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Re: [tracker2] FC-301 power command

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  • Keith VE7GDH
    djinni442 (callsign?) wrote... ... Straight from the FC301D service manual... Operation Rating... Intermittent 5:5:90 ( TX: RX: Standby) In the case of the
    Message 1 of 2 , May 25, 2009
      djinni442 (callsign?) wrote...

      > I have one of the FC-301 boxes w/ integrated tracker2. Curious about
      > constraints with the setpower command. More specifically, is there any
      > info out there on xmit duty cycle versus setpower? Ie if "42" would
      > allow for x seconds per minute, "99" would allow for 1 second a
      > minute etc.

      Straight from the FC301D service manual...

      Operation Rating... Intermittent 5:5:90 ( TX: RX: Standby)

      In the case of the T2-301, the "receive time" will depend on how busy
      the frequency is and I assume will be insignificant as far as heating of
      the whole unit. Assuming the above is in seconds, APRS transmissions
      aren't 5 seconds long... more like half a second. With SmartBeaconing,
      you probably won't be beaconing more than every 60 to 90 seconds
      when going in a straight line, and only then at highway speeds. I use
      60 seconds for the fast rate, but where I live, I can only drive at
      highway speeds for 2-3 minutes at the most. Only if you continually
      drove in circles would it be a problem, depending on the turn angle and
      minimum time between transmissions... e.g. you might have it set to
      beacon when it turns 25 degrees but no more than every 10 seconds.
      Unless you are burning doughnuts in a parking lot, most turns will only
      be a 10-30 seconds in duration. If you continually drove in circles with
      "normal" SmartBeaconing settings, you could exceed the transmit duty
      cycle.

      My observations with SETPOWER... with the lid off the T2-301 I've had it
      go on continuous transmit with SETPOWER 99 when I was experimenting with
      it. I've also had that happen when the antenna had a high SWR. My normal
      setting is SETPOWER 42, but do have mine set at 60 right now. I should
      measure the output power. Don't assume your antenna is good. Measure the
      SWR. I discovered a problem when the T2-301 went mobile for the first
      time. The antenna was checked and the SWR was low. When it was all
      buttoned up when it went for a drive, it was only heard until it was
      about (less than) 1 km away. On the second test, it wasn't heard at all.
      Listening on another radio, the tones were rough and distorted, They
      couldn't be decoded. It was shut down and torn apart. The BNC connector
      on the end of the cable was bad. The final determination was that the
      center conductor wasn't making good contact. The fix was to grab the
      center pin and pull it further into the BNC shell. It "clicked" into
      place and passed the "wiggle" test afterwards with a low SWR.
      It hasn't been mobile again yet though.

      73 es cul - Keith VE7GDH
      --
      "I may be lost, but I know exactly where I am!"
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