开云体育

The posting to the list about not having an enclosure on a rig and what
can happen is the reason that I learned to make my own. Too many projects
to buy enclosures that cost almost the price of the project in many cases.

So let me show you my latest enclosure for the 5W20A S/N 001 from
kitsandparts.com and the A added to the name is for Arnold because it
is a 1W on steroids. :-)

The first photograph (...09.jpg) is the enclosure with one coat of
Rustoleum primer
self etching from Home Depot paint department followed by one coat of
color.
I was in a hurry to get the document done. I have never seen self
etching primer at
Wal*Mart and haven't looked at Ace.

Bottom is painted white with one coat of an old can of generic Wal*Mart.
Top is painted with one coat of Rustoleum Candy Apple Red (2X label
for primer plus paint). Now this has got to be the closest to fire
engine red that I have found and this is my first use of it and it won't
be my
last. I love the bright color. Hope the photo and your monitor does it
justice..

Second photo (...12.jpg) is the innards of the rig. Couple of points.
Note the 'floor' mounting of the display. I had some boards made up
at JLCPCB so that I could use the Keystone 621 right angle brackets from
Mouser for mounting and not have to put four holes in the front panel.
It is the QRPGuys circuit and parts. My board layout as I set the kit
board aside for this project.

Also the 12mm x 20mm aluminum plates expoxied to the two PA transistors.
I found that a key down of 10 seconds without the heat sinks drove the
temperature to over 48 deg C (120 deg F for those that refuse otherwise).
With the heat sinks the temperature only went to 29 deg C. Since I did
this transceiver with my parts and we hadn't come up with the kit heat
sinks, I tried the above in a pinch. If I can find the heat shrink
container, I'll try the kit setup and report in the document when I
release it.

The reason people use Al over Cu is that Al has twice the heat transfer
rate.

Third photo (...13.jpg) is the cover on. I got the dimensions within
0.1mm for this case. I need to work on the display nibbling, but will
3D print a border for it to hide the tool marks.

Yes, there are dust marks. It was windy here at the time and I could
not get the parts from outside to the oven before some dust hit the
wet paint. I may touch up later, but then it's going on the desk and
on the air.

Cost of enclosure was about $2 USD worth of Al. The joy: priceless.

I try to keep unenclosed rigs away from the workbench when cutting is
in progress.

FYI

chuck, k7qo

Chuck!

What thickness of Al did you use? I take it you have a bending brake of
some sort?

73! Mark KA6WKE

Thanks for the quick response Chuck. Not sure where this lab notebook has
been all my life! It has a section on making enclosures out of PCB but
didn't see anything about Al enclosures. I'll check out Youtube when I have
time.

73! Mark KA6WKE

Website:
Live Stream:
YouTube Live!:
Author: 4NEC2 The Definitive Guide EMail List:: [email protected]


On Thu, Jun 27, 2019 at 6:40 PM chuck adams <chuck.adams.k7qo@...>
wrote:

I use 0.040" Al. I have section in the lab book and in some youtube
videos under K7QO.

I use a cheap Harbor Freight brake, also documented in both of the
above so that I don't want to take up much room here.

FYI

chuck, k7qo

On 6/27/19 4:26 PM, Mark Schoonover wrote:

Chuck!

What thickness of Al did you use? I take it you have a bending brake of
some sort?

73! Mark KA6WKE

Mark,

You're right. I did not write it up in the lab notebook

and that is my fault. I thought of it. I thought it through. Just
didn't type it
in.

And, just for reminding me of that fact that it should be in the book, I
will spend
tomorrow doing one for a 1W. Your call. You want it with a digital
display or do
you want one with an audio frequency readout. Can't have both in one
day. :-)

You choose.

chuck, k7qo


On 6/27/19 6:59 PM, Mark Schoonover wrote:

Thanks for the quick response Chuck. Not sure where this lab notebook has
been all my life! It has a section on making enclosures out of PCB but
didn't see anything about Al enclosures. I'll check out Youtube when I have
time.

73! Mark KA6WKE

Website:
Live Stream:
YouTube Live!:
Author: 4NEC2 The Definitive Guide EMail List:: [email protected]


On Thu, Jun 27, 2019 at 6:40 PM chuck adams <chuck.adams.k7qo@...>
wrote:

I use 0.040" Al. I have section in the lab book and in some youtube
videos under K7QO.

I use a cheap Harbor Freight brake, also documented in both of the
above so that I don't want to take up much room here.

FYI

chuck, k7qo

On 6/27/19 4:26 PM, Mark Schoonover wrote:

Chuck!

What thickness of Al did you use? I take it you have a bending brake of
some sort?

73! Mark KA6WKE

I use 0.040" Al.? I have section in the lab book and in some youtube
videos under K7QO.
I use a cheap Harbor Freight brake, also documented in both of the
above so that I don't want to take up much room here.
FYI
chuck, k7qo
On 6/27/19 4:26 PM, Mark Schoonover wrote:

Chuck!

What thickness of Al did you use? I take it you have a bending brake of
some sort?

73! Mark KA6WKE

.

Hi Chuck,
Have you ever used press fit or other standoffs so that the ugly screws don't protrude through the bottom of the case? Such as these:

Just curious.

Peter