Hi,

If I could build a high quality rf-tight small enclosure for dc-30 Mhz
at low to moderate cost, what would you need?

Thanks,

The Eternal Squire

wrote:
Hi,

If I could build a high quality rf-tight small enclosure for dc-30 Mhz
at low to moderate cost, what would you need?

They already have them at the grocery store. They must be for us
homebrewers, because they even come with these useful breath mints too.

More seriously, what have you got that isn't a minibox or a die-cast
box or a chassis box or a desktop enclosure?

Tim.

ORIGINAL MESSAGE:

wrote:

Hi,

If I could build a high quality rf-tight small enclosure for dc-30 Mhz
at low to moderate cost, what would you need?

Thanks,

The Eternal Squire



*********** REPLY SEPARATOR ***********

I use the Pomona die-cast boxes, but they are expensive. If you can
improve the cost factor, I will beat a path to your doorstep, as will
others.

Bill, W6WRT

Bill Turner wrote:
I use the Pomona die-cast boxes, but they are expensive. If you can
improve the cost factor, I will beat a path to your doorstep, as will
others.

The Pomona die-cast boxes with card mounting slots and prefabbed for
BNC's are the glitz, man. (And it's not easy to die-cast all that stuff
on, probably explains why even the little boxes can cost $70.)

Bud/Hammond/etc. make much less glitzy die-cast boxes for a lot less $.

Maybe our eternal squire wants to use CNC machines to make boxes out of
aluminum ingot? :-). Take the scraps, melt them down, repeat!

Tim.

I find that boxes are generally too expensive, and rarely the right size.

Generally, I want a box for the desk, so it typically could stand to be
fairly deep -- say 7-10 inches. I also want it wide enough for a few
controls and an LCD, so maybe again, 7-10 inches. The height generally
seems to be the problem. It seems like boxes are either an inch and a half
high, so you can't get a display in there, or 5 inches, way taller than
necessary. I would think that 2.5-3" high boxes would be awfully handy, but
they seem rare.

And of course, they tend to be horribly expensive.

Card guides inside would be nice.

Aluminum would be nice so that it is easy to machine. Although in reality,
some sort of lined plastic might be better.

Thick enough to be strong, but thin enough that it doesn't weigh a ton --
plus, a thick panel looks junky in front of a display.

Powder coated would be nice, but at least some reasonably clean finish so I
don't have a ton of work to do before painting.

I often use plastic boxes with a removeable, flat panel. I can replace the
panel with plexiglas, so that instead of trying to make a square hole for
the display, I can simply mask off a square hole. As an added bonus, my
labels are protected by the plexi. Unfortunately, these kinds of boxes
aren't RF tight. In an ideal world, I would have that sort of box, sprayed
on the inside with RF proof paint, and with an insert I could place behind
the display to make the front RF tight too, while still allowing for the
display. Pipe dreams I guess.

...

wrote in message
ups.com...
Hi,

If I could build a high quality rf-tight small enclosure for dc-30 Mhz
at low to moderate cost, what would you need?

Thanks,

The Eternal Squire

i usually use unethed doublesided pcb and solder it together.

"xpyttl" schreef in bericht
...
I find that boxes are generally too expensive, and rarely the right size.

Generally, I want a box for the desk, so it typically could stand to be
fairly deep -- say 7-10 inches. I also want it wide enough for a few
controls and an LCD, so maybe again, 7-10 inches. The height generally
seems to be the problem. It seems like boxes are either an inch and a
half
high, so you can't get a display in there, or 5 inches, way taller than
necessary. I would think that 2.5-3" high boxes would be awfully handy,
but
they seem rare.

And of course, they tend to be horribly expensive.

Card guides inside would be nice.

Aluminum would be nice so that it is easy to machine. Although in
reality,
some sort of lined plastic might be better.

Thick enough to be strong, but thin enough that it doesn't weigh a ton --
plus, a thick panel looks junky in front of a display.

Powder coated would be nice, but at least some reasonably clean finish so
I
don't have a ton of work to do before painting.

I often use plastic boxes with a removeable, flat panel. I can replace
the
panel with plexiglas, so that instead of trying to make a square hole for
the display, I can simply mask off a square hole. As an added bonus, my
labels are protected by the plexi. Unfortunately, these kinds of boxes
aren't RF tight. In an ideal world, I would have that sort of box,
sprayed
on the inside with RF proof paint, and with an insert I could place behind
the display to make the front RF tight too, while still allowing for the
display. Pipe dreams I guess.

..

wrote in message
ups.com...
Hi,

If I could build a high quality rf-tight small enclosure for dc-30 Mhz
at low to moderate cost, what would you need?

Thanks,

The Eternal Squire

Tim Shoppa wrote:
Bill Turner wrote:
I use the Pomona die-cast boxes, but they are expensive. If you can
improve the cost factor, I will beat a path to your doorstep, as will
others.

The Pomona die-cast boxes with card mounting slots and prefabbed for
BNC's are the glitz, man. (And it's not easy to die-cast all that stuff
on, probably explains why even the little boxes can cost $70.)

Bud/Hammond/etc. make much less glitzy die-cast boxes for a lot less $.

Maybe our eternal squire wants to use CNC machines to make boxes out of
aluminum ingot? :-). Take the scraps, melt them down, repeat!

Tim.

Got it in one guess! That, or you've been reading more newsgroups
than homebrewers.
I'll be happy for specs.

The Eternal Squire

wrote:
Tim Shoppa wrote:
Maybe our eternal squire wants to use CNC machines to make boxes out of
aluminum ingot? :-). Take the scraps, melt them down, repeat!

Got it in one guess! That, or you've been reading more newsgroups
than homebrewers.
I'll be happy for specs.

Look at how, for example http://www.pcbexpress.com/ and
http://www.frontpanelexpress.com/ do business. I could imagine a
business model not too different working for custom-machined enclosures
(and CNC'ed metal widgets in general.) Target audience would be
engineering firms that don't do this in-house and aren't set up with a
local vendor, hobbyists, etc. Maybe some customers that don't do this
at all yet (amateur jewelers? who knows!!!!?!!!)

One thing that those outfits have is free CAD software for
design/specifying. If you kept your options really straightforward
(e.g. boxes with round holes and square holes for example) maybe design
could be done over the web. (Dynamic graphic generation, or maybe SVG
with user interface.)

Tim.

wrote:
On 14 Mar 2006 23:08:41 -0800, wrote:

Hi,

If I could build a high quality rf-tight small enclosure for dc-30 Mhz
at low to moderate cost, what would you need?

Thanks,

The Eternal Squire

I have plenty of diecast and Other aluminum boxes from various
vendors. The usual problems are finding them and cos t(even
aluminum miniboxes are costly for the metal sheet in them).

Often a project will require several of differing sizes so I may make
internal shield boxes box using single or two sided copper clad
board (scrap). Cheap, solderable, good shielding.

Whem I want something that looks good Hammond, LMB and TenTec
offer very stylish boxes.

Allison


Thank you all,

The Eternal Squire

Tim,

After studying this, I have a question:

It seems to me that I should basically have a standard design with
options. I could then post the drawings as a webpage for people to
look at and specify those options. It will be a while before I can
consider making one-of-a-kinds for people, but standard specs and
stackable configurations I could do on a JIT basis.

Would that be acceptable for now until I could afford greater
sophistication?

Thanks,

The Eternal Squire


Tim Shoppa wrote:
wrote:
Tim Shoppa wrote:
Maybe our eternal squire wants to use CNC machines to make boxes out of
aluminum ingot? :-). Take the scraps, melt them down, repeat!

Got it in one guess! That, or you've been reading more newsgroups
than homebrewers.
I'll be happy for specs.

Look at how, for example http://www.pcbexpress.com/ and
http://www.frontpanelexpress.com/ do business. I could imagine a
business model not too different working for custom-machined enclosures
(and CNC'ed metal widgets in general.) Target audience would be
engineering firms that don't do this in-house and aren't set up with a
local vendor, hobbyists, etc. Maybe some customers that don't do this
at all yet (amateur jewelers? who knows!!!!?!!!)

One thing that those outfits have is free CAD software for
design/specifying. If you kept your options really straightforward
(e.g. boxes with round holes and square holes for example) maybe design
could be done over the web. (Dynamic graphic generation, or maybe SVG
with user interface.)

Tim.