Hi gang, Apart from the fundamental discussion "do you really need ALC yes/no", I have raised this issue already quite some time ago. I have an SPE 1K-FA and K3 on order, and I want to work both full power barefoot as well as with the amp, but do not want to run the risk to accidentally overdrive it. A very quick response from Wayne gave the following info. Sufficient to cool the discussion for a while I would say ... -- Enno, PF5X <quote>
From: wayne burdick [EMAIL PROTECTED] Date: Fri, 12 Oct 2007 14:12:24 -0700 To: [email protected], [EMAIL PROTECTED] Subject: regarding external ALC Hi Enno, Transmit power control via the ALC input (AUX I/O pin 15) is planned, but not finalized. We're mindful of the negative impact ALC can have on transmit signal purity, a subject of recent debate within testing organizations. External amplifiers vary widely in their loop gain, causing problems with distortion. Many amplifiers, like the Alpha 87a, specifically say not to use external ALC. A properly operating, internally ALC controlled rig like the K3 does not need external ALC input to connect to an external amp. In general, external ALC should -not- be used as a way to control rig power. As for the voltage range, this is not a typo: the ALC input handles 0 to +5 V. Once ALC is working to our satisfaction, we'll provide simple interfacing information that will allow the use of negative control voltages (probably a resistive divider pulled up to a positive supply, or at most an op-amp circuit). Meanwhile, the K3's DSP-based early-stage ALC is very effective at preventing amplifier overdrive, and should suffice in nearly all cases. 73, Wayne N6KR <unquote> No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.16.13/1167 - Release Date: 03-Dec-2007 12:20 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
