[Elecraft] K3 FSK External Pullup

[Clint Hurd]

Is an External Pullup resistor needed on the FSK (ACC pin 1) input line? 
One of our Navigator Interface users reported that if the FSK line is also 
tied to an external pullup resistor, that it  caused his K3 to refuse to 
stay powered up when the cable was connected.  He subsequently removed the 
pullup and the system operated normall.

The pullup resistor is a 4.7K through a diode to +5V.  Our original cables 
for the K3 were wired with this pullup connected, and no problems have been 
reported until now.  We will remove the pullup connection from our drawing 
since it is not needed, and all future cables will not have this connection.

Has there been a change in the K3 that would cause this problem?  If so, if 
earler users upgrade their units to lastest specs, will they also have this 
problem?

Clint
KK7UQ