[R-390] Ebay Auction

[Robert Nickels]

ToddRoberts2001 at aol.com wrote:
>  I was only commenting that it is not good practice to stack the 2 
> radios close together like that if someone got the idea it is OK to do 
> that from the picture.    
Well...it really *is* OK to do that.  The "bible" aka TM 11-856A 
describes installation of the R-390A/URR in the following cabinets:

Cabinet, lightweight, tabletop CY-917/URR
Cabinet, med. duty, floor mount CY-1119/U
Cabinet, mobile mount, CY-979/URR
Cabinet, mobile mount, CY-1216/U

The CY-1119/U cabinet is a 76" rack that is part of FRR-33, FRR-34, 
FRR-38, FRR-39, FRR-40, FRR-41 - each of which includes 2 or 3 R-390A 
receivers mounted in a similar fashion.   What does the "bible" say 
about how to do this?

Para. 14b (2):  "To install the receiver in a standard cabinet such as 
Electrical Equipment Cabinet CY-1119/U, remove the top and bottom dust 
covers from the receiver".

Later, in the section on ventilation:  "In all types of installations, 
allows as much ventilation as possible.  Do not operate the receiver 
with dust covers in place unless extremely dusty or sandy conditions 
exist.    And:  "In fixed installations, operate the receiver with the 
tube shields removed (para. 13e).  This will reduce the bulb temperature 
of the tubes and will prolong tube life.   Whenever possible, allow 
space at the back of the cabinet or rack for circulation of air".
That's what I've done with my stacked R-389, R-390, and R-390A - with no 
problem.    In short, it's the dust covers and tube shields that we 
should pay attention to, not vertical installation in a rack.  Yet how 
many R-390A owners have bought replacement dust covers and IERC tube 
shields "to restore authenticity"?

73, Bob W9RAN