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flex3000 wont switch on when cold. have to warm it up before it turns on.. help appreciated

flex 3000 club radio, not used ofrt and shack is a cold attic room.. when we do want to use it , we have to warm it up infront of a fan heater before it will switch on


  • JohnJohn Member
    edited June 2018
    I would think there are temperature specs in which the transceiver should be kept. Changes to temperature and humidity in an uncontrolled room will probably cause condensation to form on the inside and there may well be traces of corrosion on the electronics. I suggest you open it up and check for water damage first.
    The cure might be to install a heating element inside the transceiver up against the top cover, with a thermostat sensor to keep it warm
  • Neal_K3NCNeal_K3NC Member ✭✭
    edited March 2017
    Dave, how cold is 'cold' when you are trying to start it up?

  • Dave HerbieDave Herbie Member
    edited March 2017
    less than 10 degrees Celsius i would say... the first relay clicks but it does not start..
    i could put the heating on in the shack ,and come back in a short while to find the radio has started. runs fine once it has started
  • Neal_K3NCNeal_K3NC Member ✭✭
    edited March 2017
    I wonder if one of the relays is sluggish...
  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited March 2017
    I suspect John is correct that the ambient cold and humidity are responsible for the behavior you are seeing.  Take the radio to a warmer, less damp location and see if the behavior persists.
  • Dave HerbieDave Herbie Member
    edited March 2017
    ime going to bring it home and use it for a while. see how it does.
  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited March 2017
    That is a good plan.
  • Bruno BeckersBruno Beckers Member
    edited June 2019
    I just stumbled on this topic.
    My F3K has the same problem. If the ambient temp is below 16 degrees Celcius, it won't start FROM THE FIRST TIME.
    Indeed the first relais clicks but the blue light does not come on.
    If I leave it on for 10 seconds and then turn it OFF and ON again, all works.
    This 10 second period becomes longer if the ambient temperature gets lower.
    It can take 1 minute at temperatures of 10 C and below but it ALWAYS starts up at the end.
    Above 16C there is no problem and the F3K comes on at the first attempt.
    I have the impression there is some oscillator refusing to start when too cold. By appying VCC to the unit, the oscillator chip warms up and then works normally at the next attempt.
    I have my F3K for more than 3 years and the "critical 16C temperature" does not seem to change over time.

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