XHDATA D-808 modification to allow an external mediumwave antenna

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!

Spread the radio love

6 thoughts on “XHDATA D-808 modification to allow an external mediumwave antenna

  1. Sergej

    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)

    Reply
  2. Carl Street

    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?

    Reply
  3. Mike

    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?

    Reply
    1. Ben

      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.

      Reply
  4. Guy Atkins

    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.

    Reply
    1. Sergej

      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)

      Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.