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help me fix my sennheiser wireless system

Discussion in 'Radio and Communications' started by Jozee, Feb 8, 2017.

  1. Jozee

    Jozee New Member

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    hi all,
    I have an old wireless system which includes a pocket receiver, a pocket transmitter and a handheld transmitter.
    i'm having a bad reception and dropouts.
    let me start by saying that the pocket receiver and transmitter was missing its original antennas and i made two antenna at the exact same length as the handheld original antenna.
    the dropouts accruing with both the handheld and the pocket transmitters so I'm guessing that the problem is with the receiver.
    I know that this is an old set but its in really hi quality and it will be sad for me to throw it away.
    can you please tell me where to start?
     

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  2. Les Jones

    Les Jones Well-Known Member

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    Looking at the pictures of your antennas they look like the are made from coaxial cable with the screen still in place. If this is so then they will not work. (Unless they have been made in the form of a coaxial dipole.)

    Les.
     
  3. RadioRon

    RadioRon Well-Known Member

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    Can you provide more information about exactly how you made the antennas?
     
  4. dave

    Dave New Member

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  5. MikeMl

    MikeMl Well-Known Member Most Helpful Member

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    Shielded antennas are about as useful as underground antennas...:D
     
    • Agree Agree x 1
  6. Jozee

    Jozee New Member

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    Hi,
    Do not worry, the antennas are not shielded :)
    I have used a simple wire and solder it only to the middle socket, the shield screw is untouched.
    what else can be wrong?
     
  7. Mikebits

    Mikebits Well-Known Member

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    It's kinda like putting your antenna inside a metal box. Why do you suppose car antennas are on the outside?
     
  8. Jozee

    Jozee New Member

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    I know that and as i said the antennas are not shielded. thanks
     
  9. RadioRon

    RadioRon Well-Known Member

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    Do you only get dropouts when the units are moved far apart? How far apart? When the units are close together so that there are no dropouts, is the audio quality good or is there unusual noise or distortion?

    What is the condition of the batteries? How do you know this?

    When was the last time that these units worked properly? Did you operate them then, or have you never seen these working properly?
     
  10. RadioRon

    RadioRon Well-Known Member

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  11. Jozee

    Jozee New Member

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    Hi,
    the dropouts occurs after 10-15 meters, i'm sure those units used to work perfectly since its a very professional product, but its 15 years old so some parts may net function as the should be.
    batteries are fine, i have some electronic knowledge. not RF though.

     
  12. RadioRon

    RadioRon Well-Known Member

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    Can you elaborate on what you mean by "dropouts". To me, this word means that the signal becomes too weak and the receiver no longer hears the transmitter. In FM systems, there is often a Squelch function that determines how weak the signal can be before the audio is muted. I suspect that in your microphones, when the dropout occurs the audio simply disappears. If so, then your squelch function is working. In some systems where squelch is not used, the audio would become very noisy or be replaced by noise, so this would not sound the same as a complete dropout. The level at which the squelch function does its muting is adjustable. This raises the question of whether anyone has touched the adjustable components in the transceiver. Have you?
    When you are close enough, is the audio normal or distorted?
    What range do you expect to get when the system is working normally?
     

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