Michael,

I think that those links were posted in more than one message.

The Radiwow R-108 disassembly links are posted below  

RF Circuit Board  https://dreamcrafts.box.com/s/456oocxphu0uytkz8i9trfdhb06750i3

Cabinet Disassembly (Digital and RF Circuit Boards)  https://dreamcrafts.box.com/s/xxhqja4031uo16j1rma41xk0t84ujm0p

Lithium-ion Rechargeable Battery  https://dreamcrafts.box.com/s/zn97mtiathscw54qn5i8tdfs4jesem8d

CC Skywave SSB and R-108... the identical sized Shenzhen "siblings"  https://dreamcrafts.box.com/s/jvenlc0mg6a8lqktld6ouyna3fjzbhaw

The R-108 7.5" loopstick transplant links are posted below

Finished model with stock and enhanced loopsticks  https://dreamcrafts.box.com/s/o115x36ipt8itob81yofwpv8yaamcrou

Finished model-- Mug Shot   https://dreamcrafts.box.com/s/20zk1eyp3el94o8znvlbolk6cp4quyrq

RF Circuit Board soldering procedure  https://dreamcrafts.box.com/s/ap4cv77p9kvc8l86xzg3deymnktf8yc5

Litz Wire Routing System  https://dreamcrafts.box.com/s/y23snut7dokolluq5rvx9kkbv4f7jc2e

73, Gary

Thanks Remy,

<<<   I have never used or even seen a C.Crane radio but still, if the D-808 is a copy of the C.Crane and judging from it, “technical innovations” doesn't seem to mean improvement. I find the D-808 rather poor on SSB, especially when used in ECSSB mode, compared to its performance in AM, and compared to other receivers, like the SONYs for instance or the Tecsun PL-660.   >>>

Of course in comparison to the SSB circuitry in communication receivers (or even in the Sony ICF-2010/ 2001D or Tecsun PL-880), the SSB function of both the CC Skywave and the D-808 is pretty rudimentary. The challenge for C.Crane was to develop some type of SSB capability that would fit inside the very compact Skywave cabinet space (122mm x 75mm x 27mm), in addition to the RF and Digital circuit boards , speaker and other components. The C.Crane company was obviously quite proud of its achievement in developing the Skywave SSB model (shown in the photo below, next to the D-808), and started marketing the ultra-compact SSB-enhanced portable for $169.98 in the summer of last year. The sky-high price was probably an attempt to cover their research and development costs, but it was a very bad idea for a radio assembled in China, with a copy cat company in the same city eager to "appropriate" the technology.

73, Gary

                                                  

Hi Chris,

Le 12/03/2019 22:36, Chris Black a écrit :

Regarding SSB, when I first clicked the button, it showed LSB.
Not sure how I did it but now it only shows USB?

In the earlier days of the internet, one would have answered "RTFM"... ;)

You did it by pressing the appropriate button, the "Info" button.

This information is even printed on the set itself, in small dark red characters on a brown background. You need a good looking-glass to read it.

Well, the logic in that receiver is a bit strange, to say the least. To change from one sideband to the other you don't press the "SSB" button but the "Info" button.

When you get to +99 you get a pronounced HET.
Continuing to move the wheel up begins to decrement
the numbers with the typical BFO/zero beat sound until
you gat back to the starting point.
Any enlightening on how this thing thinks is most appreciated.

Strictly speaking it doesn't "decrement" the numbers, it jumps back to -99 and continues to increment them till it reaches +99 again.

Conversely, if you turn the wheel downwards, it decrements from +99 to -99, then starts again at +99.

Strangely enough in AM mode it tunes in 1 kHz steps and never jumps back. Therefore I always leave the main tuning knob in fast mode and use the thumbwheel for the slow mode.

All in all the D-808 is a rather good receiver, but it takes some getting used to.

To key-in 6070 kHz for instance, you have two options. Either "Freq-6-0-7-0-Freq", or "Freq-0-6-0-7-0". But on the MW band you don't have to key in the leading 0 or press "Freq" twice. Very strange...

Regards,

Rémy.

Gary, I must have inadvertently deleted
a key file... I can't find a comparison
between the
*R-108
*Supercharged D-108
*xdata 808

Could you repost links, please!
Michael UK

Hi Max,

<<<   Is the section of the ferrite rod rectangular mm 8x4 or round Radius 8 with to flatten sides?   >>>

The R-108 loopstick's ferrite rod is completely rectangular, with the flat (8mm wide side) facing up. A detailed photo of the loopstick installed in the R-108's RF board is attached with this message.

<<<    I have found this https://www.aliexpress.com/item/Tangda-soft-ferrite-rectangle-plate-core-ni-zn-material-4-8-50mm-magnetic-bar-4-8/32844810654.html

Disregarding the fact that the material could be different, will it work adding one bar at each end of the stock ferrite? They can be hold in position inserting everything inside a 8mm pvc tube and leaving out just the coil.   >>>

As you can see in the photo below, there is no space inside the R-108 cabinet to add anything to the loopstick. A small circuit board with the external antenna plug-in jack is to the left of the loopstick, and the tuning control encoder (on the digital board) takes up the space to the right of the loopstick. External loopstick mounting would provide more space, but in my opinion if you are going to go through the hassle of external loopstick mounting you should probably go all the way and perform a "Supercharging" operation with a much larger ferrite rod, 250/46 Litz wire and a matched-size loopstick frame. The 'Supercharged" D-108 works like a dream-- it's lightweight, compact, and has no digital defects like the PL-380 and other Tecsun Ultralight models.

73, Gary DeBock (in Puyallup, WA, USA)

                                                  

   

This is Chris, new to the group. I like my D-808, especially after Gary souped it up!

<<<   What do you mean exactly? What "technical innovations"?
I find the D-808 a very good receiver, but I don't know of any technical innovations.
73, Rémy.   >>>

Remy, I'm not sure that you understood the original post. There are no technical innovations in the D-808 model.

These were all in the development of C.Crane's Skywave SSB model, for which the Fortuna, California company undoubtedly used a lot of research and development money to design and build a decent SSB reception system that would fit inside a very compact, Ultralight-sized cabinet. The Chinese company simply copied the innovative SSB design in their D-808 model.

Gary DeBock (in Puyallup, WA, USA)

Thanks for the details Gary. Is the section of the ferrite rod rectangular mm 8x4 or round Radius 8 with to flatten sides?

I have found this https://www.aliexpress.com/item/Tangda-soft-ferrite-rectangle-plate-core-ni-zn-material-4-8-50mm-magnetic-bar-4-8/32844810654.html
Disregarding the fact that the material could be different, will it work adding one bar at each end of the stock ferrite?

They can be hold in position inserting everything inside a 8mm pvc tube and leaving out just the coil.

Le 12/03/2019 10:43, Gary DeBock via Groups.Io a écrit :

C.Crane Skywave SSB's technical innovations (in the D-808)

What do you mean exactly? What "technical innovations"?

I find the D-808 a very good receiver, but I don't know of any technical innovations.

73, Rémy.

For those who weren't aware of the fact, XHDATA and Radiwow are actually the same Chinese company, which has specialized in wholesale design appropriation of the C.Crane Skywave SSB's technical innovations (in the D-808) and physical cabinet characteristics (in the R-108). As for why they choose to go by two different names, maybe they figure that C.Crane would be less inclined to sue two companies for design theft than one? Of course C.Crane can't sue anybody in China, where the term "copyright" means "the right to copy." The Fortuna, CA company has reason to deeply regret building their breakthrough Skywave SSB model at the Redsun factories in Shenzhen-- which is of course the home of XHDATA/ Radiwow.

Anyway, since both reverse-engineered models have been "Supercharged" here with 7.5" loopsticks, I thought some members might like to know about their stock loopsticks. In the XHDATA D-808 model the loopstick has a 98mm x 8mm x 4mm ferrite rod with a 12mm coil, for a total inductance of 341 uH (see photo below).  The Radiwow R-108 has a 70mm x 8mm x 4mm ferrite rod with the same 12mm coil, for a total inductance of 212 uH. Of course because of the longer loopstick the D-808 has significantly better MW sensitivity than the R-108, and in fact has better MW sensitivity than any Ultralight radio (the D-108 is a little too large to qualify as an Ultralight portable).

Following the typical practice of companies in the Chinese domestic market, XHDATA/ Radiwow does not offer any manufacturer's warranty on their radio models-- but this doesn't seem to have deterred their sales on the international market. When a purchaser can get a $75 model like the D-808 which is highly competitive with the $169.98 Skywave SSB (with a few added features like a more powerful audio amp and a long endurance rechargeable battery), sales are definitely going to happen. So far the component quality of both the D-808 and R-108 seem quite good, and international purchasers are cautiously optimistic that this will continue. Hopefully this Chinese company will avoid the Tecsun example of cutting down quality (as in the PL-380's digital shielding) in order to increase profits.

73, Gary DeBock (in Puyallup, WA, USA)
                                              
                                                     

Thanks Paul. I'll see what I can ID on 1260.

In all your experiments, have you found any way the narrow pick up patterns for choosing multiple stations per MW freq? -FARMERIK

Thanks, Gary, for confirming that the PL-380 design has changed in a way that now makes it less suitable for supercharging. Something I suspected.  Fortunately, the PL-380 is still a nice FM machine!   I have a CC Skywave original model, which I like very much as is, so I'll probably keep it stock.

Hi Gary, thanks for the reply. I was just curious to know what is the advantage on having an higher inductance because i suspected that 430 uH was closed to the high limit.

Also, it would be interesting to have the specifications of length, diameter and geometry of the original ferrite bars on these radios to see if it can be just slided out and replaced with a longer one for those that do not want to get involved in winding a new coil. I wouldn't mind drilling a small hole on the top of the radio to follow a short path instead of entering with the wires from an exisiting hole.

I'm not sure who you are asking, Max, but the inductance of the PL-380 stock loopstick is about 280 uH, and the "Supercharged" loopstick version is about 350 uH. The internal Si4734 DSP chip is designed to accept any antenna inductance from 180-450 uH.

Gary

Hi, what is the inductance of the stock antenna and why making it different ?

Gary,

Since the original PL-380's were introduced in 2009 the Tecsun company has attempted to increase profits by significantly reducing the DSP chip shielding in all post 2011-models, resulting in the digital whine issue when the display is grasped. Knowing the Tecsun company as I do (I have performed about 25 "Supercharging" transplants on their models), I wouldn't be at all surprised if they reduce component quality even further in an attempt to increase profits. Because of this issue, I have personally stopped doing loopstick transplants on all recent-model Tecsun PL-380's. The only PL-380 models that I will "Supercharge" are the ones that I can confirm were manufactured between 2009 and 2011, with the fully grounded shield surrounding the Si4734 DSP chip. Of course, Tecsun's decision to reduce quality in order to increase profits is personally disappointing to me, especially after the time and effort that I spent to write out the 22-page "Supercharging the Tecsun PL-380" article.

As for your current project, I'm sorry that there are no quick solutions for the digital noise issue. Many recent Ultralight radio models have good internal shielding and no digital whine, such as the CC Skywave models (both the basic and SSB versions), the new Radiwow R-108 and the non-Ultralight XHDATA D-808. Of these four portables the Skywave models would be somewhat of a nightmare for beginners to "Supercharge," but the R-108 is reasonable, and the XHDATA D-808 is fairly easy (with the full procedure posted in another major article at  http://www.mediafire.com/file/t2989hg61vbkb5h/Supercharging_the_XHDATA_D_-808-FinalMWLW.doc/file

73, Gary DeBock (in Puyallup, WA, USA)

 

Does anyone have this radio as a ULDXer? Only 6 transistors, but has a long antenna based that the radio is used long side left to right, instead of up to down. I love the look of the radio. They are usually found cheap on ebay, and in good condition. Does it have a 3-gang tuner?

Having some trouble 'supercharging' my Tecsun PL-380.  Opened it up, disconnected its internal ferrite antenna and connected a new one I wound on an 8-inch R40C1 ferrite rod from Ming Mak.  The signal strength was greatly improved over the internal antenna.  However, it is picking up noise which I believe is produced by the LCD display and its associated circuitry.  The lead connecting to AN1, which I think is the 'hot' lead, seems to be the one picking up the noise.  I played with the routing and the length of these leads, but could only slightly improve the situation.  Even tried a short piece of litz headphone cable for the internal routing.  Though not truly shielded, with this cable the AN2 lead closely hugs the AN1 lead.

The noise is an audible whine.  On a stock PL-380, as with some other radios, this can be heard on a weak MW station by grasping the top of the radio, apparently conducting the noise to the ferrite antenna.  Furthermore, I believe this noise confuses the Si4734 AGC, worsening the 'pumping' audio level which I find to be a common annoyance in DSP radios.  I was hoping the stronger signal would actually alleviate this. 

For now, I've reconnected the internal ferrite.  I wonder why the stock coil and its leads do not pick up the noise as much?  Maybe because of its lower impedance? 

Any ideas/comments are welcome!    A few more details below, for those interested:

• Coil wound with 10/44 Litz.  Not ideal, I know, but its what I had on hand to experiment with, and has worked nicely on passive ferrite antennas I've made. 
• About 120 turns, spread over about 60% of the 8-inch ferrite length.  Lots of turns, since R40C1 has lower permeability than Amidon 61.  My coil was checked by an RF engineer on an HP induction analyzer that cost way more than my car.  At 1MHz:  430 microhenries, Q=400. 
• My coil is wound in the same direction as the stock coil, though I don't know if this is called a left-hand or right-hand helix, or if that would affect noise pickup anyway.
• PL-380 purchased late 2018, SN: 36920181006731

Gary Thorburn