ad: BigSignal-1

FT817ND Only powers with Ant conntected

Discussion in 'General Technical Questions and Answers' started by M6WCL, Jun 14, 2018.

ad: L-HROutlet
ad: l-rl
ad: Left-3
ad: MessiPaoloni-1
ad: Left-2
ad: L-MFJ
ad: Subscribe
  1. M6WCL

    M6WCL Ham Member QRZ Page

    My FT817ND has developed a fault where it needs to have the antenna plugged in else it powers off. It also seems to be ignoring the key when it is connected.

    Has anyone got any ideas of where to even begin with diagnosing this?

    I tried a factor reset and it is still the same!

    Thanks and 73
  2. G6YYN

    G6YYN Ham Member QRZ Page

    Is it a mobile installation?
    If it is check the negative connection on the power lead, it could be using the coax outer as the negative connection. Also examine the end of the power plug, they break right at the tip and sometimes leave a bit if insulation inside the radio.
    KB4QAA, KU3X and KC8VWM like this.
  3. AA3EE

    AA3EE Ham Member QRZ Page

    On the non-ND, the power leads go through a toroid (noise filter) before connecting to the board. I just fixed one where one of the windings in the negative lead, and a trace on the board opened up. I only had the DC plug in. If I would have connected an antenna that shared a ground (albeit a long path) with the power supply, I bet it would have turned on.

    Download the service manual and check from the DC jack on the back through the first few traces of the negative circuit on the board.
  4. W0IS

    W0IS Ham Member QRZ Page

    Yes, I suspect there's a break in the negative power lead, and it's grounding through the antenna shield.

    As for the key being "ignored," I forget right off hand, but I believe there's a menu setting that configures the key plug depending on whether you have a straight key or paddles.
    KU3X likes this.
  5. M6WCL

    M6WCL Ham Member QRZ Page

    Thanks for the replies everyone. I will check the negative lead as this does sound likely.

    Just to clarify it is not a mobile installation and it is the ND version.

    I have checked all menus for the key. I do have a feeling it is somehow related. I guess I will find out if I manage to resolve the turning on issue.
  6. M6WCL

    M6WCL Ham Member QRZ Page

    I have been working on testing this out.

    There is no issue with the lead as I have checked the voltage on the board side of the DC jack and I get the correct voltage. There is nothing visibly different with the board.

    If I plug an antenna in I can use the outer (or indeed any of the metal housing) as the negative to measure voltage. If I remove the antenna then the voltage slowly ticks down to zero again. The whole time the DC jack is giving the correct voltage.

    Any ideas?

    Edit: it all works as normal using the internal battery pack
  7. KP4SX

    KP4SX XML Subscriber QRZ Page

    I had a similar problem with my Icom. I have a inline 12v protection device and one of the PowerPole pins was pushing back (negative)

    Sounds like you have a high-R connection on the negative side.
    Last edited: Jun 16, 2018
  8. M6WCL

    M6WCL Ham Member QRZ Page

    The resistance is same on both the positive and negative lead as measured from the board to the powerpole connectors. I can't think what else would be causing this
  9. KA9JLM

    KA9JLM Ham Member QRZ Page

    What does that mean ?

    Is the radio set for Auto Power Off ? APO
  10. N3PM

    N3PM Ham Member QRZ Page

    I have a schematic for an ND model, and it shows the power input toroid that AA3EE refers to. Try an external 12v battery and see if the "antenna connected" fixes it. If no 12v battery is available, try any antenna that has no ground involved. Only a few things from 12V in to the rig. The jack, some PCB traces and the toroid. Or, try jumping the PSU negative directly to your rig's ground lug.
    Mike N3PM

Share This Page

ad: UR5CDX-1