NC40 MOD

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From: Doug Hendricks (dh@deneb.csustan.edu)
Date: Sun Feb 20 1994 - 20:39:25 EST


I just finished one of the easiest mods to make on the NorCal 40, and it
really adds to the mechanical stability of the unit. Terry Young, KC6SOC,
came up with the original idea, I just changed it a little.

The front and back panels of the NC40 case are attached to the circuit
board with the controls. The back panel is really stable, but the front
one tends to wobble just a little. Terry's fix was to put a piece of 1/4"
rod from the middle top of the front panel to the middle top of the back
panel, sort of a reinforcement bar. I liked the stability, but I did not
like the fact that the bar was in the way when you took the top off, and
also, I plan on adding the Jim Pepper digital readout, and the bar would be
in the way on the top. I thought about putting one in each top corner, but
the easiest way was to put the bar on the bottom of the case, underneath the
circuit board. It was easy, all that it takes is a piece of 1/4 inch rod,
two 4-40 x 1/4 inch pan head screws, a hack saw, file or sander, drill and
#43 drill bit, 7/64" drill bit, and a 4-40 tap.

Jim Cates, WA6GER, picked the rod up for me in Sacramento, he was able to
get aluminum 1/4" rod a lot easier than I can here in Dos Palos. I measured
the depth of the circuit board from front to back, and found it to be exactly
4.25". Note, be sure to measure your board, and add 1/8" to the length.
I then cut the rod into a piece that was 4 3/8" long with a hack saw,
and used a file to square the ends. I then put it on my electric disc sander
and got the ends perfectly square and cut to length. Next, I used a center
punch to mark the center of the rod on each end, and used my drill press and
#43 bit to drill a hole about 1/2" deep. It was then a simple matter to tap
the holes for 4-40 threads and the bar was done.

I found the center of my panels to be 2.25" and measured up .25" and marked
the spot with the center punch. I then drilled a 7/64" hole in both panels.
Assembly is easy, and when you get finished, the case is much sturdier. Oh,
be sure to check that the bar does not short out any of the leads on the
bottom of the board. I had to trim the leads on the RIT pot to get enough
clearance.

Thanks to Terry Young for the original idea, and thanks to Jim Cates for the
aluminum rod. (He made me promise to make him a couple of the rods, so I
will have to pay him off, never know when I will need more supplies.)

72, Doug KI6DS


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