[Elecraft] EC2 Clone (Was The 1500 watt amp)

[Wes Stewart]

Nice work!

I too have built my own enclosures with similar techniques.  A couple of my 
projects can be seen here: http://sadxa.org/n7ws.html#amp

Although at the time I had access to a prototype workshop, I have done similar 
work at home with comparable results.  If possible, I avoid bends.  In all of 
this stuff I used 0.062" 6061-T6 material so it wasn't going to bend anyway.  
The harder alloy drills like a dream. For all of the corner joinery I used 3/8" 
square stock, 8/32 threads and stainless steel screws

In the protoshop, I had access to a shear but all of the sheared edges were 
still smoothed by hand.  I had a granite surface plate and used a vernier height 
gauge for layout so similar parts were interchangeable.  In the home shop I lay 
out as carefully as possible and match drill on a drill press. Most people can't 
tell the difference.  With a lot of elbow grease a hacksaw works, although after 
a lot of furniture building and finish sanding, I needed rotator cuff surgery so 
I don't do that anymore.  With extreme care and I do mean extreme, a carbide 
toothed blade on a table saw will cut aluminum if it's thick enough and the 
blade has fine enough teeth.  Otherwise I use a bandsaw, which is always safer, 
if less precise.

In the protoshop I had access to chemical dip baths for passivating the 
aluminum, silver plating the RF parts and a panograph engraver for panel 
lettering.  Silver looks nice, but is highly overrated as an RF conductor.*  In 
the home shop, before the un-elected bureaucrats in DC decided we were too 
stupid to handle lye (judging by the electorate they may be right), I would etch 
aluminum in a lye bath, rinse and neutralize with vinegar and a final water 
rinse.  This would yield a nice satin finish.  The best I have found since is 
oven cleaner.

Another finish, if you like the look, can be had by using a random-orbit sander  
Play with the grit until you find something you like.  Sanding it wet with a 
little cutting oil can be fun, albeit messy, too.

Tube amplifier still have their virtues and, along with antennas, can be great 
roll-your-own projects that can work better than what you can buy.

Wes  N7Ws

* http://k6mhe.com/n7ws/Plating.pdf


On 8/1/2016 9:36 AM, EricJ wrote:
> If you can build whatever you want, you can easily build the enclosure. Here 
> is an EC2 clone I built last week in about 6 hours. I made the side panels 
> with a hacksaw, file and drill press. The front panel I cut and formed with an 
> inexpensive 8" shear/brake. This one is branded Grizzly, but Harbor Freight 
> has them as well. I didn't use the Elecraft 2D fasteners because I only had 2 
> on hand and didn't want to make a bunch of little fussy pieces. I used 4 long 
> sections of 1/4" square aluminum stock and drilled them with the same hole 
> pattern as the 2D fasteners. The front panel will get painted after I drill 
> and punch it for the current project.
>
> https://flic.kr/p/KBivtc
>
> The smaller K1 enclosure is nearly the same design (slightly different top 
> cover) so it scales down easily. It would scale up for a large amp just as 
> easily. The cost of the EC2-clone was about $4 in materials (0.080" and 0.050" 
> sheet and 1/4" bar stock). All can be built with a hacksaw, file and a hand 
> drill. A bandsaw and a drill press make it more precise. A shear/brake makes 
> it even easier.
>
> Eric KE6US