[amsat-bb] Re: Ft-847

[Alan P. Biddle]

Don,

If I understand correctly, when you hook either of the mics up in the normal
fashion, you get no PTT(?), or frequency control, but it works normally
through the Rigblaster?  Strange, as I have both those mics, and they work
as expected with the FT-847.

The fact that you can work normally in all respects(?) though the Rigblaster
indicates that the internal FT-847 wiring is probably ok except for the
possibility of the control ground.  It is on pin 5.  This is really
reaching, but is there any chance that the control ground is blown?  You can
check with a VOM.  (A spare 8 pin mic plug is a good way to do this, and
tends to reduce the likelihood of accidentally shorting a pin, especially
the +5 volts on pin 2 which will blow the series resistor at only 100 ma.)
These digital interfaces are often pretty cavalier about separating out the
two grounds, and the Rigblaster may be providing the needed ground by
combining the two.  The schematic, or some quality time with the interface
and VOM can answer this.

Probably wrong, but it is at least consistent with the symptoms as I
understand them.

Alan
WA4SCA