<<< It took me a copy of tries to make my point to get Wayne to make the change, but at V3.10 of the firmware, he made the following addition feature available:
CW VOX OFF BY DEFAULT ON POWER-UP: Some stations using PC control may inadvertently key the K3 in CW mode on power-up if VOX CW is in effect. If this is an issue at your station, locate the CONFIG:CW WGHT menu entry and tap '4', changing VOX NOR to AUTO OFF. This will make CW VOX default to OFF when the K3 is turned on. That way, if a person accidentally forgets to turn VOX OFF when he shuts the radio down, it will automatically turn itself OFF next time you turn the K3 on. On my radio, if I want to transmit after I turn the radio ON, I have to re-select VOX ON again.>>> This does not solve or change the problem. The problem is, when the radio boots up, the amplifier relay control line is pulled low during the very early part of the power up. This happens in any mode with any VOX setting. The situation this creates is if an external power amp with step-start is connected, some amplifiers go into quiescent current (TX relay closure) when the radio is powering up. This false triggering of the PA relay can cause an amplifier inrush circuit to be damaged. For example the Drake L4B would would try to draw about 500 additional watts through the step-start if the TX line was held low on amplifier power up if the radio is booting at the same time. Seeing all my TX indicators illuminate and hearing relays click when I power up the K3 is more of an annoyance to me, because my amplifers are designed to be in any keying state on power up without damage. On some amplifiers though, it can actually hurt components if they are held in TX mode while powering up. I think the burden of design fault is in the amplifier, there should be no relay line state that causes or allows damage on power up, but the radio boot behavior is a little annoying. It might be some I/O areas like the relay control just fault into a TX mode before the system is booted, and there may be no way around that. 73 Tom ______________________________________________________________ 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
