Kuhne Up Converter needs a PTT connection !!!

  • Hi @ll,

    there are some stations with massive audio distortions using the Kuhne Phase-4 up converter 2424 B.

    It is mandatory to connect the PTT line to your transceiver!

    This is NOT a plug an play solution, you have to put out your soldering iron ;)

    The Kuhne equipment is always a good choice, but you have to use it in a correct way.


    Der Kuhne Phase-4 Up-Converter muss unbedingt an die PTT Leitung des Transceivers angeschlossen werden! Wenn das nicht geschieht, hört man massive Störungen im Audio Signal, besonders in den "leisen Passagen", ähnlich einer falschen Bias Einstellung bei Kurzwelle.

    Bitte liebe Steckdosenamateure, holt den Lötkolben aus der Schublade ;)

    Kuhne Equipment ist eine gute Wahl, man muss allerdings die Geräte auch richtig anschliessen.

    73, Mike


  • Thank you Mike

    Also the manual is clearly stating this requirement, mentioning that it can also be achieved by injecting +3 .....12 VDC to the inner conductor of the IF cable.


    1) I don't want o open my rig to carry out the proposed modification to inject DC; what can I do? (external solution)

    2) what if I leave the Khune constantly in TX while in RX on the receiving side?

    Thank you


  • hb9iiu Hello Daniel, I am using a Kuhne Up-converter for QO-100 as well and use a simple two-wire cable from the "TUN/LIN" connector on the transceiver, in my case a FT991A (this is ACC-conn on FT817, etc) . This cable provides a ground connection during TX, just as required for the Up-converter.

    This type of cable can be ordered here TechnoFix and just needs to be attached to the Kuhne-cable (White/Brown wires). Good luck!

    73 Ed PA1EW

  • Hi Daniel,

    a simple single wire cable from the PTT pin of the transceiver to the up-converter will be fine.

    Another option is that you use a bias tee to provide the PTT signal via the coax cable. This kind of power injector is used for the lnb power too. Just insert another one at the if-output of your rig which is connected to the PTT line.

    73, Mike

  • As a precaution with Bias-T option: do not exceed the maximum allowed RF power that the device can handle safely!. A few Watts from the driver transceiver will damage the common receive types of bias-T. Otherwise, this is very good solution for remote control over longer distances.

    73 Ed

  • Thanks All!

    The Bias-T solution is exactly what I am looking for to avoid additional cables. The issue is, as mentioned by Ed, the admissible RF Power of the common ones found in the market. Difficult to find data, but for the ones I found, they were only able to handle 500mW. Will look around for a DIY solution, or perhaps a small radio remote solution on 433 Mhz.



  • hb9iiu

    if you are looking for a remote conrol solution, you could take a raspery and connect it via serial with the Upconverter and via WLAN with your home network. Than you can (e.g. via TeamViewer) remote controll the raspery and with a terminal program you can communicate with your upconverter and switch between TX and RX (and also on/off, forward and refleted power, IF readout and IF change....)..

    73 de Johannes

  • Many thanks Johannes

    I actually already have prepared something in this direction, but based on an ESP8266 Wifi Arduino module with RS3232 (3 Volts) level converter. The device is hosting a webpage as shown below (sorry for the WSVR spelling mistake).

    At the moment I am facing 2 issues.

    I get strange values for FWD and REF power (see here :

    Strange results from KUHNE Up-Converter data port)

    Second, the Kuhne is very slow in replying to requests via the serial port so that I will have to program some average filters for the Power and VSWR bar-graphs.

    The webpage is a combination of html, css, and javascripts.

    Have you tried to analyse what the Kuhne sends you back for FWD and REF when transmitting (antenna/dummy load)?

    Kind regards