On Friday, December 5, 2014 6:25:35 PM UTC-8, wrote:
Bumper: could you send me the MKIV calibrated for the Southern Hemisphere? Really don't want it indicating a slip when I'm really skidding;-)

Of course you can send your MKIV in for a complete calibration for only $15.. This includes, gps battery replacement, internal clock reset, resealing, and testing in our wind tunnel to assure compliance with all applicable standards. As a service to our existing customers, a reboot can also be done in the field as explained below.


True, the MKIV, though rugged, is sensitive and will naturally take a "set" when used for long periods of time on just one side of the equator. This set is due to the polarity of the E-field and H-field and back as$ward Coriolis effect down there (or up there if you're already down there).

Note to Jim Payne: Don't worry about any of this until you head back "up there", I took the liberty pre-calibrating your MKIV's for down there in Argentina.

While it is possible to weaken the offending backwards fields by turning off the master switch, a more positive and entertaining method of rebooting the MKIV is to momentarily reverse polarity of your avionics battery connector (don't be alarmed, some sparking and a little smoke is acceptable and a good sign your battery is not dead). Note that the principle behind this fix is similar to turning off the master switch, only more positive and, um, "permanent". After this reboot, you may find your trusty MKIV is one of the few remaining instruments in your ship that still functions properly . . . a glowing testament to how truly rugged the MKIV is.

bumper