I looked into this for my own Argosy (525) not long ago after
discovering the '86 HR article and discovered that my rig (no. 201)
didn't use discrete diodes. TT had modified the board to use an IC
mixer. Many of the other changes listed also had been made, either by
the factory or by the original owner.
For those that have discrete diodes, make sure that TT hasn't already
made the change to the HP diodes (my schematic/parts listing refers to
special 2800 diodes but uses the mixer IC). Allied Electronics has the
(both the Schottky and the PIN diodes listed in the article) but they
have a $50 minimum order.
73 de N9WR, Don C. Faith III
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