[R-390] Ebay Auction

[Barry Williams]

I don't have the list right here in front of me, but some of the tubes 
require the covers. I have a copy of a report that we all saw some years 
back where the true IERC tube shields prolonged tube life.


Barry
>
> 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
> _____________________________________________________________