Kaito KA2100 AM/FM Radio

I purchased this Kaito KA2100 radio in 2007 for $100, and used it on and off for the last three years.  The KA2100 is version of an AM/FM/SW (shortwave) radio made in China by Redsun Electronics Co. Ltd. as the Redsun RP-2100.  The Kaito KA2100, also made by Redsun, is almost identical to the RP-2100 with the exception of the mains power supply, but was sold in the United States through a different distributor.  Although no longer imported into the United States, a very similar (though not identical) model is now sold by C. Crane Company as the CC Radio-SW. 


Features
The KA2100 is what is referred to today as a 'lap portable' (large-size portable) radio.  It uses a large LCD display featuring a dual-time clock as well as broadcast frequency and other information.  Fit and finish of the cabinet seems good, with no obvious manufacturing or assembly issues.  Controls are large enough for convenient use, and the radio has a built in carry handle that has proved adequate for the purpose, if a bit flexy.  The whip antenna can be extended to its full length and canted directionally without flopping over.  The speaker grille is made of metal, not plastic, and the various switches and pushbuttons have a fairly solid feel to them, with the exception of the two band selection controls, which feel a little vague and rubbery.  At around five pounds when loaded with batteries, it is rather hefty, and its relative narrowness for its height (no prop stand is provided) makes it a bit tippy if the radio is accidentally bumped.   

When powered off, the LCD display gives the current local time, and with the push of a button, World Coordinated Universal Time (UTC).  Either can be shown in 24-hour (military) format.  The clock feature facilitates its use with short wave broadcasts from around the world, which are generally scheduled according to UTC times.  Since the radio easily receives U.S. NIST broadcasts of the F1 Atomic Clock time on shortwave from WWV in Fort Collins, Colorado (and often WWVH in Hawaii as well, though I live in Arizona), the clock can be manually set to this time, though automatic synchronization or a fast 'hack' to the NIST-F1 is not provided.  When powered on, the indicated broadcast frequency is displayed.  There are lights to illuminate both the LCD display and the various pushbutton controls.

Rotary knobs are used to adjust frequency, RF gain (amplifies the signal of faint stations on AM and SW), volume, treble and bass tone, while four-position rotary switches control band selection (AM/FM/FM Stereo/SW1/SW2/SW3) as well as wide or narrow AM/SW filters.  The digital tuner can be set at to scroll at either a fast or slow rate as needed when moving through various bands.  In addition to the rotary tuning knob, pushbuttons allow you to page through each band in steps.  Backlight and snooze buttons are mounted on top of the cabinet.  There is also a travel lock button to prevent the unit from being accidentally powered on while traveling.

FM is tunable through 87.00-108MHz (megahertz), AM from 520-1710KHz (kilohertz), and SW (shortwave) in three continuous-coverage bands from 1711-29999KHz.  Two IF filters are provided, 6KHz (narrow) and 12KHz (wide) to improve selectivity between stations broadcasting on frequencies adjacent to each other.  A slider switch inside the battery compartment optimizes the radio to receive AM broadcasts in either 10MHz (USA) or 9MHz (Europe) steps. 

When you reach the end of a frequency range of a given band, the radio gives off a loud and rather unpleasant ‘beep’.  You also get one 'beep' every time you press a pushbutton on the control panel.  Fortunately, these can be turned off by holding the snooze button down for a couple of seconds while testing any control panel button to verify that the 'beep' has been turned off.

While the KA2100 can receive both monaural and FM stereo broadcasts, the radio itself has no integral stereo capability (such as found on a twin-speaker boombox); instead, one must attach headphones or amplified dual speakers to receive FM stereo. 

As a standard analog-broadcast model, the KA2100 is not capable of receiving the digital portion of HD Radio broadcasts.  Nor can it receive the single-side-band (SSB) transmissions used by ham radio enthusiasts or the U.S. Navy's Armed Forces Network.  It also cannot be upgraded to receive U.S. digital satellite radio broadcasts, such as Sirius XM.  However, it does have a 455KHz AM IF output using a PAL port, which can be utilized to attach a separate SSB modulator to enable the radio to decode transmissions used in many ham radio broadcasts.  I have one of these SSB adapters mounted on a printed circuit board (PCB), and its modulation control is touchy and difficult to tune.  However, once adjusted it works fairly well, translating the 'Donald Duck' sound of SSB broadcasts into understandable voices.  The same PAL IF port will also accept a DRM decoder for receiving Digital Radio Mondiale (European digital radio) broadcasts through a home PC.          

Fifty stations or discrete frequencies may be pre-programmed into the internal memory, ten on each waveband.  These may be selected by using a pushbutton to page from one stored frequency to the next.  Additional slider switches control battery type (both AA and D size batteries can be used), local/distant AM station reception, and internal or external antenna use.  The radio is also fitted with an buzzer, sleep timer, and snooze switches in order to function as an alarm clock/radio.  It can be fitted with stereo headphones or its RCA outputs can be utilized to feed an external stereo amplifier and speakers in lieu of the built-in monaural version.    

The KA2100, as with some other more modern shortwave portable and lap portable radios, employs dual-conversion synthesized PLL (Phase Locked Loop) technology to improve image rejection (an image station is one that appears on one or more frequencies besides its actual frequency, thus impairing or blocking reception of other stations broadcasting on the real frequency).  It has two built-in antennas: a large internal ferrite rod for AM reception, and a 44” long telescoping, hinged whip antenna for FM and shortwave.  Additionally, there are both 75/50-ohm PAL and high-impedance wire-feed spring clips on the rear of the cabinet for attaching feed inputs from various external antennas. 
        
Power options are especially numerous on the KA2100.  This is intentional, as it was designed as a radio for worldwide distribution that could be successfully operated anywhere, particularly in remote areas.  Unlike its cousin the RP2100, the KA2100 has a shielded A/C power supply and DC transformer built into the radio (no buzzing 'wall-wart' required), and thus can be powered directly by standard 120-volt household current using the supplied power cord (a 240v supply would require a separate RFI-protected step-down transformer).  If for some reason you lose the power cord, it can also use a 9v, 500mA AC/DC power supply (wall-wart) with a negative central polarity plug (not included).  It can operate on either four ‘AA’ or four ‘D’ standard (lithium, alkaline) batteries (all eight batteries are carried simultaneously, and AA or D size selected to power the radio by means of a slider switch).  Or you can install NiMh rechargeable batteries (either size) instead, and the standard built-in charger (A/C power cord or 8+ volt separate DC power supply required) will recharge them when the radio is not in operation.


Operation and User Experience

Pros
For a $100 portable radio with a single speaker, the sound quality of the KA2100 is very good to excellent, aided by the fairly large five-inch speaker and tone controls.  The internal 120v power supply is shielded to prevent radiated RFI (radio frequency interference) that could otherwise impair signal reception.  

Battery life is good to excellent.  I have used both standard alkaline (1.5 volt) 'D' and rechargeable NiMh (1.3 volt) AA batteries in the KA2100.  Operation is good with either type of battery, as is battery life – I’ve used the radio intermittently for as long as two weeks using just the rechargeable AA batteries.  However, when I installed a set of four NiCad 'D' rechargeable batteries, I found their voltage output too low to achieve best operation.  I'm not sure if the problem was due to the voltage curve/output of the NiCad cells, or for some other reason.  However, given that a set of standard 'D' alkaline batteries lasts 54 hours in continuous operation, it probably won't be an issue to most people.     

Reception on all bands is amazing, given the cost of this unit.  It has a powerful built-in tuned ferrite rod antenna for directional AM reception, and at night I regularly pick up powerful stations 1,200 miles away, and weaker ones (5 kw or less) from half that distance.  By turning the entire radio, reception quality to a given station can be maximized.  At times, two AM stations on the exact same frequency with known transmitter locations (say Denver and San Francisco) can be heard by this method, using the radio as a crude direction finder.  For a built-in antenna used inside a home with block walls and bounded by mountains on two sides, I consider that above-average performance.  I’ve attached a roof-mounted AM external wire antenna occasionally to the KA2100's high-impedance AM external antenna connectors (the internal antenna is not disconnected when this is done), but reception was only modestly improved, leading to me to think that the built-in ferrite rod antenna is a fairly strong performer.

FM reception using the attached whip (telescoping) antenna is excellent, and the tuner is of high quality.  I had no problems understanding broadcasts from FM stations 101 miles away, though with some background static noise.  FM performance is so good, in fact, that I was unable to improve upon it when I temporarily connected the KA2100 to a dedicated, roof-mounted FM antenna. 

Shortwave reception is equally outstanding.  After unpacking the radio and installing batteries, and while using the provided long whip antenna, I pulled in readable-to-strong voice and music broadcasts on shortwave from Radio Turkey, Radio Sweden, Voice of Russia, China Radio International, Radio Taiwan, Radio Japan, Radio Australia, and various Arabic-language stations, all from inside my home.  While SW stations using North American repeater (relay) stations were stronger, I could often receive broadcasts at night from much further away - for example, Radio Sweden came in with clarity whether broadcast from the repeater in Sackville, Canada, or the towers in Hörby, Sweden. 

Drift is minimal to non-existent on SW bands, and non-existent on AM and FM.  The 1KHz 'slow' rate digital tuning is helpful when nailing down stations.  The narrow 6HKz filter is effective for reducing background static and improving audibility of both AM and SW broadcasts under certain conditions.  It is also most useful when blocking off a an adjacent (but undesired) station with a more powerful or over-modulated signal.

During the initial evaluation, substantial radio static interference was encountered from the photocell mechanism on my outside dusk-to-dawn light, which was turned off.  The radio also doesn't like nearby dimmer switches - again, one must turn them off.  A buzzing noise over the power line caused by a whirling electric fan that was keeping me cool was solved by simply unplugging the A/C power cord from the radio and operating on batteries.  The motion detector lights and dimmer switches used by next-door neighbors had no apparent effect whatsoever.     

Some months later, I tried looking for the BBC, which had ceased broadcasting to the U.S. on shortwave at some point.  However, by picking up their broadcasts to Africa on the KA2100, I was able to hear the BBC News Service with good signal and audio quality.  By attaching the radio's 50-ohm PAL port to a roof-mounted short-wave wire antenna, I have even picked up the paranoid ramblings of the Voice of Korea (Radio Pyongyang) from North Korea as well as an obscure low-power station broadcasting the time in Spanish from South America.       

The arrival of digital satellite radio and live internet feeds have made shortwave broadcasts a thing of the past for some radio listeners.  However, I find the KA2100 is admirably suited to bringing in news stores and features from other countries that I might not read or listen to if I were simply using the internet.  You can set this radio up in the living room, bedroom, or campsite and listen passively to the news of the world and learn while going about your other activities.  From the KA2100 I first learned I would not be getting any more coffee beans from Zimbabwe for awhile.  How Australian aborigines travel in a desert environment.  That some nations still broadcast secret code 'spy-vs-spy' messages to agents abroad.  And how the gender of your Japanese language teacher may affect your pronunication and resultant first impression on native speakers.         

Cons
The owner’s manual is rather poorly written in halting or ungrammatical English, and it is fairly brief.  It sufficed for me, though a person unfamiliar with shortwave radios might have a few difficulties in translating the directions.

The KA2100's add-on SSB detector is clumsy and finicky to tune.  It should have been made integral with the radio. 

The travel lock button, which is pressed for two seconds to unlock the unit, is not protected by a protruding frame or bump guard of any kind.  This raises the possibility that the unit could be accidentally unlocked and powered on while being transported inside locked luggage.  

While the radio's dual-conversion technology does mostly prevent images on the shortwave bands, it is not completely free of 'ghosting', i.e. the appearance of a few powerful or over-modulated AM radio stations in the lower shortwave bands.  This could be overcome by better initial stage selectivity, or the addition of a selectable high-pass AM filter on the shortwave bands.    

Setting the clock can be a frustrating experience, and requires constant reference back to the owner’s manual.  This is in part caused by the radio’s multi-function pushbutton controls, which set additional functions through use of timed delays; after a few seconds, they revert back to their original function.  Setting the time successfully requires an alert and dexterous operator.  The clock on my radio tends to run a bit fast (gains time).  Automatic coordination with the NIST's WWV time broadcasts would have been a welcome addition.  

The external FM/SW port for attaching an external antenna uses a PAL antenna port commonly seen in Europe, but not readily found in most US stores.  Though the radio came with a couple of PAL connectors to fit the port, I had to find an adapter from a specialty ham store to adapt it to a coaxial cable feeding a roof-mount antenna.  A screw-on rather than a push-on friction connector would have been a great improvement.    
 
Far more of a concern is quality control.  Of late, I have had intermittent but continuing issues with the rotary band selector switch that controls AM/SW/FM/FM stereo bands.  Basically, the switch would fail to engage the proper band when rotated.  Taking apart the unit, which was aided by screwed-together construction of the cabinet and printed circuit boards, I found I had to remove a large PCB to expose all of the switch mechanism.  I then discovered that the rotary switch is not a direct-operating control; instead, it operates a plastic geared cam linkage that in turn pushes a low-end band slider switch which is offset an inch or so to one side, and mounted directly on a second PCB.  The slider switch is then moved one of four positions by the camming action of the linkage.  At best, this is a cost-saving design - it works, but only just.  With the slider switch now exposed, I managed to restore functioning with a shot of DeoxIT electronic cleaner/lubricant. 

This habit of using extended linkages to save money instead designing them from the outset to use direct-acting electromechanical rotary contact switches is being seen more and more on consumer-level electronic items, along with the usual touchpad membranes and microswitches.  For my part, I would have gladly paid $25 or $50 more for better switch design and quality, at least specifying materials commensurate with the quality of the rest of the radio.
 
Conclusion
UPDATE 02/03/11: The KA2100 finally succumbed to failure of its band selector switch that controls AM/SW/FM/FM stereo bands.  It is long out of warranty, and unfortunately replacement parts appear to be unavailable from the supplier.  Either the switch wasn't making contact anymore, or it was poorly soldered into the printed circuit board in the first place.  Whatever the precise cause,  the loss of band function has rendered the radio useless.  

When it works, the KA2100's reception capability is truly impressive, but I can't recommend it given the lack of quality control by Redsun on my example.  I don't know whether or not the C. Crane version would be better built, but I won't be purchasing any Redsun or Kaito products in future.