Topband: W8JI FT1000D Key Click Mod-My Experience

[Roger D. Johnson]

  I noticed the same thing when installing the mod in my FT-1000D.
Putting an NPN transistor in series with the keying line means
that the switching diode is not reverse biased on receive. If I
remember correctly, the signal out of the balanced modulator is
on continously which could result in some leakage through the diode
possibly causing other problems. In the end I decide not to install
the mod as on the air checks indicated no problems with clicks.

  100 us seems like an awfully fast rise time although that IS the
time constant for the original components (R-3119 and C-3243). The
rise time on my rig with those components seems to be about 2.5 ms.
This seems to be too fast for click free operation so I'm going to
take some more measurements and revisit the problem. Perhaps changing
some of the original component values will result in a softer waveform.
The big problem now is that I was laid off from my job and don't have
access to all the SMD components and tools!

73, Roger

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