[TenTec] TenTec] TX EQ = -14 dB for PSK31

[Dr. Gerald N. Johnson]

On Fri, 2006-12-29 at 14:53 -0500, Mark DeBord wrote:
> I have found the ALC light not to be accurate unless the Orion I is set to 
> full output. For example, while you have the power set at 100, talk into the 
> mic and adjust mic gain until the ALC comes on only on peaks. Now, if you 
> reduce the power out while talking (leaving the mic gain alone), you will 
> see the ALC light become more active. If you reduce power down to 1 watt, 
> the ALC will come on solid on every word you speak.
> So, it would seem adjusting the mic gain with full output would be more 
> accurate for psk31 (or other data) work.
> 
> Mark
> 
That's because the ALC is what sets the power output. When you set the
power to a lower level that sets the ALC threshold to a lower level. If
you keep the gain the same then you have excess drive at that lower
level and so ALC has to reduce the gain somewhere automatically. You
should reduce the microphone gain proportionate to the reduction in in
power, or by the ALC light so at the reduced power the ALC light just
comes on on peaks.
-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer