Everyone knows it is important for the K3/100 to receive a solid DC supply.
If the supply drops significantly when high current is drawn several effects may occur: 1 - The Transmitted signal becomes wider than it should be 2 - The power control loop is upset leading to unstable output power 3 - In severe cases the radio might shut down, or engage sulk mode. Of course this does not apply to us, we are all experienced constructors and never make mistakes when wiring up our shacks. Like many people I run my K3 from a 13.8V DC supply that also supplies other items, in my case XV transverters, an LP100, an LDG ATU etc. This supply is very good (tnx BNOS, 1980s) and only varies by a few 10s of mV between no and full load. Originally when installing my K3/10 I used the supplied DC cable via a powerpole distribution board with an appropriate fuse. In fact this particular board had two fuses, one 30A one at the input and one at the output plus around 1 metre of thick cable to the supply. This worked fine. Later I upgraded to the 100W KPA3, and of course changed the fuse in the distribution board. The DC voltage drop according to the K3 at 20A was over a volt, much no doubt due to the fuses and extra connections through the distribution board. A 1 volt drop is not a problem for the K3 but will cause more IMDs on SSB. I now connect the K3 directly to the PSU with as short a DC cable as is practical. It would be even better to use voltage sensing so the supply is regulated at the K3 end of the cable. Mike -- View this message in context: http://n2.nabble.com/K3-100-and-the-PSU-tp2223048p2223048.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ 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
