[ETO_Alpha] Alpha 89 Question

[Robert Dorchuck W6VY]

Hello All,
I have the opportunity to purchase a Alpha 89 and have a couple of questions.
How reliable are the pin diodes?  
In looking at the schematic it appears that 7 pin diodes are used D1 & D2
(MA4P4006) and D9-D13 (KS1001).  Are these available and at what cost?
 
Any other recurring problems with the 89 that one should be aware of?
 
How would you compare the 89 with the 78?
 
Thanks,
Bob  W6VY