Analog ALC is a fully closed loop too. And Elecraft measuring the output and
generating feedback isn't without flaw either. There is an ADC in that output
measurement system that introduces low-level power jitter easily observed on a
spectrum analyzer.
Wes N7WS
On 6/28/2019 12:04 PM, Don Wilhelm wrote:
Brian,
ALC should never be used for power control doing so usually causes RF
compression and distortion.
Many of the digital application instructions tell you to set for NO ALC as a
*maximum* audio level, set the power control for the maximum desired and then
reduce the audio level to reduce the power - I think that is why the slider in
WSJTX is labeled POWER when it is really an audio level control.
The above method works fine for many transceivers, but NOT for Elecraft which
measures the actual power output, compares it with the set power and adjusts
the RF drive accordingly. This is a fully closed loop system. As far as I
know, Elecraft is the only amateur transceiver using that type of system.
With Elecraft transceivers (except for the K2), adjust the audio drive level
to produce 4 bars solid on the ALC meter with the 5th bar flashing (this is
the NO ALC point. Then leave it that way and adjust the desired power with
the power knob. Doing otherwise will result in low power at the start and
power hunting as the transmission goes on.
73,
Don W3FPR
On 6/28/2019 2:38 PM, Brian Denley wrote:
I have always thought that ALC is not appropriate for power control. It’s a
protection system. Over use of ALC acts like compression. No?
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to wes_n...@triconet.org
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com