A DW01A (IC2) & a 82015A MOSFET (IC1) do overcharge protection, while a TP4056 (U2) charges the Li-Ion battery at 400mA until it reaches 4.2V. Initially I thought that this behavior wasrelated to a defective component,but now that I have my unit (new version 2021), I am not so sure.As the volume is a pure analog potentiometer, the noise must be generated inside the CS4863 (LM4863 equivalent) audio power amplifier IC. So the manufacturer have cut production costs by eliminating costly LC trimmers and active components of the Pre-Scaler and DC-DC converter, reduced the alignment requirements at the assembly line, and potentially have reduced some internal noise coming from the MCU/Display into the DSP, at the cost of offering a radio with lesser ability to reject strong spurius RF signals.

LW band seems to show poor sensitivity on DSP radios like this model category, due to a poor design of the RF analog passive components that favors the MW band.Doingmanual tuning across RF bands results in muting/chuffing sounds when changing eachRF step.This seems to be a design characteristicof DSP based radios. In this model the volume drop can be reduced by seleccting the Slow tuning mode.

Despite being mentioned in the Operations Guide, there is no key for that. The D-808 was designed with automatic charging and management of the installed battery. Some have reported that the squelch is not fast enough to unmute resulting in loss of the initial conversation. I can confirm this to be true, but it loses just a small fraction of a second, not really an issue.

My 2021 unit came with 3.81V in the battery (still a XHDATA 2000mAh device) and the battery level indicator had 2 bars. Some owners have reported a fast battery depletion even when the radio is powered off, but this seems to be a fault developed with usage or a manufacturing defect. Looking to the publicly available pictures, extensive changes were made in the circuit diagram and PCB layout of the Receiver board. Due to product quality problems within 3-12 months of receiving the product,we can repair it for free, but the customer pays for the logistics costs incurred. SIHUADON R-108 not only has a manual search mode. It also has an Auto-Tuning Memory (ATS) mode. Press and hold “BAND” to automatically search for stations with stronger signals and store them in the radio. This mode greatly saves the time spent manually storing the station. For stations that do not receive strong signals, it is suitable for manual storage. Dual mode storage station for you to choose from.

My 2021 unit present these transitory noises. I wonder if the muting system is not being enabled by the MCU firmware. Bug or hardwaredesign fault? Allegedly, the Auto Tuning and Store feature seems to only find the stronger RF signals, probably because the firmware was set to use a too high threshold detection level, and there is no user setup to change it.The same behavior happens for the Manual Scanfeature, by presssing and holding the Up or Down keys for 2 seconds. Telescopic antenna - Last section (with tip) detached from the rest. Also, the antenna mounting seems to be fragile, requiring great care when rotating it, as it can break the plastic support.Confirmed empirically, by listening to some radio stations at night. This radio is kind of silent below 2.5MHz. Confirmed. Litz wire speccification used in the single coil around the magnetic ferrite rodantenna is optimized for MW frequency spectrum. An additional LW coil with adequate Litz wire would be required, as seen in the good old radios of yesterday.

The design choice used on the D-808 was to save costs on the audio pre-amp and simply configured theCS4863's OpAmp1A andOpAmp2A with a very high bridged mode differential gain of 77 (!)Even when inserting a fully charged Li-Ion battery, the radio only shows 3 bars (corresponding to at least 4.1 Volt reading)for a few minutes of usage.After that it will show 2 bars (around 3.7 Volt reading) for many hours of usage.Eventually it will show just 1 bar (low 3.4 Volt reading). The battery was charged using the radio integrated battery management and supplied microUSB cable conected to a 5V/2A smartphone poweradapter.