Also, if the electrical AF/RF knob swap is done, the slightly longer inner knob on the Sub AF control makes its use as a fader between Main AF and Sub AF a dream to use. Details below.
Paul, W9AC > 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" <w...@arrl.net> > To: <elecraft@mailman.qth.net> > 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 function >> menu is selected for "Normal," rather than AF "Balance," a similar issue >> can >> arise 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://72.52.250.47/images/K3-AF-1.jpg >> >> And the "after" wiring... >> >> http://72.52.250.47/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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
