Yes I´m beginning to think that K3 is more sensitive to PS then other radios, right now it looks that way. Then this should be in the manual!!! What happens is if I have a bad signal on the bands I will together with Elecraft get a bad reputation. I will of course tell everyone what I´m running and do have it operating exactly according to the manual.
If this PS deal is the case with the K3 I quite understand and it´s no problem to me what so ever but it should be in the operating manual. Every user of a K3 should not need to be a super engineer and have to figure out things like this them self. This morning I increased PS voltage to 14.6V (14.2) under load, I was at 13.9V (13.5 load) before, I could see a "slight" improvement in IMD (1-2 dB). I am using the supplied high performance cable from Elecraft and IMO it does not have enough Cu area. Next But if Elecraft supplies it and it´s not good enough, what can I say? / Jim SM2EKM ------------------ AD6XY wrote: > 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 > > _______________________________________________ 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
