asked if I would be interested in reviewing this radio by our fearless shortwave listening leader, Thomas, and the copy I have was provided to me at no cost by Radioddity directly. (I have no other affiliation with them, but have recently purchased a GMRS mobile radio from them which I am looking forward to using when I finish my review of the RF75A.)
  2. This is, as you will see from the photos I am including, a pocket radio, not to be confused with a tabletop radio or a small portable radio such as the CCRadio Skywave or similar radio. I mention this because invariably there will be folks who expect tabletop or portable quality from a radio about the size of a playing card. It is not going to happen!

Having those thoughts out of the way, the quick and dirty answer as to the quality of the radio is, I am impressed. For those who have not read anything related to my past experience with radios, I have been a shortwave listener since I was about 10 years old, and now in my early sixties. So, I have seen a fair number of radios in my time (speaking as an old codger, or is that curmudgeon?) and have even moved with the times to incorporate SDRs into my radio arsenal.

Each style of radio has its place, and a pocket radio is designed to be the ultimate in portability and space savings. As light as this shirt pocket radio is, it still manages to feel reasonably solid, and of course, it could be packed into anything one was taking along for a trip.

Size Comparison with Playing Card and Cell Phone Battery

The radio measures 2.5″ x 3.5″ x 1″. Playing card and cell phone battery for comparison.

Here are some specs from the manufacturer’s website (saving you my long-winded descriptions!):

  • APP Control SW Radio: Thanks to the app intelligent remote control and Bluetooth 5.0 features, you can enjoy the convenience of RF75A. With its intuitive user interface and powerful wireless capabilities, you can easily control your radio from your devices (support iOS, Android, and HarmonyOS systems).
  • Wider Reception Range: Listen to FM, VHF, AM, SW, and WB, and stay up-to-date with your favorite radio shows and music with this powerful multi-band receiver. RF75A has a wider range of shortwave frequencies compared to the RF750.
  • Automatic Scan and Manual Storage: You can save up to 396 stations, so you can easily access your favorite stations. Experience powerful sound and crystal-clear reception with its 9.85′ wire antenna.
  • Personal Music Player: Boost your music experience with this all-in-one outdoor audio system. With Bluetooth 5.0 feature, a 3.5mm earphone socket, and a TF card socket, you can easily connect to your personal audio devices and connect to your computer as a speaker.
  • Outdoor Companion: This one-of-a-kind radio is designed to be small and lightweight, making it ideal for travel and outdoor activities. Use the flashlight and SOS for emergencies.

What’s in the box?

  • 1 x Raddy RF75A
  • 1 x Storage bag
  • 1 x Lanyard
  • 1 x Wire antenna
  • 1 x Type-C charging cable
  • 1 x Earphone

Reception

I always like to start a radio review by either listening to AM stations first, or WWV time stations for checking out shortwave reception. In this instance I started listening to AM stations in the daytime to see what I could hear on a typical day (no storms nearby, early spring, etc.).

Living in a fairly remote area I was surprised it captured as many stations as it did, making me think the ferrite bar inside must designed well for such a small radio. Evening and nighttime listening brought in many of the usual stations with which we are familiar, particularly the so-called Clear Channel stations. What was more impressive were the many small stations I was able to pick up, not only at night, but early in the morning around 8 a.m.

Ferrite Bar- Front View

Surprisingly effective Ferrite Bar

Ferrite Bar Side view

Side vide showing the magnetic wire wrap

One in particular caught my attention as I am quite certain I have never captured them before, was WHKY 1290, Hickory North Carolina. That’s a distance of about 285 miles, received in the morning. I am only about 50 miles from Cincinnati and cannot receive some of their smaller stations on any radio! Color me impressed!

Nighttime brought stations in from several thousand miles, as you would expect, yet I was likewise impressed with this little radio’s capabilities on AM.

FM

I confess to not being much of an FM listener, but I did tune around the band for FM stations to test its ability to “lock on” to signals (as indicated by a tiny red light) and to pick up stations from quite a good distance away with clarity and good sound.

This might be a good time to mention the quality of sound from the small 3 Watt(!) speaker and bass boost from the back. Again, this is not my Sangean 909 X2 with a large speaker, nor my CC Radio EP, but it has rather amazing clarity and volume capability for such a small radio. I cranked the volume up quite high with no distortion, and even though the speaker is small, the bass boost seems to round out the sound quite nicely, avoiding some of tinny sounding speakers common in such a small radio.

Weather

The radio has coverage of the NOAA weather radio stations and it surprised me with being able to receive 4-5 stations, more than I have gotten with most other radios. All but one of the signals were crystal clear, with the fifth having some noise, but still quite intelligible.

Air Band

This radio includes the air band frequencies and amateur 2-meter frequencies (30.000-199.975 MHZ). I am usually able to receive some signals, but I am quite far away from any local airports or repeaters, so my main reception is from CVG, Greater Cincinnati Airport. While the radio scans the air band frequencies, like any other radio, it is best to find local frequencies you want to hear and program them into memory so you are not wasting a lot of time scanning dead air (these are country specific). Likewise amateur repeaters or GMRS, marine, or public service channels would be best used in memory channels except when scanning for new frequencies.

SWL

Shortwave listening is very respectable, with frequency ranges between 4.750-21.850 MHz (it does not have SSB capability). Tuning can be accomplished by pressing and holding one of the directional tuning keys for about 2 seconds, a long press scans faster. A single press of either directional button will move the frequency increment based on the band/mode chosen.

The radio also features something I have come to really like: a pause button which works not only in music mode, but also when receiving regular radio signals, activated by a quick press of the power button. The frequency is held while pause is active, and then releasing the pause with a second quick press of the power button resumes with all your setting still active.

When comparing this with another radio it was particularly useful instead of having to turn the volume down like most radios. This feature is also nice for answering a call or other interruption, and you resume right where you left off.

Sound Effects, TF Card, Audio in, Bluetooth Usage and other Errata

I have not covered these features as they do not impact radio reception, but I mention them just for completeness. All of these features are available and can be read about in the user’s manual. I will mention the flashlight feature and the emergency siren features, as these are useful for portable operation. The light is quite bright, and the siren will hurt your ears if you trip it accidentally, especially more than once. Ask me how I know!

There is a sleep timer as well as an alarm clock function, with the sleep timer adjustable by default starting at 90 minutes. Most buttons have multiple functions depending on the mode employed, so reading the manual is important for some of these features. I was able to get up and running without reading the manual initially, but some features were functional only in certain modes, so eventually you will need the manual which can be downloaded from the Radioddity site.

The App

A bit of a novelty in this size and type of radio is the Apple/Android app available to control radio functions remotely through Bluetooth connectivity. I have to say, on Android at least, the app is beautiful and I wish more apps used such a clear color scheme and large controls. Your mileage may vary based on your preferences, but I like it!

Phone App on Android

The free Phone app on an Android phone. I like the crisp, clear layout and colors, and the intuitive design.

As to function, the app gives you more information than the radio screen, such as the Bandwidth, SNR, received signal strength and the volume setting in one display. As a side note, the radio can still be adjusted at the radio, and then changes are reflected in the app almost instantaneously.

Of course, the main use for the app is to operate remotely, and the controls are easy to use, including, most importantly, direct keyboard entry of frequencies! This is always the biggest drawback to small radios without a keypad. There are instructions for using the app, but for the most part the app is laid out so well you can control the radio pretty much intuitively.

Negatives –

Yep, there are a few. When tuning with a single press each time there is some soft muting – fortunately it does not last long, but it is there. The buttons also make a clicking sound, not too loud, but it is there. If something like that annoys you, be aware all the buttons make a mechanical click.

I have noticed on several occasions that the band/mode button may stick slightly and take you past where you want to go. Not a big problem, but it does happen now and again. Of course, this could just be my unit.

Also, naturally, the buttons are small. And while I did not have much of an issue even with fairly large fingers, there were times when I pressed the desired button but also hit the one below it. Not a problem for me, but again, if you have very large fingers you may find the radio a bit tricky to navigate in some places. (This only happened on the front buttons for me, the tuning buttons are adequately spaced for most anyone I think.)

The telescoping antenna is probably the weakest point on the radio – similar to most radios, really. It is thin and could be bent easily. I had no difficulties, but I always took care to raise it gently and watched where I was moving the radio around. Then again, I do that will all my radios with telescoping antennas. Just a heads-up to be careful.

Concluding Thoughts

I like this little radio, and will probably keep it in my car for those times when I might want to listen to the radio out and about, check the NOAA weather forecast, use the flashlight, or (hopefully never need) to use the siren. The battery seems to last a long time on a charge when using the radio – I cannot speak to the MP3 drain or a prolonged flashlight/siren drain, but under normal use it seems excellent. It uses a USB-C connection like my phone, so charging is not an issue for me. It will almost fully charge in an hour; the instructions say 2 hours.

Pocket radios certainly have their niche, and I think this one does quite well in that role. If you are in the market for such a radio, I think you will be pleased, especially for the price and the addition of the free remote-control app. 73!

Click here to check out the Raddy RF75A at Radioddity.

Click here to check it out on Amazon.com (affiliate link).

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Short Video: Paul tunes in Rádio Nacional da Amazônia with his ATS25 in McGrath, Alaska

Many thanks to SWLing Post contributor, Paul Walker, who shares the following video of his open-air DX shack in McGrath, Alaska. Paul notes:

I got my iRig working and recorded audio of Rádio Nacional da Amazônia on 11780 kHz directly from the radio into my phone and it sounds really good with such a strong signal here in ALASKA. Take a listen….

Click here to view on YouTube.

Thanks for sharing this, Paul! That does sound amazing–like a local station!

You, sir, are a true DXer! Anyone who regularly braves frigid temps to chase far-flung DX is made of some incredibly tough stuff!

Thanks for sharing, Paul!

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Alan Roe’s A23 season guide to music on shortwave (version 1.1)

Many thanks to SWLing Post contributor, Alan Roe, who shares his A-23 (version 1.1) season guide to music on shortwave. Alan provides this amazing resource as a free PDF download:

Click here to download Music on Shortwave A-23 v1.1 (PDF)

Thank you for sharing your excellent guide, Alan!

This dedicated page will always have the latest version of Alan’s guide available for download.

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Comparing the Watkins-Johnson WJ-8711 & WJ-8712 with TEN-TEC RX-340 & RX-331 receivers

Many thanks to SWLing Post contributor, Paolo Viappiani, who shares the following guest post:


The WJ-8711 & WJ-8712 vs. Ten-Tec RX-340 & RX-331 Receivers

by Paolo Viappiani, Carrara, Italy

In recent years, a renewed interest has grown in regards to the best HF receivers using “first generation” DSPs, typically the HF-1000/HF-1000A, WJ-8711/WJ-8711A and WJ-8712 models by Watkins-Johnson and the RX-340 and RX-331 models by Ten-Tec. Even today, the aforementioned receivers are considered among the best performers of all times; this is a well-deserved fame in the case of the W-Js, a bit less with regard to the units manufactured by Ten-Tec, a firm that once had a good reputation but that has been recently acquired by a new owner (who sold the old facilities by transferring the company and distorting the sales, support and assistance policies of the previous company [2]). I therefore believe that this article serves as a dutiful information for the readers who are potentially interested in these receivers.

A Bit of History

In the years between the last and the present century, two receivers very similar to each other in terms of design and structure were released almost simultaneously by Watkins-Johnson of Gaithersburg, Maryland [1] and by Ten-Tec of Sevierville, Tennessee [2]: the WJ-8711 (later upgraded to the A and A-3 versions and followed for a short period by the HF1000 and the  HF1000A  “civilian” versions [3]) and the Ten-Tec RX-340; both of them are shown in Figure 1.

Figure 1: The WJ-8711A (above) and Ten-Tec RX-340 (below). Notice the similarity of the front panels of the two radios.

The WJ-8712/WJ-8712A and the Ten-Tec RX-331 receivers were released by their respective manufacturers in that period also (the latter one was preceded by the RX-320 and RX-330 models). All these types were nothing more than “black-box” units, that in all respects corresponded to the WJ-8711A and to the Ten-Tec RX-340 receivers but that had not been provided with true front panels, as they were controlled by special hardware interfaces or from a PC, look at Figures 2 and 3.

Looking at the appearance of the WJ-8711/HF1000 receiver series and of the Ten-Tec RX-340 units, a relative similarity to each other is evident, and it has led to various speculations regarding the design of both devices.

One of the theories was revealed by James (Jim) C. Garland W8ZR of Santa Fe, New Mexico [4], about which he claims to have obtained information from a Ten-Tec employee directly. James claims that in 1991 the US Government Agency NSA (National Security Agency), which used to purchase numerous HF receivers for surveillance and interception, decided that the current cost of the receivers were too high and formed a special group in order to study how to obtain a possible price reduction.

At that time the high-end HF receiver market was dominated by a few manufacturers: Watkins-Johnson, Racal, Cubic, Rockwell-Collins and a few others, and Ten-Tec applied for joining the group.

Figure 2: The WJ-8712A (above) and Ten-Tec RX-331 (below). While the Watkins-Johnson model is two rack units high and half wide, the Ten-Tec develops less in height (only one rack unit) and more in width (standard 19” rack). However, both receivers are quite deep (more than 20”-50 cm.).

Figure 3: The Tmate unit of the WoodBoxRadio is shown here; it is one of the possible accessories which, together with a PC monitor, allow using the “black-box” receivers via an RS-232 interface.

According to the information provided by Jim Garland, the Watkins-Johnson and the Ten-Tec designers worked together for about one year in order to agree on the technical characteristics and guidelines of the “radio of the future” which must meet all the requirements that the NSA requested.

Continue reading

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Can you hear that sound coming from the West?

Hi SWLing Post community Fastradioburst23 here letting you know in what direction Imaginary Stations will be going in this Sunday 9th April 2023 at 2200 UTC on 9395 kHz via WRMI.

In one word we’ll be going WEST, there’ll be some Westbound trains, themes from Westerns and some spoken word from Adam West. So get your compass out, tune in your shortwave radio and enjoy everything westward (and even something Clint Eastwood related) from 2200 UTC on Easter Sunday.

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Radio Waves: AM in Ford Commercial Vehicles, History of Hornby Site, A23 DRM Broadcast Schedule, and AM Radio Importance and Action

Radio Waves:  Stories Making Waves in the World of Radio

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 Paul, and Dennis Dura for the following tips:


Ford to drop AM radio in new models, except commercial vehicles (Detroit Free Press)

Ford Motor Co. plans to stop putting AM radio in new gas-powered and electric vehicles beginning in 2024, including the all-electric Mustang Mach-E and F-150 Lightning pickup, the Detroit Free Press has confirmed.

“We are transitioning from AM radio for most new and updated 2024 models,” Ford spokesman Wes Sherwood told the Free Press. “A majority of U.S. AM stations, as well as a number of countries and automakers globally, are modernizing radio by offering internet streaming through mobile apps, FM, digital and satellite radio options. Ford will continue to offer these alternatives for customers to hear their favorite AM radio music, news and podcasts as we remove amplitude modulation — the definition of AM in this case — from most new and updated models we bring to market.”

Commercial vehicles will continue to offer AM radio because of longstanding contract language, Sherwood said.

Drivers often turn to AM radio for live traffic updates and weather reports, as well as emergency communication. [Continue reading…]

The history of the Hornby AM radio site, our oldest operational transmission site (CBC/Radio-Canada)

Did you know that one of our AM radio stations can also be used as a bunker? What’s more, the opening of this station was of such importance that King George VI addressed the nation during its inaugural broadcast in December 1937? Considered an engineering feat in its time, the Hornby AM radio site is the oldest transmission site owned and operated by CBC/Radio-Canada. Here are some interesting facts.

Listen to the King’s First Empire Christmas Greeting:

A little bit of history

Located in Hornby, Ontario, this AM radio site was built in 1937 for the CBL radio service (the ancestor of CBC Radio One) one year after the creation of CBC/Radio-Canada. The station contained a 50-kilowatt transmitter and a 640-foot tower, making it the tallest structure in Canada from 1937 to 1954. That’s more than twice the height of Big Ben (Elizabeth Tower, London).

Already a technological feat in itself, the site then added a second radio service (CJBC) in 1944 and became one of the rare AM sites to broadcast two services from one tower. The joint CBL-CJBC signal was so powerful that people could hear the program simply by putting an ear on nearby wire fences.

All about the bunker

Between 1946 and 1948, Canadians were seeing the beginning of the Cold War and, with it, the threat of nuclear attacks. As a result, the site underwent a “wartime expansion” during which the existing underground bunker, a reinforced underground shelter built for protection, was installed. Continue reading

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What does the “Beat Cut” function actually do?

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

The video below started with a curious investigation of a mysterious button found on 1980/90 era cassette recorders…. just to end up as being essential knowledge that we probably never had back on the day during our listening sessions.

I think the blog readers will love the most recent video from VWestlife:

Click here to view on YouTube.

Thank you for sharing, John!

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