Category Archives: Shortwave Radio Reviews

Ivan’s preliminary review of the new RTL-SDR dongle on shortwave/mediumwave

RTL-SDR-RTL2832U-e1471375714199Many thanks to SWLing Post contributor, Ivan Cholakov (NO2CW), who shares the following video review of the new RTL-SDR dongle on the shortwave and mediumwave bands.

Ivan notes:

This is daytime reception comparison. Nighttime could be a different picture. [The RTL-SDR dongle] tunes and frequency is 100% on spot.

Using SDR Sharp you have several AGC settings to play with and find the best combination. The best setting seems to vary with band and signal strength.

The [SDR receiver] comes with a short (20 cm) and long (120cm) telescopic antennas. Neither one is usable for HF or Medium wave.

When ordering the radio you have to get a USB extension cord for the dongle. When plugged in directly into a laptop and then antenna coax it can become bulky. You also will most likely need an SMA adapter to BNC and SO 238.

I hope this helps.

Click here to view on YouTube.

Many thanks for sharing your video, Ivan! For a $25 SDR, I’m pretty impressed so far! I’m also very curious how it will hold up to stronger nighttime signals and, especially, adjacent signal interference. I imagine it may be prone to overloading as well. Please keep us posted!

Have any other Post readers tested the new RTL-SDR dongle on HF? If so, please comment! 

Francis loves the Sony ICF-SW11

Sony_ICF-SW11_4

Many thanks to SWLing Post reader, Francis, who left the following reply on our Battery Endurance Contest Results post:

Dear Thomas,

I have been using a Sony ICF-11 for 5-6 years now, still sold new at 50-70 euro. It’s analog and rather well featured: FM (stereo on earbuds), LW, AM, and 9 SW bands. It runs on 2 cheap AA batteries I get in low-cost supermarket, for sure not the best ones.

Sony_ICF-SW11_3

Using it at least one hour a day on the speaker, I have to change the batteries after 9-12 months. I am convinced a set of good Duracell or Energizer batteries would last some more months.

Sony_ICF-SW11
I am not a radio expert, but I am quite pleased with its audio performances, specially on LW (used most of the time ) and AM, where it is vastly superior to my Tecsun PL-660. SW looks OK for what I can say from listening quite occasionally these bands. I would be curious to see a serious review of this Sony to know how it compares with others, but I didn’t find any on the web so far (hint?). [Yes, Francis, hint taken!]

Sony_ICF-SW11_2
I am so pleased with this small radio that I recently bought a second one as a spare.
Thanks for your very interesting blog and reviews.
Francis

Thank you, Francis, for sharing your thoughts on the Sony ICF-SW11 and your photos as well!

It appears Amazon.com (US) has a few options for ordering a Sony ICF-SW11–click here to show search results. Prices vary between $50-$55; Amazon even has replacement telescopic whips available.

Of course, an eBay search will also uncover a number of SW11’s.

I searched the web, but couldn’t find many other retailers selling new ICF-SW11’s. It appears many of the ones on Amazon are imports from Japan.

At $50 shipped, it seems like a bargain to me, so I just pulled the trigger on one.

Bruce believes the CC Skywave is an ideal travel radio

The C.Crane CC Skywave

The C.Crane CC Skywave

Many thanks to SWLing Post reader, Bruce Atchison, who recently shared his positive comments about the CC Skywave. Bruce writes::

This is a lot of radio for such a small size. The CC Skywave is a great travel companion because of its portability and price.

Moreover, it’s rich with features. The receiver tunes in AM and FM as well as all the shortwave bands, NOAA weather channels, and the aircraft band. The latter comes in handy while you’re waiting for flights so you can find out immediately and directly what is delaying them.

It also has a built-in alarm clock so you needn’t miss the next morning’s activities.

The Skywave runs on 2 AA cells and can be set to charge NiMH rechargeable batteries. Its mini-USB port lets you use the AC adaptor or 12 volt cigarette lighter adapter. You can even use one of those cell phone solar panels to power the set.

This radio’s reception is excellent and its filters allow for eliminating adjacent channel interference. Apart from its rather high noise floor on AM, the receiver pulls in stations at night very well.

The Skywave can also add local stations to its memory pages automatically. This comes in handy in foreign cities when you don’t have time to manually scan the AM and FM dial.

This is truly a globe trotter’s accessory. You can set it to European AM channel spacing and the Japanese FM band. The radio even has a fine tuning setting for oddly-spaced stations.

The three amber LEDs light up the dial nicely and they turn off automatically after about ten seconds to conserve battery life. In fact, the Skywave is amazingly energy efficient.

Whenever I travel, this radio is one thing I’ll be sure to pack. It’s all I need when I travel away from home.

Thanks for sharing your thoughts, Bruce.  Yes, I believe the Skywave is a great little travel radio, too. One of the Skywave features I used extensively while off-grid in Canada this summer, was the weather radio function (Environment Canada and NOAA frequencies are the same). Without Internet, it was an excellent, handy source of weather information.

Paul’s review of the Kaito KA108

Many thanks to SWLing Post contributor, Paul Dobosz (K8PD) who shares his review of the Kaito KA108. Paul originally wrote this for the Michigan Area Radio Enthusiasts and has kindly allowed us to post it here:


Kaito KA-108 Review

Kaito-KA108-AM

by Paul Dobosz (K8PD)

Kaito just introduced a pocket sized DSP based MW/SW/FM receiver with some interesting features missing in other SW receivers its size. I just got my hands on one for the first time a couple of months ago and am getting familiar with its features, performance, and quirks. I first saw the KA-108 at the Consumer Electronics Show in early January when I visited the Kaito booth and spoke with Walter about their newest radios. There are no schematics included with the KA-108 and I haven’t cracked open the case but based on the functionality, size, and price point it appears that the KA-108 utilizes the now common DSP based receiver architecture found in most of the new portable radios.

First of all, a brief run down on the features and functions of this compact little radio.

  1. Compact Size –  5.5” x 3.25” x 1.1” Weight 9 oz
  2. Frequency Coverage – MW: 520 – 1710 KHz, FM: 64 – 108 Mhz, SW: 2300 – 23000 KHz
  3. Memories – 400 (100 MW, 100 FM, 200 SW)
  4. Power – BC-5 Rechargeable LiPo 3.7V battery
  5. Other Features
    • Timer/Clock radio dual alarm function
    • MP3 Timer record & playback to/from a Micro SD card
    • Standard USB port that accepts a thumb drive.
    • Exceptional Bass Response for travel sized radio
    • “Auto Store” feature will scan and store frequencies
    • Battery charging via micro USB (no wall wart to carry)
    • Audio “line In” can be used as computer or MP3 speaker

Most radios have their good and not so good points and the Kaito KA-108 is no exception. Here is a rundown on the LA-108’s “HITS & MISSES”

The HITS

This radio is small and lightweight which makes it an ideal travel radio.  The control layout features a full keyboard for frequency entry as well as up and down keys that will search for signals when held down.  The fit and finish are excellent and the keys have good positive tactile feel.  There are two rocker switches, one for volume up/down and the other for band/mode selection.  The radio comes with a decent user manual and quick start guide.  The manual’s English is a little awkward in places but is fully understandable.

The backlit LCD display is brightly lit with large white numbers on a blue background.  It is easy for older eyes to read, even without glasses.  The signal strength meter is actually fairly useful which is rare for radios at this price point.  

The standard frequency step is matched to channel spacing for the band in use with exception of the FM band which tunes in 100 KHz increments instead of the US standard 200KHz steps when the frequency range is set to the North American band.  The FM band can be set up to tune all the way down to 64 MHz if desired but since TV has migrated from analog to digital the usefulness of that coverage is minimal for North American users.  AM is 9 or 10 KHz step capable with a frequency range to match all parts of the world.  In addition to the standard frequency steps, the thumbwheel encoder can be used to fine adjust the frequency between the standard increments in 1 KHz steps.

The MP3 playback is very pleasant to listen to.  I tested it with several different genres of music with consistently good sound quality.  I haven’t tried the recording function yet but it is definitely a nice feature, especially in such a compact package.  The KA-108 has a standard USB input (not mini or micro) behind a sliding door on top of the radio for external memory devices like thumb drives.  MP3s can be played and audio recorded to/from this port as well as the Micro SD card slot aside of it.   I’m also hopeful that the USB port may be capable of upgrading the radio firmware in the field.   If not, that’s another feature that Kaito should definitely consider for future versions of the KA-108.  (More on that later)

One feature I really like is the rotary tuning thumbwheel encoder on the side of the radio.  It has a light detent feel that allows you to manually tune the radio in 1 KHz steps to easily allow you to move to one side of a signal.  Frequency entry via the numeric keyboard is straight forward and intuitive with exception of the non-standard location of the zero key to the right of the bottom row of the numeric keys.  

The FM reception is excellent with bass response that makes you wonder how such a mellow sound comes out of such a small box.  Despite the 1.5” speaker, the audio has lots of bass and lacks the “tinny “sound of most travel portables with small speakers.  It plays loudly without distortion.

MW reception was typical for a radio with limited space for a small ferrite antenna and I was able to hear the usual SWBC stations and time/frequency UTE’s on the HF bands.  SW reception using just the 20” whip was just OK with easily listenable strong signals found on most of the active SW bands 2MHz and above.  The KA-108 is AM only on the HF bands (no SSB or CW).  There are some quirks with the MW and AM reception that I’ll cover in the MISSES section of this review

The MISSES

I never thought I would complain about a portable receiver with a “too tight” a bandpass filter but the KA-108 is a first.  The bandpass filter for MW &SW are extremely narrow which when coupled with the KA108’s exceptionally strong bass response, reduces the intelligibility of the received audio on the MW and Shortwave bands.  I have been able to mitigate the situation a little bit acoustically by covering a portion of the speaker grille with my hand or placing a small tube in front of it which seems to attenuate the bass and improve the overall audio response but the audio is still lacking in the higher frequencies that make things like music and the human voice more intelligible.  

Tuning 1-2 KHz off of the carrier frequency with the thumbwheel helped improve things a little bit similar to the way you might use IF shift on a high end tabletop receiver.  I also noticed that stronger stations that have a signal that spills further down the filter’s skirts had better audio response than those that lacked sufficient strength to spill over the filter response curve. I am hopeful that Kaito will offer a firmware upgrade to open up the bandwidth.  If the USB port used to play thumb drives has hooks into the radio’s CPU then it might be possible to open up the bandwidth and improve the MW and SW audio without cracking open the radio case to re-flash the CPU or make a hardware change.  The bandwidth issue is the largest single miss for the KA-108 in my opinion

I found a few buzzes and whistles on the MW band and you can hear the CPU clock oscillator strongly at 12MHz.  I haven’t looked inside of the radio yet but I would imagine that some of the MW noise can be tamed with a bit of internal shielding.  

I also found the AGC setting to be a bit too abrupt, jumping up and down in almost a step function with a signal whose level was fluctuating quite a bit.  That’s another minor software adjustment to consider for the next edition.

Due to the KA-108’s small size, the whip antenna is rather short (only about 20”) which means the front end must have a lot of gain leaving it more vulnerable to overload.  I was able to receive a the stronger SWBC stations while sitting in the middle of my house but I also heard another faint signal under the SW stations.  The interfering signal turned out to be a local 1KW AM station on 145o KHz whose transmitter is about 4 miles from my home.  It was present in the background while listening to SWBC and was heard standalone on its 2nd and 3rd harmonics which were most likely generated internally due to the high gain front end.  The short SW antenna does create the need for higher front end gain but should be accompanied by a high pass filter behind the SW whip antenna or at least a 10dB attenuator.  Either or both of those features would reduce AM BCB intrusion while listening to SWBC.  

In the coming weeks I’d like to do some parametric measurements on the KA-108 and will also see how it behaves with a longer antenna and antenna tuner with low pass filter ahead of it.  That should be a good test to see if a simple filter can eliminate the AM intrusion.  Improvements to widen the AM/SW filter bandwidth and reduce the AM overload should be high priority improvements for the next version of the KA-108.  

Summing It Up

I found the KA-108 easy to operate as I’ve explored the AM/SW/FM and MP3 operating modes and it’s a nice sized radio for casual listening when I’m at home or to take with me as I travel for use as an alarm clock, music player, and radio in one compact package.  

The KA-108 has potential with a few software and hardware tweaks. Fixing the MW/SW bandwidth is #1.  A simple high pass filter that rolls off just above the AM broadcast band behind  the SW whip antenna is #2.  I can live with a few buzzes and tones but why not fix them with a little inexpensive shielding while adding the other fixes.  

The KA-108 will never match the performance of tabletop or lunchbox sized portables, but if you’re looking for a nice little radio that will almost fit in your shirt pocket with nothing more than a micro USB cable to tote along for battery charging, and a radio that sounds twice its size, this radio fits the bill.  I hope that Kaito will address the issues I’ve noted with future software/hardware revisions to improve the performance of the KA-108 and maybe even offer a way for current owners to field upgrade their radios.  


That’s a thoughtful and fair assessment of the Kaito KA108, Paul. It’s a reminder that, with a few strategic tweaks, the KA108 could be a great little portable. Thank you for sharing your review with us! 

Guest Post: Patrick compares four receivers

Many thanks to SWLing Post contributor, Patrick Canler who writes to us from France and shares the following guest post which he translated into English:


4 rec

The number of receivers on the market is quite large, and all are sold to be the “best”. I have thought it useful to compare materials using them in the shack as a neophyte SWL; going beyond the features in the brochures to talk about everyday utility. This article does not pretend to do “scientific” testing of the four receivers–skills and special equipment are needed and some specialized laboratories already do it.

The four receivers cover thirty years of electronics manufacturing; four different brands with their own technology and specifications. Over such period, technologies and innovations have evolved. One of the questions I had was: “Does efficiency give any receiver an advantage?”.

The Contenders:

NRD-535 from Japan Radio Company.

nrd535

A reference of the 90s! It received 5 stars from WRTH (which publishes annually the almanac “World Radio and TV Handook”). The NRD-535 has conventional construction with an electronic card per function and discrete and analog filters.

This is a home station receiver, weighing in at 10 kg. The NRD-535 ceased to be produced in 1996, and its value second hand is growing due to its reputation.

AR7030 from AOR

ar7030

Designed by the engineer who developed the LOWE receiver line, the AR7030 is also famous for its reception. It uses special ergonomics and a hybrid of software menus and conventional controls. Quite small, it is easily transportable, due its design that already uses SMC but keeps the analog filters.

IC-R75 ICOM

ICR75

Modern device, classical format and renowned–the R75 is the only receiver tested that is still in production [Note: it was recently removed from production]. It uses CMS, combines analog and DSP filtering (the DSP option is present on the device under test). Its ergonomic design is intuitive and so too are controls and menus.

1102S RADIOJET Bonito,

SDR windows

The 1102S RADIOJET is the only unit in this comparison that is produced in Europe!
The Radiojet includes the latest developments in technology, its performance is simply stunning on the data/spec sheet. The application includes many tools (spectrograph, digital filters, IF and AF recorders, decoder, list of broadcast stations, etc.). It brings together all the SMC receiving electronics in a small box that can fit in a pocket.

SSDR box

The commands and tools are assigned to a software (highly evolved) that runs on the PC which is connected the SDR. The power of the PC also brings graphics, memory, recordings etc.

Why these four rigs?

In the beginning, and it was it which led me to be SWL, I acquired the RADIOJET based on its announced characteristics: sensitivity of “secret services”, adaptable to all cases with filters, graphics tools–“Star Wars equipment” is not it! Later I learned about 50 MHz and at the same time I was struggling to exploit the Radiojet SDR.

A good opportunity to purchase an ICOM R75 brought me back to conventional radio ergonomics. As time passed, I felt my listening skills improved with these 2 receivers and the receiver syndrome grew! A Kenwood R5000 joined the others for its VHF potential and HF reputation.

Then I discovered an NRD-525 on Ebay at a fair price point (rare)–it joined the group of receivers. The latter two were sold and replaced respectively by an AOR 7030 and by NRD-535. I really enjoyed the 525, but the 535 is even better.

In use, the RADIOJET and R75 have always posed problems with settings and sound quality. Kenwood reassured me about the fact that we could get some nice reception without fighting against the controls. validated by the AOR, the NRD 525 & 535. Perhaps I did not understand the manipulation of digital filters???

Now to the shack!

The four receivers are placed side by side, but arranged so as not to disturb each other (eg. the display of the ND535 disrupted the RADIOJET).

The antenna is a 25m random wire oriented East/West with 9:1 balun and its own ground. The passage from a receiver to the other is done by a conventional antenna switch.

All the tests were performed in one evening for constant conditions, there was a fairly present QRM which, was not too bad for comparison purposes. The tests were made in SSB or AM. Preliminary tests had shown that the results in digital modes (PSK31, JT65, ..) relied more on the decoder performance of the PC rather than the receiver. The tests increased from the lowest frequency detected this evening (Europe 1-163 kHZ) to the highest (Foreign Broadcast =15,545 MHz).

The highest frequencies, up to 30 MHz, were deserted in phone, at least for my installation.
The procedure was:

  1. Signal is detected from the spectrograph SDR: it typically “sees” almost inaudible signals.
  2. The candidate frequency is tuned on all four receivers
  3. I listening to all of the signals on all receivers, seeking to get the maximum performance, using all possibilities (notch, passband, IF Shift, integrated amplifiers, attenuator, etc.)
  4. Results are reported in the table below.

One can notice rather quickly:

  • that age is not a handicap
  • the number of functions is not always an advantage
  • 1102S RADIOJET
    Performance and capabilities above the rest (on paper) and requires being connected to a PC. At the present time, on an old Celeron 2Gb ram, the RadioJet’s application never saturated the CPU. The band spectrum display allows one to find the QSO, to filter theoretically perfectly, but it does not always equate to the understandability of the signal or give a pleasant audio. And the number of software features and functions complicates the signal manipulation. The sound is still a little metallic, perhaps due to the signal processing software. Its small size makes it a unbeatable mobile receiver for travel, functions are incredibly useful for those who master the RadioJet application.
  • AOR AR7030
    Inherently simpler at face value–the AR7030 is ultra easy to use. It makes it easy for the user to find and tweak a candidate signal. It’s intuitive and has essential functions only. It has well-designed electronics. The AR7030 is also best receiver tested for handling strong signals without overloading (broadcasts stations or nearby hyper-kilowatted amateur radio operators) which seems to prove that it is designed for these stations. Its limit is the lack of adaptive notch filter types to clean the noise, which is still quite present when the QRM is there. (The newer version 7030+ has added features to help). Finally, it is the smallest stand-alone, portable and with 3 options of antennas connections.
  • ICOM R75
    The R75 climbs up the frequency band all the way to 50 MHz, the only receiver tested with this frequency range. It enjoys an excellent reputation, and can be equipped with a DSP (digital signal processing) on audio. The DSP provides adaptive noise reduction and automatic notch, but has a relative effectiveness which is not always successful in clarifying the signal. Sometimes it adds an unpleasant “rattling”. In use, the interface is pretty intuitive–mixing commands by buttons and menus. Twin pass band tuning (PBT) is effective and allows for IF Shift and/or notch. The speaker is (very) small and gives an aggressive/harsh sound. This receiver is relatively small in size and lightweight. It has a mobile stand and is designed for a 12-14V power supply.
  • JRC NRD-535
    The NRD-535 is the oldest tested–indeed, it was already discontinued before the other receivers were in production. A solid and reliable construction, good ergonomic with conventional front panel controls, good sensitivity, and a decent sized speaker have earned it status as a benchmark in its time. Very sensitive, it extracts the signals and, once found the right filter, gives it pleasant audio. Some signals are not completely cleaned but it does rarely less than others. The NRD-535 is designed for home use: it is heavy, almost 10 kg, and is contains several circuit boards which should not be too exposed to excessive shocks, especially considering they’re over 20 years old.

Summary

My ranking is as follows:

  1. JRC NRD-535 for its ease of use and ability to dig out a usable signal from the QRM.
  2. AOR AR7030 for its simplicity, portability and the fact that it extract good sound/audio quickly, even if a little noisy at times.
  3. Bonito RADIOJET for its small size and its extensive feature set. It is ultra-mobile with a laptop.
  4. ICOM R75 does the job and covers a wide frequency range. But lags in performance relative to the other receiver tested, with a “nasal” sound and a DSP that does not keep its intended promises.

About digital filters: the SDR and ICOM have them, the possibilities are extensive and allow adaptive filtering that others do not with analog filters. By cons they give a dry sound and sometimes add “snap” under whistles. Listening is overall less pleasant in comparison.

Receivers Advantages + / Disadvantages –

Bonito RADIOJET
+ Top technology, visual and many new features over the others on this point
– Complicated, metallic sound, emphasizing the sometimes painful receiver interaction with a computer mouse

Icom R75
+ Great value at the present time
– Audio and imperfect signal cleaning

AOR AR7030
+ Simple and effective
– Ideal companion if it had a notch filter: noise is present

JRC NRD-535
+ Effective sensitivity and clean audio
– Older technology, less portable

Note that this is a personal opinion: a computer geek will certainly get the most of performance and possibilities from an SDR like the Bonito RadioJet.

The NRD-535 shows its age, will one day reach the end of its useful life despite its robust construction. ICOM can cover up to 6m remaining mobile and has a good filter possibilities (DSP). The AOR is easy, fast and gives a correct listening, general purpose. It is the only one to pass the VLF.

The ideal then?
* RADIOJET for sensitivity,
* The RADIOJET for tools/features and functions
* AR7030 for the lower bands
* Icom for the higher bands
* NRD-535 for ergonomics
* AOR for portability

Personally, I use the NRD-535 for DXing (due to superior audio), the AR7030 for digital modes,
the RADIOJET to visually search for signals, and to sometimes clarify the signal even better and because it’s ultra-mobile and always in my PC case.

73,
Patrick F61112


Thank you, Patrick!

I should mention that I think you did a fine job translating your article into English for us! I would not be as successful writing an article in French!  

I’ve never owned a JRC of any sort. If I ever found an NRD-535 for a good price, I would purchase one without hesitation. I’ve never spent much time on the AR7030 either. It’s simple “Lowe-like” front panel is quite appealing for field use. I found that the RadioJet audio is quite nice when paired with a good set of headphones.