Wednesday, July 13, 2005

E QSO Computer to Ham Rig Interface Card

We are presently making a Interface Card for trial based on a circuit below designed by Peter G4KQU.
For those who would like to make their own cards suitable for their rigs, more information is available at the link below:

Components for Circuit
3 x 1k ¼ watt resistors
1 x 1.2k ¼ watt resistors
1 x 1k Potentiometer lin
1 x 2.2uF 50v capacitor
3 x 0.01uF capacitors
2 x (T1 & T2) 600 ohm transformers type 9000 RS Number 208-822
1 x IC1 optocoupler 4N25 RS Number 597-289
1 x Red LED (High sensitivity type)
1 x Diode 1N4148
2 x 3.5mm Stereo plugs
1 x 9 Pin D plug ( Com port 1 or 2) & cover
Screened cable - Project Box



  • It will be good if possible to provide information where to get the parts at local shops. Example the 600ohm transformer. I think Farnell is selling about RM35.

    By Anonymous Anonymous, at 1:35 PM  

  • LW,
    Most of the components can be obtained from any normal electronic shops, with the exception of the 600 ohms isolation transformers.
    I had to buy 2 Aztech 56K modems, just to remove the isolation transformers for our use. Modem costs RM23 each.
    RS at Glenmarie Shah Alam is selling it for RM23.75 each transformer.
    We are looking for a cheaper type costing less than RM10 at KLANG!
    Yet to confirm if this transformer can be used for our Interface card or not.

    By Blogger 9W2SSJ, at 2:29 PM  

  • This comment has been removed by a blog administrator.

    By Blogger Rodney Yeo @, at 11:28 AM  

  • SSJ,

    Here is the RASCAL "Radio And Sound Card Audio Link" by K4BAT.

    It is sold in ready made kit. It was bought by 9W2LW LikWei.

    He posted the diagram with the parts lists at sometime last year.

    This is the same schematic diagram which is sold by

    Maybe you could consider trying this version which has been proven working by 9W2LW.

    Just an though...



    By Blogger Rodney Yeo @, at 11:32 AM  

  • Sorry for the typo error...

    Malaysian Amateur Radio

    By Blogger Rodney Yeo @, at 11:35 AM  

  • Photo(homebrew)available at my website at

    By Anonymous Anonymous, at 7:43 PM  

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