[Elecraft] Re: KPA100 assembly question

[Bob Nielsen]

Wayne,

The manual mentions shorter standoffs at the front edge but those are
where the heat shield is installed.  I am referring to an earlier step
on page 35 where the five 3/8" standoffs which support the PC board on
the heatsink are installed (there are also two standoffs which are part
of the pedestal).  The heatsink has a milled area at the back where the
standoff nearest the fan is mounted which is ~.025 or so below the rest
of the heatsink, so that standoff is lower than the others.

Bob


On Tue, Jun 03, 2003 at 08:44:00AM -0700, Wayne Burdick wrote:
> Bob, 
> 
> All seven milled standoffs in the heatsink should be at the same level. The
> additional surrounding mill depth in the part of the heatsink that you mentioned
> is taken into account. So there should be no gap between the standoffs and the
> PCB at any point. If there is, it must be due to very slight warpage of the PC
> board, which is unavoidable in boards of this size. So you should not need a washer.
> 
> Remember to put the two shorter standoffs at the front edge of the heatsink,
> corresponding with the reduced height of the shield in this area. This is
> explained in the instructions.
> 
> 73,
> Wayne
> N6KR
> 
> Bob Nielsen wrote:
> > 
> > I inserted the setscrews into the heatsink and threaded the standoffs
> > onto five of them.  The one near the back center is at a lower level
> > than the others, since the portion of the heatsink where this is
> > installed has a section milled below the rest of the heatsink.  When
> > the pc board is installed it rests on the other standoffs but there is
> > a ~.025 gap between the board and the standoff at that position.  Is
> > this correct?  Should a washer be installed to support the board?

-- 
Bob Nielsen, N7XY                          n7xy@n7xy.net
Bainbridge Island, WA                      http://www.n7xy.net
IOTA NA-065, USI WA-028S