19" Rack Mount Height

I'm building the casing for the Fairchild 670. Would anyone know if it is exactly 14" high as the official manual states? I read somewhere that the sum for working out 19" rack unit height is:

h=(1.750n - 0.031)

N is the number of units. if the FC670 does indeed take up 6u of rack space then its actual height would be 10.469 inches. Am I cocking this up somewhere? Or is the FC670 an 8u beast, making its actual height 13.969?

Any input would be appreciated!

The 670 was not in 19" format iirc

to get into a standard rack, you sub-mount it:




Jakob E.

http://en.wikipedia.org/wiki/19-inch_rack

EIA rack standard

JR

gyraf said:

The 670 was not in 19" format iirc

to get into a standard rack, you sub-mount it:

Jakob E.

Click to expand...

Thanks for getting back to me. Just to clarify you're saying that the 14" stated in the manual is correct? Are most units made in this era in need of 'sub-mounting' to fit into contemporary 19" rack units?

670s were in fact 19" rack mountable. The picture above shows how it was done. The grey part is the steel chassis that is 14" tall. The face panel is 8 3/8" tall and and 16" wide. Not shown is the lower face panel that exposes the controls for HV and DC threshold.

marc11657 said:

I read somewhere that the sum for working out 19" rack unit height is:

h=(1.750n - 0.031)

Click to expand...

As JR posted, RU heights are 1.75, 3.5, 5.25, 7"... but the units that are meant to be mounted need some functional play.
I don't believe there's a norm for it because it depends on the construction techniques used, in particular the general manufacturing tolerance, the existence of mounting srews on the lid and the type of finish - paint thickness is difficult to control.
You may see that the country of manufacturing has some consequence. In particular 1U units from metric countries are very often rounded to 44mm instead of 44.45.

If there was a norm for it, no-one told Eventide.  The original H910 Harmonizer had a power transistor mounted on the exterior of the left side of the case and it wouldn't fit into a standard rack

That's why you'll find most studio racks have a 3/4" x 1/4" section filed out on the left hand side somewhere to get the Harmonizer in and out of the rack..

Nick Froome

pvision said:

If there was a norm for it, no-one told Eventide.  The original H910 Harmonizer had a power transistor mounted on the exterior of the left side of the case and it wouldn't fit into a standard rack

That's why you'll find most studio racks have a 3/4" x 1/4" section filed out on the left hand side somewhere to get the Harmonizer in and out of the rack..

Nick Froome

Click to expand...

Interesting! IIRC there is a norm that defines the max width of the unit after the front panel at 17".

Some older AMS units were WIDER than 19" at the face plate. (ask me how I know, some time!)

Eventide H949s had TO3 regulators on the right hand side of the case which used to catch on UK/Europe cage-nut rack frames... but Eventide likely never realized this because the US generally tends to used threaded rack rails, which are significantly narrower, allowing 949's to pass through far more easily.

Some older BEL products (BF20, I think was one) used to be TALLER than the regulation 3.5" height for 2U.

There was indeed a 17" max. width in the specifications. -Eventide either forgot, or never read that far.