[Elecraft] DIY DSP Rev D

[Brett Howard]

I'd just also kinda like to know what is different in that I currently
have a rev B board that I've changed out the C9 and C13 I think they
were with 100uF caps.  I used properly sized caps designed for that pad
layout and used professional tools to do the job.  Thus this is the same
as if those caps were put there from a production line. 

I have also installed the LPF daughter card in my unit. 

So if all I need to do is make a few other changes and I'm at REV D I'd
personally rather make those changes to my current board.  My K3 has all
the rest of the mods performed on it and I'm willing to do the work to
keep it up-to-date.  

I already have a Rev. D board on order.  It appears to me that I should
cancel my order and start looking at doing some of the W9AC mods using
SMT parts.  

I'm not saying conspiracy here but I do find it a bit odd that there are
many other application notes explaining how to perform modifications to
make improvements to other audio circuits, and RF immunity improvements,
ALC improvements....  Why not release an app note on the rework needed
and let users decide if they want to carry out the modifications or buy
a replacement board.  

Heck on the negative ALC mod I didn't want a mod that messy in my radio
and they offered to sell a replacement board for a nominal fee.  I
jumped at the time savings (and the fact that the new board used
discrete R's rather than R-packs which Elecraft found to be leaky).
Couple that with the fact that I end up with a much cleaner solution and
I'm a very happy and very informed customer.  In all true honesty I
think the reason why this set of changes is less documented is because
it happened in several stages here and there and people don't want to
spend the time to go back through and find all the changes and make an
app note about them.  But thats just an educated guess from another man
who works in the same field.  

~Brett (KC7OTG) 

On Sat, 2010-01-02 at 07:51 -0500, Don Wilhelm wrote:
> David,
> 
> Yes, Wayne, Lyle and Eric have stated that the results were quite 
> similar to the W9AC mods, but were done in a different manner (I presume 
> it was easier to accomplish resistor changes in board manufacturing).  
> There may have been some other insignificant 'tweaks' to the hardware 
> done at the same time (just because it was convenient).  But there are 
> no functional or performance enhancements associated with those changes.
> I would think if Elecraft had made improvements, they want to advertise 
> that fact, a better K3 should sell better. 
> 
> Some of these questions are beginning to sound as though there is some 
> "conspiracy" going on.  The fact that a board level B can be upgraded to 
> assembly level D (with the component changes and the LPF) says that the 
> board printed traces has not changed. Note that the board level relates 
> only to the printed traces, solder pads, etc.  The assembly level can be 
> quite different.
>  From the information that we have, the original board was assembly B 
> (same as the board level), then the low frequency response was extended 
> resulting in level C - finally, Eric decided to add the LPF since it was 
> available, resulting in assembly level D.
> 
> 73,
> Don W3FPR
> 
> David Cutter wrote:
> > Dave
> >
> > I would gladly fit this daughter board and perhaps do the LF enhancement, 
> > but several on this list seem to be saying that the exchange DSP board does 
> > something more than these mods provide.
> >
> > Can anyone clarify?
> >
> > David
> > G3UNA
> >   
> >
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