[1000mp] More Key Click Comparisons

[Bob Henderson]

Further to my earlier posting, I have now reviewed the W8JI mod and the
Inrad mod for the MP and find the Inrad mod to be essentially the W8JI mod
but without the select on test components.

First I tried the Inrad mod which provided a significant improvement.  Next,
I tried the W8JI mod and selected components on test.  The results have been
added to my test table below.

Finally, I consolidated my W8JI mod  in the form of the Inrad mod but using
the values selected on test.  In my case a 68k resistor in parallel with a
47nF cap placed across C2148 on the underside of the IF board provided an
equivalent result to the full W8JI circuit.  I did add the 100nF cap to the
RF board too.

My old MP now looks cleaner than anything else I tested except for the 870
set at 8 mS.  He's a clever chap that Tom Roach!

TS930                          1.6 kHz
TS870 (2mS)               2.0 kHz
TS870 (4mS)               1.5 kHz
TS870 (8mS)               1.0 kHz
K2                               1.5 kHz
MP MkV Field             2.0 kHz
MP                               3.4 kHz
MP (Inrad mod)           1.7 kHz
MP (W8JI mod)           1.3 kHz

73

Bob 5B4AGN, P3F