[R-390] Rack Mounted R-390A

[w9ya at arrl.net]

Hey Tom and the gang;

I agree....

It is common practice to add support for heavy items placed in racks. I
see this in the racks at work for equipment weighting in at less than the
r390 series. We have over 100 racks worth of equipment there. I have seen
this additional support used at other places I have worked at or been
associated with. You can buy these rear and side angles from the rack
manufacturers directly or several other palces if you would rather not
make these yourself.

I also regularly see bent equipment that does not have additional support.
I repair the electronics that sit in these racks as my primary function at
work. I have been doing this repair work for over 35 years. I do not see
bent equipment that has had additional support added.

Sometimes we add support that the manufacturers did not otherwise
recommend. It does not hurt to do so. The equipment seems to be easier to
move around and stays square when we use additional support for heavy
equipment we mount into these racks.. This is NOT rocket science,
(although we do some similar things at work,) but rather a matter of
common sense.

SO.....IMnsHO, if we would like our older equipment to last a bit longer
and be easier to move into and out of the racks; perhaps we should
consider doing some things hinted at in the manuals and from our direct
experience that will keep them cool and square


Vy 73;

Bob
w9ya


> 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
>
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