In my research on the avionics of the FIAT G91R I finally found the model of doppler radar used on board the aircraft. It was the Bendix DRA-12, a Doppler navigation radar which allowed an accuracy of 0.5%. The article, which I have added to the cover, was extracted from Flying Magazine June 1963 Page 32.
The article is available in complete form at the following link (go to page 32)
http://books.google.it/books?id=GUSqNw60iJkC&lpg=PA32&ots=GWKpbf63SH&dq=Bendix%20dra%2012a%20doppler%20manual&hl=it&pg=PP1#v=onepage&q=Bendix%20dra%2012a%20doppler%20manual&f=falseThis is a picture of the control panel Bendix doppler, mounted on the G91:
This is a picture of the computer Bendix CPA-24 mounted on various passenger aircraft, primarily for transatlantic routes:
The manual Bendix DRA-12 is unfortunately only on ebay, it would be helpful if someone could find and send it in digital format!I would like to create a simulation of the system DRA-12, and together with electromechanical computer PHI Mk3 (of which I only found the manual MK2). Bendix at the time (around 1963) made also the computer (transistorized) CPA-24 often mounted on the 707 (later also on the early 747) or the DC8 for the Atlantic routes.
I always hope that some lovers of avionics can help me, I think it is very interesting to use these tools to complete the magnificent 707, the G91 and other aircraft that have used the Doppler navigation systems.
There is to be noted that these instruments were, for the time (1960-1970), really excellent. The precision allowed to make a transatlantic flight with a precision of 0.5% at a cost of $ 16,000 + 11,000 (if one adds the spare drive). In 1960 26.000 $ was the price of a small plane!