New uBITx: This is what you should not do!

Berenstain Bear tells the new uBITx owner:

  • Check and recheck every connection.   Wrong connections can result in major damage to your uBITx.
  • Check that you have your power supply wired around the right way.  There is little protection for reverse voltage mistakes on the uBITx withouth modification.
  • Check that you have not inserted the digital connector in the audio connector (or vice-versa).  This WILL damage your uBITx!   Mark these connectors now.
  • Do not power up without a 4.7K pull up resistor to 5v on the CW key pin.  Without this pull up resistor, the uBITx will arbitrarily go into TX.
  • Connect a 50 ohm dummy load, or a well matched antenna to the uBITx before attempting to transmit.  Failure to do will result in finals (IRF510s) that will blow up.
  • Do not touch any settings on the board. Boards are adjusted at the factory for correct operation. Do not adjust driver or bias pots, without having carefully read the instructions.  Over-driving the finals or setting abnormal bias levels can be catastrophic to your IRF510s.  Generally speaking, these controls should not be adjusted and do not require adjustment, even if you have read comments to the contrary on the email list.
  • Ask for help on the IO groups BITX20 list.  Fellow amateur operators are only too happy to provide assistance.

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