  Proximity effects and pair currents were measured in epitaxial trilayer
\textit{c-axis} junctions comprise of a $PrBa_2Cu_3O_{7-\delta}$ barrier
sandwiched in between an overdoped $Y_{0.94}Ca_{0.06}Ba_2Cu_3O_{7-\delta}$ and
underdoped $YBa_2Cu_{2.7}Co_{0.3}O_y$ layers. These junctions had two $\rm T_c$
values of $\rm T_c(high)=84-86$ K and $\rm T_c(low)=50-55$ K, allowing
investigation when both electrodes are superconducting, or when only one is
superconducting while the other is in its pseudogap regime. For T below $\rm
T_c(high)$ but much above $\rm T_c(low)$, two distinct proximity effect
transitions were observed in the resistance at two temperature regimes, between
80 and 84 K, and 76 to 80 K. The first is a conventional proximity effect with
the $\rm T_c(high)$ electrode, while the second is a second-order proximity
effect of this electrode with uncorrelated pairs in the pseudogap regime.
Conductance spectra measured between 2 and 86 K showed four different $I_c$
pair currents which were attributed to coherent pairs tunneling through the
barrier below 42 K, to fluctuating pairs current up to $\sim$77 K, and to
proximity pairs current between 77 and 84 K. All pair currents were suppressed
under magnetic fields, with two distinct decay parameters that originated in
the two different electrodes, with a significant suppression observed in the
pseudogap regime.
