Here is what I do for smooth as silk, spike free low power excitation for my
single 3-500Z deck:
The rigs are a Kenwood 820S, 830S, and 930SAT. For all three I enable the
speech processor (all use an RF design and hence this method I will describe
does not work with most audio derived speech processors). Set the processor
for the desired level of processing. Then decrease the 'mic gain' control
until desired power out is reached. I whistle at a constant tone and
amplitude (my human whistle is calibrated against a HP 200CD so I know it is
PERFECT) and then just watch the output drop. Smooth as silk and the output
power never spikes up above the desired value. This method would would with
any rig using an RF derived processor.
Lane
Ku7i
>
>I see Jan's point - if your normal signal is operating around 1500W with a
>tube such as a 4CX10000 which can handle the leading edge spikes generated
>by some of the modern radios, less splatter will be generated.
>
>However, I don't think that is really the problem:
>
>SYSTEM ENGINEERING - Matching the exciter to the amplifier. As Tom points
>out, running a 100W radio at 10W sometimes creates a new set of problems.
>Transceiver output power and nominal amplifier drive should be reasonably
>aligned. Using my 200W FT-1000D to drive my Alpha 91b (nominal 40W drive)
>is touchy. Using the same radio to drive my 15M 3-1000Z wart hog is smooth
>as silk. My friend W8WD has a FT-1000MP and an Alpha 89 - there is a
>switch on the 'MP to reduce the drive to 50, which results in real smooth
>operation with the 89.
>
>SSB CONTROLS/LEVELS - How many amateurs really know how to set the controls
>on their SSB rig? In the absence of a RF limiter in the radio, the mic
>gain is all you can adjust; turn it up too far and some downstream stage
>will flat top and splatter. With RF limiters/clippers, you have MIC GAIN,
>and sometimes IN and OUT (or DRIVE) controls. The mic gain controls output
>power to a point, then the limiter takes over. If the output level from
>the limiter is too high, you can have downstream stage splatter again. If
>the output is too low, the final output is low no matter how high you jack
>the mic gain and your signal sounds like junk. Maybe no splatter, but its
>still garbage on the bands.
>
>That's the great thing about CW - fewer controls to worry about and unless
>the rise/fall times are out of whack, few ways to generate a truly bad
>signal.
>
>73,
>
>Dave/K8CC
>
>
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>
>
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