[R-390] R390A contractors and numbers of units

[wb3fau at att.net]

Heres some general questions for users of these receivers.  How  many units were built?  Did they also sell separate subchassis to the  gov't?  The original  design  was by Collins,  but later, 
they let other builders bid on the contracts?  Were the contracts awarded  by lowest  bid?  Does anyone know  how much one cost?  I  understand there were  about 12 different contractors?
Are there  still any new  unused units- in storage hidden away   by different gov't agencys? 
  I  have other  questions,  but  this  ought to be plenty to get  this group humming along.
Russ-WB3FAU.