MKU UP 2424 back after repair/modification

  • Hi Frank

    thank you - i am courios what version the "new" 2424B has.

    Did you try if you can switch the LO to 4 ,5, 6 or 7 ? If "yes" then maybe also an input in 70cm band is possible - like in the 2424B.....but that's just speculation ;)

    73, Johannes

  • I will do some tests in the next few days. In addition, I had also reported other software issues to the manufacturer and I hope they have been fixed in the current release.

    In any case, FM'ing no longer seems to exist and the overlong threaded bolts on the DATA jack have also been replaced.

  • Did my first tests with repaired/updated MKU2424A:

    - Software version now is 2.0

    - New LO frequencys available: 1968, 1967, 1966 and 1965 MHz

    MKU2424A now works with 2m and 70cm IF (i have tested both)

    I hope that the other problems have been solved as well:

    - PTT (after "P1" command) has been reset by RF VOX

    - RX/TX-LED lights up green after "P0" command (but device OFF)

    - Sometimes the TEMP-LED lights up (but device cold)

  • Al aire libre

    Me too. I also can test via serial port version is now 2.0. Can change LO also to 1968 Mhz..which gave me 432 Mhz in my FT 818..perfect on the satellite for my uplink. MKU2424A was only 144 Mhz capable. Checked my TX against my LNB TXCO and also with SDR console 3.09 "anti-drift". All seems stable and perfect even without the external LO. (BTW mine was sent back after fixing also without external LO connector),.Waiting for further documentation from Kuhne... But I can expect it´s OK and fixed. Right.


  • Drift of my TX setup with repaired/updated MKU2424A (without 10 MHz reference) and FT-817 (build in TCXO, IF=145 MHz):

    - After 30min warm-up (RX only) the drift is -250 Hz

    - After 5min TX with constant 20W it drifts further -100 Hz

    - After 10min TX with constant 20W it drifts further -50 Hz

    - After 15min TX with constant 20W no more significant drift

    Conclusion: After the warm-up phase the frequency should be reasonably stable for most operating modes. This is ok for me.

  • Hi @ll,

    I also got my repaired/upgraded KMU UP 2424 A back a few days ago. But I am still missing the updated manual concerning the REF input. In the meantime I upgraded the case and added a SMA/UFL pigtail.

    Did anybody test with an external reference yet?

    vy73 de Florian DF2ET

  • df2et Hi Florian, well done!. The new installed reference input connector looks really good.

    I did not open-up my modified converter yet, but thanks to your clear pictures I can see how the two side halves are separated. So, only unscrewing the 2 lower frontpanel + 2 backpanel screws will make the sides to separate, I guess?.

    Anyway, I am very happy with the modification as the standard stability, without external reference, seems sufficient for most work. Hope that Kuhne will provide soon some information about this extra feature. I will probably make use of it later.

    73 Ed PA1EW

  • Hello,

    I just REF-locked my updated MKU UP 2424A (now "B" ;) ). Seems that the 10 MHz signal has to have a certain level to lock. With my leo bodnar GPSDO in the lowest sigal level setting it locks about 80% of the time; with the second lowest level it locks 100%.

    (I connected a small coax with the free "mini-coax" connector - on the board from were already two coax cables go into the other module and mounted a SMA-jack in the rear (same position as in 2424B) of the upconverter.)

    73 de johannes

  • Hi Johannes,

    I did have a talk to the Kuhne guys at HamRadio in Friedrichshafen and asked for the details of the reference input of the modified MKU 2424 A converter. They referred me to the manual for the recent B version where you can read as attached in the image. See below. It also applies to the factory-upgradede MKU2424 A.

    vy73 de Florian DF2ET