19 June 2006

redsun rf-1210 first look

I received my Redsun RF-1210 radio two weeks after sending the payment to Liypn, who is in China. The product's box was inside a bubble-lined envelope. The box contained the radio, a power adapter, and a reel antenna with a very thin insulated wire.

The labels on the radio are all in English. This receiver has a very similar appearance to Tecsun's R-9700DX (which I do not own). It is very close in size to my Eton E5. The RF-1210 lacks a backlight, so keep a light handy if you want to use this one in the dark.

The radio's plastic casing has an uneven appearance at the seam. Squeezing the plastic beside the seam on the top of the radio causes flexing. I don't know anything about plastic molding, but it appears that Redsun has some work to do to produce plastic components that are more exacting in dimension and form. On the other hand, the flip stand and the battery cover are solid and sturdy, and the plastic grill over the speaker barely bends under pressure.

Right after taking the radio out of the box, I extended the whip antenna to its full length of approximately 32 inches. Unfortunately, the two thinnest segments of the telescoping antenna are noticeably bent. If anyone has a suggestion for correcting this safely, I'd love to try it!

I plugged the radio in with the included 110-volt adapter to get started, as I didn't have four AA batteries handy. I am glad that a switch is used to power off the radio rather than the volume dial, but "off" is unfortunately one of the positions on the news/music tone switch.

Here are my impressions after tuning around the dial for a while and listening to a few FM, AM (mediumwave), and shortwave broadcasts.

There is only a very small width of the tuning needle visible between the FM and mediumwave frequencies. Making the needle more visible here would be a nice improvement. The higher ends of both the FM and mediumwave bands are quite compressed, so fine-tuning is required to hit the desired frequencies.

The 76-108 mhz range supports both the Japanese and non-Japanese FM bands. I found that some FM broadcasts were noisy. Even though I could find the strongest point for a local station on the FM band, a fair amount of static was present. There were two spots in the FM band where I could hear two broadcasts at once, so selectivity seems poor. I haven't experienced this in the FM band before, so I'd be interested to hear if someone else is able to explain the problem.

The 525-1610 khz range for mediumwave leaves out the extended AM band in North America. Why does this radio have full support for the FM band but not the mediumwave band? Anyway, mediumwave reception seems better, as receptions of strong local AM stations were consistently clear. I couldn't find a signal weak enough to test the directional quality of the mediumwave antenna, and I don't yet know what's inside this radio. (On that note, I am still awaiting an email with the English manual from Liypn.) This acts like a radio that's only good at receiving strong local mediumwave signals.

Shortwave receptions are clear, similar to the experience on mediumwave. It is here though that frequency drift causes the most problems. I have only done a few shortwave receptions with this receiver: Radio Canada Intl on 17765 khz, KBS South Korea on 9560 khz, Radio Havana Cuba on 9550 khz and 6000 khz, and WWV as mentioned below. The KBS reception was notable for becoming noisy after a few minutes and requiring retuning.

This radio has a couple tuning problems. First, the needle that sweeps the tuning spectrum can touch the surface of the tuning display on the right side, making a clicking sound. This happens when reaching certain locations of the tuning spectrum or when jiggling the radio. I don't experience this with other analog-tuned radios I own, such as the Tecsun R-912 and Tecsun R-9012.

Second, the visual location on the tuning spectrum where a station can be found will change depending on which direction the tuning is going. I'll try to explain this more clearly with an analogy. Imagine a tuning scale that is marked with numbers from 1 to 10. Now imagine that you are tuning, starting from position 1. A station you want to hear can be found from position 5 to position 7. You tune all the way to 10, and then tune in the other direction. Now, the same station is found from position 5 to position 3. So, the tuning needle is not an accurate representation of the tuner. It also makes usage difficult as I often tune all the way past a station to evaulate the signal strength, then tune back into it. That type of usage is difficult with this radio. It makes retuning after frequency drift more challenging as well.

Further evidence of the tuning needle's inaccuracy is seen when locating WWV at 5 mhz, 10 mhz, and 15 mhz. Each of these three frequencies is directly labeled on the tuning scale. WWV at 5 mhz is found with the needle fully below the 5 mhz label. WWV at 10 mhz is found with the needle fully above the 10 mhz label. When finding WWV on 15 mhz, the tuning problem described above is experienced. If tuning in a downward direction, the station is centered on the 15 mhz label. But if tuning upward, the station is above the 15 mhz label.

I like the RF gain knob on this radio. Unlike on my Tecsun BCL-2000, the RF-1210's RF gain seems to provide a linear response. Decreasing the RF gain was useful for reducing noise on an unidentified reception near 15550 khz.

The problem for Redsun here is that their RF-1210 is similar to the Tecsun R-9700DX in terms of price (on eBay), features, and appearance. That brings into focus the questions of quality and performance, where I feel that Tecsun would win. This Redsun radio is below average in terms of construction, tuning accuracy, and signal clarity. Without having used it, I would still suggest that the R-9700DX is a better value due to the quality of the Tecsun radios I have used, and the fact that the R-9700DX is a second revision product.

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