[Elecraft] K3 Power Supply Question

[James Bennett]

Folks - thanks for all the input. I think I may have found one of the culprits in the system - oxidation. I put everything back together the way it was to begin with so I could switch back and forth between the K3 and KX3 power displays. I have a KXPA100 behind the KX3 so the load on the MFJ 4245 should be about the same with either one transmitting 100 watts and the other one receiving. What I see now is 13.9 volts on receive and 13.0 - 13.1 during transmit. Waayyyyy better than the drop to 12.0 I saw yesterday! 

I might get ambitious and “upgrade” the cables from #12 to #10 and ensure that the APP contacts used are the 30 or 45 amp versions. Will also look into a re-design of the Boost Regulator’s position in the power system. RIght now it supplies boosted power to the Rig Runner. I think it’ll be an easy matter to swap some cabling around and have the output of the Power Gate go to the Rig Runner and have the Boost Regulator tie into the Rig Runner, delivering it’s output directly to the KX3, K3, and KXPA100. I believe this is one of the suggestions made by W3FPR. I’m pretty sure my desk lamp and the PX3 won’t mind only having 12.8 v instead of 13.9! :-)

73, Jim

Jim Bennett / W6JHB
Folsom, CA