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The PL-660 has 2 (I think unspecified) ceramic IF filters for SW, which are doing a good job serving 90% of all typical purposes for such a radio. The D-808 on the other hand utlizes the DSP for IF filtering and offers whopping 11 different bandwidths (6 on AM and 6 for SSB), this is even more than the PL-880! This sold the D-808 to me the most, for example I like to improve my very poor CW listening skills every so often, and always having an even narrower filter up the sleeve can save otherwise hopeless DX reception in the ham and broadcast bands. But are they any good? Sangean made some basic decisions with the 909×2. Many of them are quite positive over the old 909x. For many users the 909×2 has more than enough features to justify the higher price of the receiver. Every company that’s still manufacturing receivers makes its own decisions. It’s as important that we voice our gratitude to Sangean for its latest (possibly last) effort to revise the 909xxxx series as it is to Tecsun for offering no fewer than THREE superb world band receivers. The Si4735 DSP chip has markings of “3560, DCUL, .738” and provides a wide range of AM bandwidth choices for the Medium Wave DXer (6K, 4K, 3K, 2.5K, 2K, 1.8K and 1K). These perform very well, and as with the other DSP-enhanced portables, the narrowest bandwidth (1K) provides the most sensitive AM band reception. Last week, I posted a few photos of the new XHDATA D-808 and Digitech AR-1780–two of the hottest portable shortwave radios to hit the market in recent months.
The manual claims that the D-808 can’t be charged when it’s on but I found that’s not quite true–it sure takes much more time but I could top off a slightly discharged battery just fine. Only below 3 MHz it’s not all that great on the whip, and that’s where the D-808 beats it – listening to top band (160m) hams works surprisingly well for a 25 inch whip. Between 3 and 30MHz the D-808’s sensitivity appears to be almost on par with the PL-660, the PL-660 often wins in terms of intelligibility at the “minimum discernible signal” (MDS) threshold. For example, on a day with bad conditions Gander Radio on 6604kHz USB had a barely audible signal on both radios. But I could occasionally decipher some words on the Tecsun that didn’t make it through the noise on the D-808. These photo finish victories for the PL-660 can be observed across most bands, but it needs ridiculously weak signals to spot the difference. The XHDATA D-808 bandwidth filters seem to have excellent characteristics – AM/SW selectivity seems very good while maintaining good high frequency response at all but the very narrowest settings which allow great selectivity and sensitivity for signals at the threshold of audibility. FM selectivity is excellent and on par with the best of today’s DSP FM portables. Here are some of the key points I gleamed from a digital copy of the owner’s manual: Radiwow R108 Features:
Display/Backlight
Solution 1: Use a battery operated headphone amp. Keeping the volume on radio to moderate/high use the volume on headphone amp to reach desired level. This will completely eliminate the noise. This works because the audio signal to noise ratio increases so much with moderate volume that when you reduce the audio through the amp the noise levels become absolutely inaudible. I use FiiO Q1 amp which has a digitally stepping volume control which eliminates any stereo channel imbalance at low volume. This imbalance issue is also there in d808 because it has analog potentiometer vol. control.
Refer to the photo below. Using the previous procedure to install shrink tubing (which is described in the PL-380 transplant article) install a 2.5” (63mm) length of shrink tubing over the two Litz wire ends, and shift the shrink tubing into the position shown in the photo. After this is done cut the two Litz wire leads to the lengths shown in the photo (NOTE: make sure that the ends of both Litz wires are cleanly cut, not frayed and at the minimum diameter before attempting to insert them into the shrink tubing. The process is much easier when the Litz wires pass smoothly through the shrink tubing). I found the antenna quite stiff to extend. Lubrication did not help. In earlier versions of the radio, this contributed to antenna failure. All these radios can overload easily at night with external antenna and so the local/DX button helps a lot, unfortunately the D-808 overload with external antenna can be quite a lot with no form of attenuation. Radio Waves: SWL Contest, Shortwave Modernization Concerns, Still Need AM, and ARRL Asks for Comments on 60M Rulemaking I have the XHdata D-808 and find it a good radio for the money, I have no issues with battery life and have left it for weeks without use and still plenty of battery life.I also have a Grundig Satellit 750, if I hook that up to the external antenna that came with the Sihuadon D-808, it blasts in with a signal of 20-25. Placing the D-808 on the induction antenna resulted in a very pleasing result, which was it did get reception of Iceland on 207 kHz. So this shows that it is possible to DX on the LW bands with the D-808 with some “external help”. The 808 was and still is compared to the CCrane Skywave SSB, a much smaller and compact receiver. Unfortunately, in my experience both suffer from soft muting. If you connect the receiver to a large external antenna, you will encounter many IMD signals. As there is no built-in attenuator, you will need an external one.
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