Joined in 2023 
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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. It is interesting to note that although many radios use the same Silicon labs Si4735 series DSP Chips, these chips offer many features which may not all be available in any one radio, as well as many settings the manufacturer can adjust to customize many details of operation. Add to this the fact that every radio will have its own ferrite rod AM antenna, SW/FM/Air whip antenna and speaker which will affect reception and sound quality and you can see that two radios can use the same DSP chip and yet be quite different in many ways. There are also, of course, many areas where performance will be identical…my own experience suggests that SW/FM/Air reception tends to be similar when the whip antennas are similar while AM reception will be different depending on the size of the built-in ferrite rod AM antenna. It does use the thin Li-ion rechargeable battery. Like you, I’m not a big fan. I see advantages in terms of weight and recharge-ability, but I much prefer AA batteries. So particularly on LSB, the offset on my D-808 varies quite a bit over the entire coverage range but I think this is within the allowable tolerance for such a radio. The PL-660 has slightly better results but it also has a center-indented fine-tuning knob making small corrections quite difficult. In AM mode they are both spot on. The XHDATA D-808 has a nice display which can show Time & Frequency together which is very convenient, along with additional options of Signal Strength/Signal to Noise Ratio, Temp (Fahrenheit or Centigrade), Alarm Set Time and Time which the radio defaults to when turned on. The signal readings are relative and can’t be directly related to typical S-Meter readings but nevertheless they provide interesting info about what you’re tuned to and can be a definite advantage while tuning or antenna aiming. Display Illumination is automatic or the Light Button will turn it on permanently if desired…another nice feature.
The gold/brassy coloured coils coils are (almost certainly) the FM tuning/osc coils. They’re not wound on a former so they’re easily de-tuned if they’re bumped, and the spacing / layout typically needs to be hand-adjusted at bit for final alignment anyway.
Realistic Expectations
Additional years ago, I used receivers such as SONY SW-55s and Panasonic RF-B65s in ocean side DXing. These are fine receivers, but the 55 is limited to two bandwidths, NARROW and WIDE – similar to the SONY 2010 and SW-77, both of which also had effective synchronous detection. I’ve read a similar comment in one of the other posts about the D-808, so it’s possible that a few units come with this issue. Are you using the proper unprotected 18650s with pin? Another thing to rule out as a potential culprit would be the charger, but I guess the 808 shouldn’t indicate a fully charged battery then. I hope you have no trouble getting the 808 replaced! The XHDATA D-808 has multiple display functions, which can be toggled by the indicated key. The first option is the temperature in either Centigrade or Fahrenheit (depending on your pre-set preference), while the second option is the alarm time. The third option is the current time (which you need to set according whether you prefer UTC or local time), while the fourth option is the received signal strength in both dBu and dB. My first comparisons were between the original (2018) D-808 and the 2022 version and the biggest difference was on AM where there was a very slight reduction of reserve volume on extremely faint signals. To explain, on any listenable station there was enough volume to drive the radio to distortion, but on faint traces of signals the new model wasn’t quite as loud as the original. Interestingly, if I matched their volume levels by slightly reducing the volume of the original D-808, the actual reception…the signal to noise ratio was the same, it just couldn’t play quite as loudly. However, this was fairly subtle. Also, the original radio had a spurious whine on an extremely faint signal on 740 KHz…there was no whine on the 2022 sample. This was the only frequency where I noticed this spurious whine.
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. NOTE: The Litz wire connection points on the circuit board are surrounded by other important components. It is important to avoid solder drips on these components, or solder bridges to their leads. Solder the Litz wire leads down at an angle to avoid these surrounding components, and use the minimum amount of heat and solder to ensure good electrical connections) 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”. I always try new receivers at my favourite listening post at the (German) North Sea shore, many of you know how beneficial such a location is for DXing. My favorite spot there is far away from any houses, power lines or other interference sources on the land side, so besides some sheep-made noise the man-made noise is as low as it gets, measured less than -130dBm (which is the receiver noise) on a 1/2 lambda dipole above 10 MHz. Outsides where the noises of the digital world are gone, the D-808 presents all bands almost as filled as my dipole at home and so there’s always an interesting QSO or some overseas radio program to enjoy. To give you an idea on what I mean by “no compromises”: my companion on today’s walk was NY2PO from upstate NY (3,728mi/6,000km away) on 40m, constantly coming in with a signal allowing for convenient listening, despite the bad conditions (SFI=68 A=10).LW is poor, better than the PL-660 but still poor, Good on MW and Very good on SW. I hate the soft muting. It is a noisier radio than the PL-660 which is less fatiguing. But due to the differences in the audio/speaker sometimes the D-808 can be more intelligible on weak signals than the PL-880 or PL-660 and even the S8800.
I do wonder if Tecsun have improved the PL-660 over the years. More than likely as most manufacturers make undocumented improvements over the years. The build quality is also very impressive, the buttons are as rattle free as they are on the D-808. 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. SSB performance was good by portable standards. It was fairly easy to get natural voice quality and the continuous fine-tuning control with its numerical +/- readout is a joy. The Fine-Tuning knob works on all bands by the way.Here are some of the key points I gleamed from a digital copy of the owner’s manual: Radiwow R108 Features: It is confusing that the document number of the schematic contains “Eton G3”. But as Etón G3 was a traditional double conversion receiver without DSP, it cannot be the receiver shown in the schematic.
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