[DSP-10] probems in TX and RX - DSP-10 with KK7

[Francisco Augusto]

hi mr. bob larkin and everybody,

I'm a undergraduated student of eletrical engeneering from Brazil, and I'm
trying to assemble the DSP-10 kit with KK7 DSPX module.

I've started it a year ago, but it still doesn't work.

I've been fighting agaist many problems. I can list some of them. But
first of all I would like to explore a possible mistake in the
project.

+10T and +10R are always high (10V), for any bit value in shift
register. I've even bought new transistor (Q106 and Q105) and tested
them separately, but in the board it does not work. the voltage in the
gate of Q105 and Q106 are low at 0.04V and High at 9.98V. The switch
from the bipolar transitor is ok and the diode is ok too. It seens
that the FET transistor (Q105 and Q106) are switching at a very low
voltage.

Then, I've changed it to a bipolar one wHich works well, but it is not
allowed to suply a high current needed to the circuit ahead. Does
anybody else have had this problem? does anybody knows anothe FET
transistor with a higher voltage theshold? thanks a lot for your time

Francisco Augusto Garcia
SDR Group