[Kenwood] MC 60A and ALC settings with TS-940, please.

Thu, 10 Jan 2002 06:40:25 UTC

On Wed, 09 Jan 2002 13:20:12 -0800 Leslie Zwiebel <[email protected]>
writes:
>	What settings (low/hi impedance) seem to best match radio and 
>provide
>liveliest ALC metering? Also, the mic gain (ALC level) knob is very
>touchy, slightest touch makes big change. Audio-wise, what overall
>combination of settings on panel, and also inside radio have folks
>enjoyed best?

Les,

The 940s is fixxed at high imp input to the mic amp.  (universal)
Running a low imp mic will work but will modify the freq response and
it'll also require a higher mic gain setting.

Ideally you want a high imp mic and then you'll realize the full freq
response the rig can offer. Less whatever the mic can do.

The mc-60a works best if you attenuate the output from the element
to amp board.  About 6db down seems ideal. Esspecially if you run VOX.
See the handbook for t network attenuators...

For DX working freq response a simple R/C  1500pf in series shunted
by 50k ohm resistor will roll the lowend off nicely.

The ALC timing resistor (100ohms) should be changed to a 91 ohm 1%
metal film 1/8 watt unit.

ALC should be recalibrated to 3.2 volts +-.01 volts  -- CRITICAL

Your mic gain should be somewhere very near 1 on the scale.
Your processor IN also should be near 1 on the scale.
Your processor out should be about 3-5 and set ALC on threshold on all
audio peaks.  Generally once set the ALC action should be in the marking
ALC of the meter's scale, very few peaks will reach threshold or
midscale.

If you want to make the VOX behave better insert a bandpass filter 
in the VOX amp line coming from the mic amp. This canbe a simple opamp
design with 300-3000hz response.  This will eliminate for the most part
unwanted anti-vox operation esspecially with the omni pattern of the
MC-60A.  For best VOX operation you should use a cardioid pattern mic.

73,    Jerry                                     [email protected]
[text|uuencode|59kb ea]   No RFC #2048                                   
         'Y2K ?   Because 1k is 3 decibels down in amplitude. 9991
krr2ak'

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