BTW, the mod is likely possible with a future F/W change to allow changes just as the current menu allows for 'Normal" and 'Balance' audio functions. If that ever happens, the wiring mod is very easily reversible in less than a minute with no evidence left behind.
Paul, W9AC ----- Original Message ----- From: "Paul Christensen" <[email protected]> To: <[email protected]> Sent: Thursday, September 10, 2009 12:27 PM Subject: [Elecraft] K3 AF/RF Mod > Okay, I couldn't leave well enough alone... > > Yesterday morning, I was working a T30 station split on 40m with the K3's > Sub Rx and became a bit unnerved with the manipulation of the K3's "Sub > AF" > control when balancing between Main and Sub receivers. Multiple quick > reaches for the "balance" function on the upper Sub AF control's outer > ring > was causing me to accidentally come in contact with the other controls. > Looking at the K3 schematic, all four controls (Main AF, Sub AF, Main RF, > and Sub RF) are all 10K in value. Even when the K3's AF control furnction > menu is selected for "Normal," rather than AF "Balance," a similar issue > can > arrise when trying to quickly balance the Main/Sub AF controls on one > shaft. > > I removed the front panel to inspect the Front Panel PCB and thought a > swap > of the Sub AF and Main RF controls could be easily accomplished. Here's a > "before" photo of the PCB area: > > http://216.229.20.37/images/K3-AF-1.jpg > > And the "after" wiring... > > http://216.229.20.37/images/K3-AF-2.jpg > > A hot glue gun can be used near the 5-pin header to keep the two ribbon > cables from interfering with future front panel extractions and > insertions. > Now, the upper controls handles Main AF (inner) + Main RF/SQL (outer). > The > lower controls handle Sub AF/Balance (inner) and Sub RF (outer). > > When I engage split operations and use the Sub Rx, manipulating the > balance > between Main AF and Sub RF is easier with a bit less propensity to > accidentally come in contact with the adjacent controls since: (1) the > Main/Sub AF balance function is now on the inner concentric control and > extends out further from the front panel than the outer concentric ring; > and > (2) the balance function is now moved to the bottom where the hand can > approach the control from the bottom rather than directly in-line with the > knob. > > If needed later for a sale, reversal of the mod is very easy. Certainly, > this mod is not for everyone. However, I would think that in later PCB > revisions, Elecraft could provide the option of selecting the existing > format or the modified format at the time of purchase -- or to the builder > who simply makes a few header pin changes during construction. > > Of course, the front panel legends also need changing and that's probably > the biggest drawback to the mod. In my case, I will use new legends > printed > from a Brother 'P-Touch' printer -- printed with white lettering against > black background tape. Font size and type is adjustable to match the > existing legends on the K3. > > Paul, W9AC > > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
