I set some time aside this weekend to install a second receiver in my K3, and to perform the 12VDC Out Current Modification since I was adding a SVGA card to my P3 (which requires more current than the stock 0.5 Amp output). My comments pertain to the latter.
Elecraft provides the modification kit with the SVGA card and it is very easy in concept, requiring the removal of one SMT diode, and two thru-hole components (a poly-fuse and a choke). The bulk of the time involved is strictly mechanical -- removing covers and sub assemblies to provide clean access to the parts. It was the mechanical aspect that immediately bit me in the backside. My K3 had been lovingly brought to life by the Elecraft factory this January. The first step to the modification is to remove the rear half of the bottom cover. Easy enough, remove 10 screws. The instruction warns you that three of the screws are part of a heat sink assembly which just requires taking care to not lose the washers and other parts attaching the LPA power transistors. However three of the other screws attach to standoffs that are fastened to the main PCB. In my case, unscrewing two of the black pan head screws on the bottom actually caused the hardware attaching the standoffs to unscrew instead, dropping two screws and washer inside the radio. Full stop -- the last thing I wanted to do was flip the radio over and lose those loose parts. So I got eyes on the the loose parts first (as I already had the top cover off for the Aux Receiver install). To avoid this, I would recommend taking the Top Cover off first, then using a screwdriver to tighten down the two screws that are holding the standoffs to the aluminum L-bracket that holds the PA. Then I would remove the fan assembly and PA assembly and tighten the third screw. The LAST thing I would do is remove the bottom cover -- while making sure that the L-bracket screws don't come out (this is the FIRST step in the instruction). My only other observations is use of a good solder sucker (one with high vacuum) is probably helpful for removal of the two leaded components -- otherwise cutting the component body off and removing the leads while heating them might be a good strategy if solder braid is the only available option to remove the remaining solder. The modification would have taken about 30 minutes had the standoffs not come off at the wrong time, and the rework is easy if you have a decent solder sucker. 73, Bob, WB4SON. ______________________________________________________________ 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
