The Realist: Ultra Portable Radios

Today I have another guest post from the Realist, this one on small portable radios:

Audiomax SR-202 in blue and silver, Sony SRF-S84 in blue and silver, Memorex MR4210,
Tecsun R-103 in black and silver, and a red BIC lighter.

Ultra Portable Radios

Disclaimer: All products mentioned in this review were purchased by myself. I did not receive samples, evaluation models, or other compensation from manufacturers or retailers. I have no formal relationship with any manufacturer or retailer mentioned in this review - I have only been an arms-length customer. Further, this review reflects my unique circumstances and subjective opinions with regard to performance and other characteristics of the products being reviewed. Your mileage may vary.

For a while, I've been looking at portable radios that could be stored in an emergency or EDC (Every Day Carry) kit. There are a wide variety of smallish radios available, all of which reflect different design compromises. During this long search for radios, many have disappeared from the domestic market as most people have moved from listening to radio to listening to a digital audio player, or listening to streaming audio or music on their cell phone or computer.

One class of radio suitable to EDC are what I'll dub "ultra portable" radios. These are tiny radios powered by a single AAA cell. They are regularly described as being the same size as a cigarette lighter. They range in price from less than ten dollars to nearly forty dollars, and most can only be purchased online.

Currently, I have found four models to be readily available new. The Audiomax SR-202, the Memorex MR4210, the Sony SRF-S84, and the Tecsun R-103. The Audiomax and Sony radios are most readily available in silver, with blue being more difficult to find.

All four radios are AM/FM radios. Although, the Audiomax SR-202 is monaural FM, while the others are stereo FM. All radios use common stereo ear buds. None of these radios have built-in speakers, so ear buds are mandatory. All radios are completely analog.

For all four radios, their performance is compromised by the diminutive size of the internal ferrite bar antenna, which is typically one inch in length. For all four radios, the bar antenna is horizontal, located in the bottom of the radio. By comparison, most other portable radios have a bar antenna that is typically 2 to 3 inches long. All four radios use the headphone/ear-bud leads as their FM antenna.

Testing and Evaluation

For testing, I primarily relied on high efficiency Sony MDR-E9LP ear buds ($10), with the volume set to a moderate level for listening in a normal office environment. The ear buds supplied with the radios were universally less efficient (i.e. a higher volume setting is required, with increased current consumption) than the Sony ear buds.

While I live and work in a major metropolitan area with numerous radio stations with strong signals, I work in an office environment that makes AM radio reception challenging. Some of my testing was done at my office, and some was done at home. Further, I sometimes used external inductively coupled antennas (a ferrite loopstick antenna and a Select-A-Tenna) in my performance evaluation.

FM testing was limited to verifying that the FM reception worked and had acceptable audio quality.

My evaluation of these radios was primarily limited to their ability to pick up local stations since I was evaluating these radios for inclusion in an emergency kit of some sort.

Audiomax SR-202

The Audiomax SR-202 is the lowest cost model reviewed. Of the four models, it has the stiffest tuning (making it the most difficult to tune). This radio also has some minor fit and finish annoyances that are easily corrected. One of SR-202 radios I purchased had a wire from the antenna sticking out the bottom - careful disassembly and reassembly solved that problem. Performance wise, this radio is incredible. It is very sensitive, with AM sensitivity that was indistinguishable from the Sony SRF-S84. As an added bonus, I was able to operate it for 560 hours listening to AM on a single Rayovac AAA alkaline cell. AM current consumption was 2.9 mA, and FM current consumption was 4.8 mA.

The Audiomax SR-202 is available on ebay through a US seller for $8, including shipping. (Search for "Mini Portable 2 Band Pocket Radio" from seller kuentl. In my experience, shipping from the Far East for this radio was problematic.)

Memorex MR4210

The Memorex MR4210 sells for less than $10 at Walmart, making it the easiest of the four radios to obtain. (It can also be purchased on Amazon or ebay.) It performed well with good AM sensitivity. It is slightly larger than the others, but not unreasonably so. AM current consumption was 9.2 mA, and FM current consumption was 12.5 mA.

Sony SRF-S84

The Sony SRF-S84 is basically a shrunken SRF-59, a radio renowned for its AM sensitivity. It uses the same Sony CXA1129 receiver chip found in the SRF-59. The SRF-S84 does have additional "Base Boost" circuitry not found in the SRF-59 for listening to music. It is the easiest radio of the group to tune. Unfortunately, it has the highest power consumption. AM current consumption was 17 mA, and FM current consumption was 21 mA.

At the time of this writing, the silver (sometimes described as "gold") Sony SRF-S84 is available on Amazon for a little over $33, but the blue version sells for nearly $85. Ebay prices from Hong Kong and China are around $35 for either color.

Tecsun R-103

The Tecsun R-103 was a bit of disappointment. Ergonomically, the radio is well designed, but it has problems picking up weak signals. When trying to tune a weak signal, lots of internal chirping and whining was heard. AM current consumption was 8.0 mA and FM current consumption was 11 mA. This radio is readily available on ebay for less than $20.

Summary

AM reception wise, the Sony SRF-S84 and Audiomax SR-202 seemed to have nearly identical AM performance. The Memorex MR4210 is almost as good, while the Tecsun R-103 performed poorly with weak AM signals.

For power consumption, the Audiomax SR-202 astonished me with an observed operation of 560 hours from a single alkaline AAA cell. I would expect the Memorex and Tecsun radios to operate for a couple hundred hours of AM listening from a single AAA cell. The Sony radio will probably provide close to 100 hours of AM listening on a single alkaline AAA cell.

These radios are all small enough that they can be stored with a set of ear buds in an Altoids tin. The Altoids tin would protect the radio and keep the radio and ear buds together in an emergency kit.

I would rank these radios from best to worst as follows: 1. Audiomax SR-202 because of its sensitivity and astonishing power efficiency. 2. Memorex MR4210 because of its reasonable performance and easy availability. 3. Sony SRF-S84, gets dinged because of its high power consumption - but for its power consumption, the Sony would be the hands-down winner. 4. Tecsun R-103, is last because of its poor performance with weak signals.