[Elecraft] Deaf K2 fixed ( SN 4620 )

[Steve Cooke]

Hello all ,

            I've just managed to fix my " new to me K2 " ... I had always thought it was less sensitive than it should be , and a check with an XG3 confirmed it .

The Symptoms .

Low sensitivity
Unable to get satisfactory S meter readings despite checking AGC volts and S Hi and S Low .
L34 on the RF board didn't have a peak in it .
Low audio out .

            All indicating low gain somewhere ..but where ? !  I changed U12 ( MC1350 ) I.F. amp which improved it a bit , but the real culprit was on the SSB board . 
            RFC 2  is squeezed in between X7 and RP2 , and the enamel insulation on RFC2 had been damaged . This resulted in providing a DC path to earth via the can of X7 ....which played havoc with the voltages on the switching diodes D6,7,8,9 . Replacing RFC2    resulted in a much livelier RX , the S meter works properly and L34 peaks up properly...... life is good .

            Whilst doing the DC checks , I couldn't find any reference in the manual to the expected voltages on Q25 on the RF board ....didn't need them , but just wondered if I had missed them somewhere .

                                                                73 steve G1MPW