Connection TITAN 425-DRAKE TR7 / PS7. Help!

Discussion in 'Amateur Radio Amplifiers' started by IU3IPZ, May 21, 2019.

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  1. IU3IPZ

    IU3IPZ Ham Member QRZ Page

    greetings to all friends of QRZ.COM.
    I have a question ... maybe even two: I don't understand how to connect the Drake to the Titan (2nd series).
    In my (for example) p.a. I don't have the PTT / VOX jack (RCA)!
    I have three sockets (RCA): two key-ins, one key-out.
    In the Drake (on PS7) I can't use the vox socket because I connected the SP 75. I have to use the socket (very particular!) Vox-rly? What kind of cable to use? And ALC connection is mandatory?
    I try to send some photos.
    Thanks for your attention and sorry for my English .... yes there is Google but it is not always correct!
    Best 73' de IU3IPZ Giuseppe (

    Attached Files:

  2. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Looks like someone modified the TR-7 to provide the VOX RLY connection to an RCA phono jack that normally had the PSU voltage present there to provide power to small 12Vdc accessories.

    Confirm that just using an Ohmmeter. Key the TR-7 PTT and see that the phono jack connection goes from an open circuit to a short circuit (pull to ground) when the TR-7 is in "transmit." If so, all is good.

    Use the KEY IN phono jack on the Titan to key the amplifier by connecting a patch cable from the TR-7 VOX RLY connector to the Titan KEY IN connector. You might try each KEY IN connector, one at a time, to determine for sure that the amplifier keys properly when the TR-7 does.

    You can ignore the "other" KEY IN connector, and also the KEY OUT connector, when using a non-QSK transceiver like the TR-7. It's not QSK anyway, so that loop keying circuit in the Titan would not be used.
  3. IU3IPZ

    IU3IPZ Ham Member QRZ Page

    'Hi, thank you. I don't know if it has been modified because it is second hand (I have no news from the previous owner). I didn't write with the black pen.
    Why is PPT / VOX not marked on Titan?
    When I'm at home I try to check the radio.
    I found the Ten Tec scheme but it doesn't help me :(
    AH, the vox / rly connector is located on the PS7 power supply.
    Thanks, maybe someone can send contact photos
    Ten Tec / Drake 7 line on the rear panel.
    73 '
  4. W1QJ

    W1QJ Ham Member QRZ Page

    Yup Steve is right. Somebody disconnected the 13.8vdc output and made it a vox connection for the amplifier. Just run RCA cable from there to key in on the Titan. Either key in should work they are in parallel one has a resistor in series. The Titan does not need much more than 50 watts for full output so you may want to use ALC for protection as I don't believe that amp has a traditional grid trip circuit.
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Only DRAKE used that designation; nobody else did that I know of. For DRAKE gear (only) the amplifier keying line was labeled that way. Almost everyone else would label it "AMP" or "AMP KEY" or something else. The label doesn't matter. Ten Tec labeled it exactly as it should have been, which is KEY IN.

    Normally you would connect the VOX RLY connector from the 2-pin jack on the PS-7 power supply to key the amp. That gets its wiring through the fat cable and the big multipin connector on the back of the TR-7.

    The Ten Tec "scheme" is very simply. USE THE KEY IN jack connected to the VOX/RLY jack on the drake, observing which pin is chassis ground.

    I have a TR-7 and I've had a Titan amp and that setup took me about a minute.:)
  6. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    The ALC is compatible with the TR-7.

    But the TR-7 calls this connection "AGC" (another weird Drake designation) -- but it's ALC and the Titan will control it fine.
  7. IU3IPZ

    IU3IPZ Ham Member QRZ Page

    Well, now it's better. Ok, it's not difficult ... for those who can do it :) ;)
    So, the ALC is better to connect it, but is it an option? Would it work even without this contact?
    I can try, then the KEY IN connector, OK.
    He never had a p.a. and I don't have the PS7 / TITAN connection cable (VOX / RLY-KEY IN TITAN) I don't have the "mini plug" for the PS7 2-pin jack. I have to search or "build" and connect everything.
    Let's see in the coming weeks if I can complete the contacts. Thanks, grazie, danke, merci.
    All the best, 73

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