XHDATA D-808/Sihuadon D-808 AM/FM/SW/SSB/Airband Portable Radio
UPDATED May 2023:
The original XHDATA D-808 was released several years ago and rapidly became a favorite model for radio enthusiasts due to its excellent performance and a very complete set of features at a relatively low cost just over $100. There may have been ongoing changes along the way but I am aware of two main revisions, one which occurred in 2021/2022 and one more recently in 2023. There has been much discussion online about reduced AM performance of the new version so I decided to obtain one to compare with my original D-808 and the results were interesting
Above: Top – Original Display Bottom – New Display
The original (2018) version has a bluish/white backlight, a USB Micro port and several variable coils on the main PCB which is dated 2017-0829. The 2022 revisions retained the USB Micro port and adjustable coils with the same 2017-0829 date on the main PCB as on the original version but the audio amplification was changed and the display PCB was now dated 2022-1128. It still sounded the same but this version had some residual hiss which could be heard through the speaker or earphones with the volume control at zero. Not a big issue in most situations but definitely there and it could be bothersome to some people when listening very quietly, especially when using very efficient earbuds. There was also a change to an orange backlight, the addition of rubber feet and different On/Off button functionality. (On the original version a long or short press will turn the radio on or off, on the 2022 version it must be a short press).
The newest 2023 revision retains the 2022-1128 display PCB but deletes those coils on the large PCB in favor of fixed chip inductors according to XHDATA. I also noted the residual hiss is gone…this newest radio is dead silent at zero volume just as the original version was, and the USB jack has been updated to Type C. I also noticed that when the old and new radios are set to display Signal Level, when the radio is turned off the original model reverts to Temp while the new model reverts to AL (Alarm Time).
Above: Top – Original PCB Bottom – New PCB
So what remains is to test how the radios are different in terms of reception, and for this I went into my backyard which is very free of any RFI…I can hear distant signals which are so faint as to be unintelligible murmurs…right down into the band noise. In noisier environments the differences will be much less apparent. Tests were done at midday when signals are weakest and most stable.
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.
Above: Top – Original PCB Bottom – New PCB
Then I got the 2023 version which deletes the variable coils and replaces them with fixed chip inductors. The new model now has a USB C port but otherwise looks like the 2022 version. The loss of reserve volume on AM was slightly greater than on the 2022 version although on some signals at the top of the AM band the difference was slightly less. I could no longer describe it as subtle…it’s clearly quieter on faint signals. I must add however that I could hear everything on the new radio I could hear on the older one but at reduced volume although I suppose if a trace of weak carrier was just barely detectable on the original model it might not be there at all on the newest one but that would be a very faint trace of a carrier…not any kind of listenable signal. I should also say that for slightly stronger listenable signals there was always enough reserve volume to drive the radio into distortion, so it appears this reduction of reserve volume is of more importance to the faint signal DXer than to the program listener. Yes, the original model is preferable but the difference won’t affect you unless you like to chase down very weak signals.
Also interesting is the fact that on SW both the old and new versions had lots of reserve volume, so although the same volume difference was there on extremely faint signals, even the new model could be pushed to very loud volumes even as signals faded into the background noise…there is no volume problem on SW. Also, at times the 2023 model seemed just a hair better on SW with just a tad less background hiss on weak signals although many stations sounded the same…they are very close.
The Upshot: Well, there’s no doubt that the latest model is slightly less desirable for hard-core DXers who chase down very weak AM signals in very low noise locations although it is preferable to the interim model which had that residual hiss. I don’t think however that the difference will an issue to program listeners. On SW the newest model is equal and perhaps just slightly better than my original D-808. FM is unchanged and still excellent…I did not test LW.
What we can glean from all this? It is apparent that XHDATA has been evolving the D-808 over the past few years which seems to be very common today…many radio models undergo internal changes, some of which change performance in ways good or bad. Usually these are cost-saving measures or they may reflect changing parts availability. For whatever reasons, the D-808 has been modified at least twice since its introduction in 2018. It is interesting to note that the interim 2022 version which still had those adjustable coils had a slight volume reduction on AM but it also had that residual hiss, while the newest 2023 version gets rid of this hiss at the expense of another slight reduction in reserve gain. Yet on SW there is a ton of reserve volume which makes me wonder if an internal programming adjustment might be able to increase the gain on AM to match that on SW. If they can do that everyone will be happy, but for the type of listening I do the D-808 remains a great radio for the price and I still recommend it.
Below is the original D-808 Review which still pertains except for the differences noted above.
Although it has been available for a while now, the more I heard about this radio the more intrigued I became. It seemed to be a radio I should get to know, partly due to its provenance, partly due to several positive field reports of its overall performance especially on AM and partly due to its reasonable price. I paid $112.87 + $10 Shipping on eBay although it costs less in areas other than the US. My radio arrived 34 days after I bought it which was within the promised time range given in the auction. Why so long? That’s where the history of the XHDATA D-808 gets interesting and it has to do with a lack of patent protection among Chinese manufacturers.
Redsun, who worked with C. Crane in designing their one-of-a-kind CC Skywave and Skywave SSB models, has no control over other manufacturers who are seemingly free to copy parts of those designs, and to modify them any way they want to. This is also the reason that manufacturers no longer provide schematics and service manuals for their products which used to be standard practice which is a sad state of affairs.
Such is the origin of the D-808. Evidently, to head-off conflicts with C. Crane, Redsun agreed not to export the XHDATA D-808 to the US, but eventually an enterprising eBay seller found a way to ship the radio to the US via Israel. Thus, the higher price than we would otherwise have had to pay (although I think the D-808 is still a bargain) and the longer shipping time frame as well. Normally I would hesitate to pay a premium for a radio not normally sold here but in the case of the D-808, reports of its performance indicated that it may be worth it.
Although the XHDATA D-808 is styled differently than the Skywave and is a bit larger, it is based on the same Silicon labs Si4735 DSP Chip, which is used in many radios including the popular C. Crane Skywave SSB, Eton Satellit and Traveler III. And while the D-808 eliminates the NOAA Weather Band of the Skywave radios (since that is a US-service it would make no sense in a radio not intended for the US market), there were a few enhancements which elevate the D-808’s performance up a notch – RDS on FM along with better sound quality and slightly better AM sensitivity. The primary reason for the superior AM is the D-808’s 3 7/8” ferrite rod antenna versus the 2 ¾” ferrite in the Skywave radios…this larger ferrite rod easily accounts for the difference I hear.
Note: The very similar Digitech AR-1780 runs on AA cells rather than the XHDADA’s internal Li-ion cell and is available from Jaycar.com or in other areas Google “Jaycar” or “Digitech”.
Features and Specifications:
FM: 87.5–108 MHz/64-108 MHz With FM RDS Stereo/Mono Switchable .1/.01 MHz Tuning Steps
MW: 520-1710 KHz/520-1620 KHz 10K/9K/1K Steps
LW: 150 – 450 KHz 9K/1K Steps
SW: 1711 – 29999 KHz 5K/1K Steps
Air: 118-137 MHz .25/.001 MHz Steps
SSB With Fine Tuning Control (Fine Tuning works on all bands)
Tune via Knob or Up/Down Buttons with ATS
Direct Frequency Entry
MW/SW Bandwidths: 7) 6K, 4K, 3K, 2.5K, 2K, 1.8K and 1K
SSB Bandwidths: 6) 4K, 3K, 2.2K, 1.2K, 1K and 500 Hz
Switchable Display: Time (Default), Signal Strength/Signal To Noise ratio, Temp (Fahrenheit or Centigrade) and Alarm Time.
Illumination Can Be Automatic or locked on
Squelch Control (Works On all bands which is unusual)
Earphone Jack 3.5mm
Ext Antenna Jack 3.5mm for SW/FM/Air
Fast/Slow/Stop (Lock) Tuning Speeds
You can also defeat the Beep Tone by depressing the #5 Beep button with the radio off.
Light Button turns on the dial illumination permanently…a nice feature.
Power Source: USB rechargeable 18650 Li-ion 3.7v battery
Micro USB Cable and Carry Case Supplied
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.
The XHDATA D-808’s AM performance ranks *** in the AM Mega Shootout list which places it at the top for this size class of radio. On AM it outperforms well-known, larger radios like the Tecsun PL-660/680/880, Sony ICF-7600G/GR or even the much more deluxe Sangean ATS-909X using built in antennas, hearing faint signals which are nothing but hiss on those sets. (Update: The newer Sangean ATS-909X2 now also ranks *** on AM). The only medium to small size radios that match is AM sensitivity are the slightly larger Eton Satellit, the original Degen DE-1103 (not the later DSP version) and the discontinued Eton/Grundig E5/G5 twins. For its size it is one hot little AM radio.
FM Performance is also as good as it gets in the best of today’s DSP portables…it earns a solid ***** in the FM Mega Shootout list and offers selectable Stereo/Mono and RDS for FM which are welcome features. Contrary to what the manual says the antenna jack does work on FM although it does not disconnect the whip antenna. I simply collapsed the whip and tried it with a typical folded dipole and was able to improve several very weak stations. The Signal Metering was a decided help here with comparative numerical readouts of both signal strength and signal to noise ratio.
Shortwave too is excellent in this category. Comparing it with well-known models from Eton, Sangean, Sony and Tecsun it was very close over most of the SW spectrum compared with the hottest of current day SW portables. Again, this is not surprising as many of these radios use the same or similar DSP chips which seem to do wonders with the shorter whips you usually find on smaller radios. Occasionally the D-808 was just slightly less sensitive on very weak trace signals, but on other signals it ran with the best. One radio here, the PL-660 does have the benefit of synchronous detection which works well and sometimes is a huge benefit. Notably, with all of these smallish radios including the larger ones such as the PL-660 and ATS-909X , holding the radio in your hand sometimes provides a large boost due to the counterpoise effect and moving any of the radios a few inches here or there often caused bigger differences in reception than the inherent differences in the radios. Also, it’s important to remember that far bigger sensitivity differences can be obtained with a short wire antenna, such as the common reel-up types.
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.
I checked the antenna jack and found it was effective on SW, FM and Air bands. I had read some online comments that it worked on AM as well but mine does not. It’s possible this has been a running production change but it’s also possible one could plug in an external antenna and via inductive coupling or grounding get some increase in AM signals…I have observed this effect on many radios.
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.
I also found that the Squelch control actually works in ALL bands which is an unusual feature – the manual states that it only works in Air band which is usually the case.
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.
You can defeat the Beep Tone by depressing the #5 Beep button with the radio off.
Tuning is very flexible. You can use the Up/Down buttons which also offer Scanning and ATS functions, the Tuning Knob can be pressed in to toggle among Fast/Slow/Stop tuning speeds, and when left in Fast mode the Fine Tuning thumb wheel tunes in Slow Mode so you have instant access to two speed tuning without changing tuning modes. You can also directly enter a frequency which requires hitting the Freg key first. There are also 500 Memories set up in Pages for easy organization.
Sound quality is also very good for this size radio and in fact it falls right between the smaller Skywave/Skywave SSB and the larger radios such as the Eton, Sangean and Tecsuns we’ve mentioned. The XHDATA is too large to be considered an Ultralight, but for its slightly larger size you do get slightly better sound.
Also on the plus side the D-808 seems to have no soft muting which makes it user friendly and great for just tuning around. Some have complained about the muting or chuffing while tuning but what I found is that both of these are greatly reduced in Slow Tuning mode. In that mode the volume does drop a bit while you tune but not so much that you can’t hear what you’re tuning through, and it releases quickly. Yes it could be better but it’s not bad.
Battery Life with the supplied 18650 Li-ion 3.7v battery is stated at 34 hours at normal volume even with the dial illumination on some of the time and my radio easily met that figure giving days of use between charges. At first, I thought I might have a bad battery because after I fully charged it and started to use the radio the battery strength indication dropped by one segment very quickly, but I found that this is just the way the meter behaves. The radio played on for several days of general use while the meter dropped slowly.
Of course, there have to be some weaknesses as well but given the small size of the D-808 I didn’t find many. The biggest omission is that there is no Local/DX switch or control to limit strong signals from external antennas and indeed, in some of my external antenna tests there was some overload which the larger portables could handle better. On the other hand, the Skywave has no external antenna jack or Local/Distant Switch. These features are common on all of the larger radios which I think speaks to the reality that as radios get smaller they are more geared to portability rather than to permanent installations tethered to external antennas, so there are better choices if you will often use an external antenna.
Some Notes Concerning the XHDATA D-808 Owner’s Manual:
It’s not the best manual but it will get you through most of what you need to learn. I found a few errors but there may be more. Some of these seem to be caused by the fact that the same DSP chip is usually programmed a bit differently in other radios.
*Although called out in the manual there is no “Charge Button” on the radio. The D-808 is designed to be always in automatic charging mode since it contains a rechargeable Li-ion battery.
* Squelch works on all bands contrary what the manual says.
* External Antenna Jack also works on FM but does not disconnect the whip antenna.
* Under “Time Set” the words “Time Set Key” are missing from the procedure.
Conclusion: The XHDATA D-808 certainly reflects the state of Chinese manufacturing today in both good and bad ways.
The Good is that innovation never stops. Even within a given model there are often (maybe I should say there are Usually) design changes along the way, such that a radio bought today may be internally revised from that same model bought only months before. This can represent a step forward or backward depending on the reasons for the revisions. But without a doubt they are churning out new models constantly and the overall state-of-the-art is in some ways better today than just a few years ago. The XHDATA D-808 is a perfect case in point…it seems it would not exist if C. Crane and Redsun had not worked to design the Skywave radios. It also represents an excellent deployment of the Silicon labs Si4735 DSP Chip, with great basic DSP performance unhampered by soft muting or questionable noise reduction programming, and with a great feature set.
The Bad is that there is seemingly no longer any protection of intellectual property. If any design can be taken, copied (they call it “reverse engineering”) and modified, that certainly might stifle development because it’s cheaper to copy an existing circuit than to design your own. I think it would be frustrating to sweat out and spend money on a new design only to find someone else had taken your radio and used it as a starting point for a new model.
With all that said I don’t usually get into the politics of things…I just wanted to explain how this radio came about and in what ways it is like and unlike the C. Crane Skywave radios. But for me, in the end, it’s all about the final product and I rate the XHDATA D-808 as a top performer in its category. It’s just a little larger than an Ultralight but smaller than what we typically call a paperback book or travel sized radio, and it may just become my new travel radio of choice.
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