[R-390] Rack Mounted R-390A

[Tom Norris]

The reference is on page 5 of TM 11-5820-357-20 manual in the  
installation section, it says --

"Caution: When the receiver is installed in any cabinet other than  
described above, adequate ventilation must be provided. For mobile  
applications of the receiver in cabinets other than Cabinets,  
Electrical Equipment CY-979/URR and CY-1216/U, support must be  
provided at the rear of the receiver, so that the front panel does  
not carry the entire weight of the receiver."

Similar info for the 390A is found in paragraph 6 section 6 of AFTO  
31R1-2URR-422/TM 11-5820-358-20  (page 10 of feb '61 printing)

But since folks argue with the manuals about things like solid state  
rectifiers being wrong, I guess they won't agree with this either.    
If the shafts bind, it may be as simple as adjusting the front panel  
bushings.

I'd rather use the angles that try to wrestle with an 85 pound radio  
at shoulder height with one hand while removing screws with another  
and keeping it from destroying what's below it in the rack with a  
third hand.  I've not sprouted that third hand though, no matter how  
many vitamins I take, so I use the anglestock.  Slide it in, secure  
the front.  No trying to support it while fastening it to the rack.

Tom

On Feb 6, 2006, at 8:53 AM, Todd, KA1KAQ wrote:

> Hey Tom -
>
> Mounting by the front panel alone might work, but it can and does
> cause torque/flexing issues that can cause the PTO to bind up or
> become stiffer to tune. I have an old AF rack for these beasts with
> the angle 'shelf' pieces built right in and the correct intervals. It
> almost seems like there are references in some TM not to mount by
> panel alone with no rear support, but I can't recall.
>
> de Todd/'Boomer'  KA1KAQ
>
> On 2/5/06, Tom Norris <r390a at bellsouth.net> wrote:
>
>> Hank is correct, but it makes a whole heck of a lot easier to get in
>> and out of the rack if you put in those angle bits.  HP supplied
>> those sort of angle "shelves" in some of their larger equipment
>> system racks for just that reason. (I think it was HP...)
>>
>> Tom
>>
>>
>> On Feb 5, 2006, at 6:15 AM, Dan Arney wrote:
>>
>>
>>> 1000's of them have been mounted by the front panel only with no
>>> problems.
>>>
>>> Hank
>>> KN6DI