Is my VTX dead? I crashed the quad and this happens now

Discussion in 'FPV Systems' started by Mehigh, Jun 18, 2017.

  1. Mehigh

    Mehigh Member


    So yesterday I went for a flight with my quad, and I flipped it in the air and crashed it right onto the VTX, the antenna joints broke and I did the soldering back. The problem now is that once the VTX gets a little hot it messes up the image. When I change band and channel on the VTX, it doesn't change at all, it is stuck on E-3, although the leds show that the channel has been changed, the FPV goggles only get the image on E-3. Is it dead? :(



  2. Gyro Doctor

    Gyro Doctor Electronics Tech for over 45 years

    I'm afraid it is more than likely fried.
    You see, the final output stage of the amplifier in the transmitter expects to see a load (the antenna) that will dissipate the energy.
    If the connection breaks then all that energy is reflected back into the amp and smokes it and often the rest of the circuitry too.
    The same thing happens to most any transmitter when their antennas have problems or are disconnected, including your RC transmitter.
    mozquito1 likes this.
  3. mozquito1

    mozquito1 Well-Known Member

    That blow backs a biatch.
    Two of my quads are on pigtails for that reason. I mounted the vtx so it stick out the back, not on top. I have found that receivers are OK to run without an antenna, by mistake.
    Gyro Doctor likes this.
  4. Gyro Doctor

    Gyro Doctor Electronics Tech for over 45 years

    Yep, receivers aren't generating any power, they're "just listening" and without a connected antenna it's just really quite out there ... lol ...
    any TX, on the other hand, tends to "let the magic smoke out" :p

    I used to make some decent money "replacing finals" in and "peaking" of CB radios back in the day and (for a little extra $) could get you about
    15 watts (instead of 4, as per regs) out of a stock radio :) I just loved those under the dash slide-in brackets they used to sell because the crappy
    electrical connections they'd make would often smoke people's radios and keep me plenty busy ;)
    Last edited: Jul 7, 2017
    mozquito1 likes this.
  5. dragger201

    dragger201 If it ain't broke, don't fix it??? You kidding?

    I don't want to see(and haven't yet)..............I feel for anyone who has had it. But I gotta tell ya............I love the terminology..........

    And of course.........if this was 1967 instead of 2017..........that's a whole 'nother reference...........
    mozquito1 and Gyro Doctor like this.

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