Perfect pop and click fix for CW only operators

Tom Cooper
 

I tried all the mods using 2n7000 switches and such, and found that the improvement always fell short of headphone usable.  I only operate CW and this mod removes the source of the problem, but disables the mic amp in the process.

The leading edge pop you hear when going from R to T is caused by current inrush to C64 (Q6 mic amp power) when the TX voltage is turned on by K1.  Removing R66 eliminates the pop completely, but the mic amp no longer works.

The click you hear when going from T to R is caused by the inrush current to C52 (Q70 AF pre-amp power) when the RX voltage is switched back on by K1.  Cutting the trace bringing RX voltage to R52 and connecting R52 to +12V keeps the AF pre-amp constantly supplied and eliminates the click.  There is a little noise from the RX voltage returning to other parts of the receiver but it does not bother me enough to find a fix.

I am now operating with no additional VE1BWV type anti-pop and it is a pleasure not to need it.

73,

Tom  W1EAT

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