Hi Paul, Just plugging in a mono plug by itself is not detectable in firmware. The protection kicks in as a result of a brief spike in AF amp current drain. To observe this you need a mono plug, SPKRS=2, and moderate to high volume setting with a strong signal in the passband. This will eventually cause the AF amp chip to draw 1/2 to 1 amp of current on peaks, which firmware can easily spot.
I wouldn't suggest forcing this condition intentionally. We tested it on several K3s, and we know it works. But it is intended as a safety feature, not as a substitute for using a stereo speaker plug when SPKRS is set to 2. 73, Wayne N6KR On May 21, 2009, at 7:54 AM, pd0psb wrote: > > Anybody else tested this? > I can't get speaker protection to work. > Or does it only work with higher AF levels? > > 73' > Paul > PD0PSB > > > MCU 3.14 / DSP 2.16 May 9, 2009 > > * SPEAKER PROTECTION: If you’re set up for stereo speakers > (CONFIG:SPKRS = 2), but insert a mono speaker plug, the right > speaker output will be shorted to ground. This can cause excess > current drain if you turn volume up to high levels. The K3 now > detects this condition, automatically turning off the right > channel (and briefly flashing "SPRKS=1"). (It would be better, > of course, to use a stereo plug if you set SPKRS to 2, rather > than wait for the firmware to detect the mono plug.) --- http://www.elecraft.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
