Many thanks to SWLing Post contributor, Rolf Snijder, who writes:
I have added an external antenna capability for mediumwave on the XHData D-808.
Simply add a 27 pF capacitor on the backside of the PCB on C10 to the the ferrite antenna.
The mod causes no loss on FM or shortwave!
I also replaced the Ferrite antenna with a bigger one so I now have more performance on MW!
Longwave is not good in my radio, even with an external antenna, it is not performing well.
Thanks once again, Rolf! I must assume that the Digitech AR-1780 could be modified in the same way as the radios appear to be near identical. Perhaps someone can verify this at some point!
I’m so happy that I even received North Korean signal at 819 kHz during wee hours of DYVL Aksyon Radyo and DXUM UMBN Davao with this mod.
Here is the video.
https://youtu.be/3Of2tzGZ6Ww
F4FEY version is different. It was coiled the wire to the ferrite and the wire is connected to red wire which is connected to headset jack and then connect the wire to the antenna jack’s metallic part by soldiering
Here is a mod in which external mediumwave antenna for Sihuadon/Radiwow R-108: https://m.youtube.com/watch?v=-yjHPVKqi9k.
I noticed NHK Akita 774 was received in Tacloban at nighttime thanks to modification that F4FEY did for XHDATA/Sihuadon d-808, this time for Radiwow/Sihuadon R-108
Tengo una XDATA D808m, dónde podría ver cómo queda la conexión exterior? Y, me puede explicar la forma de colocar una ferrita más grande y su construcción? Gracias.
I made an input for connecting external ferrite antennas.
Here, in my storage, you can see the reception of the Philippines 1611kHz –
https://yadi.sk/i/hIYBowRLQG0zdQ
Here, the XHDATA D-800 receives Mongolia radio in the LW band. –
https://yadi.sk/i/NuHuwZsNGD-oIw
I live in Novosibirsk (Russia)
I wonder if there is a simple way to remove the muting between tuning? My Sangean ats-909 was a simple snip of a wire…. any thoughts?
I haven’t seen schematics of the D-808 and so I was wondering, electrically, what does this modification do? How does it achieve the use of the external antenna jack for MW?
I think the capacitor act as DC blocker. The input from the jack goes also to the ferrite (Inductive coupling). So I think it works only with external loops and not with E-Field Antennas (?) Hope Rolf can clarify.
This is excellent… thanks, Rolf! My own D-808 will be opened up for these mods in short order.
One nice thing about the SiLabs DSP radios is that you don’t have to have the inductance of the ferrite loop exactly spot-on. The DSP chip automatically peak-tunes for each MW frequency, and I believe that the suitable inductance range for the coil is 250-400 uH. (Exact info is found in the SiLabs datasheets.)
Gary DeBock of Ultralight radios fame discovered this a couple years ago too. This characteristic is one that makes DSP portable radios easier to work on for medium wave antenna upgrades.
I made an input for connecting external ferrite antennas.
Here, in my storage, you can see the reception of the Philippines 1611kHz –
https://yadi.sk/i/hIYBowRLQG0zdQ
Here, the XHDATA D-800 receives Mongolia radio in the LW band. –
https://yadi.sk/i/NuHuwZsNGD-oIw
I live in Novosibirsk (Russia)