[Amps] Alpha 87A troubles with fault 17

Paul Christensen, Esq. w9ac at arrl.net
Sat Jan 24 12:58:07 EST 2004


> > 850 ,870 ......They ALL have overshoot on the leading edge big time
> > ......The Yaesu 1000MP series and FT-990 do not ..

However, the FT-1000 genre of transceivers address the leading edge
overshoot issue through the use of a fast ALC response time.  What's the
negative side-effect?  CW clicks due to an unusually abrupt and fast leading
edge wave-form.

The trick that the majority of manufacturers have not found yet, is a way to
minimize power spike overshoot without destroying the original keyed wave
form.

W8JI has published keying mods for the FT-1000 series transceivers and I
have published a mod for the Ten-Tec Omni 6/6+.  If we can figure out how
it's done why can't the manufacturers?

And the problem is not limited to CW, ALC overshoot is a problem on SSB,
particularly at power levels at less than 100% of the radio's capabilities.
Some radios allow the operator to independently adjust drive level, and this
certainly helps but it is not a perfect solution.

-Paul, W9AC



More information about the Amps mailing list