[Elecraft] DSP/KPA100 combination

[David Wilburn]

Any idea when they will have a solution in place that doesn't involve 
metal working?

David Wilburn
dave.wilburn at verizon.net
K4DGW


charles wrote:
> On Thursday 01 February 2007 14:21, Lyle Johnson wrote:
>> Hello Charles!
>>
>>> I would like to make contact with any builders who are currently putting
>>> together the above combination, or any builders who have recently built
>>> such a combination.
>> I'm anticipating that your request has to do with fitting the DSPx
>> module into the KDSP2, and then having the pins on the 20-pin conenctor
>> interfere with the heatsink on the KPA100.
> Yes you are correct Lyle.  I found that the corner of the pressed metal shield 
> needed trimming and the pins on the surface mount unit to the DSP unit needed  
> to be shortened.
> 
>> The present run of DSPx module have pins that are slightly too long, and
>> the 20-pin receptacle on the KDSP2 board has stops that prevent the pins
>> from "over engaging".  The net result is that the KDSP2 doesn't seat
>> completely on the KDSP2, and the tops of the pins are in contact with
>> the KPA100 heatsink.
>> The solution is to trim the pins on the DSPx module.  If you trim off
>> about 0.090" from the 20-pin male connector pins, it will mate and seat
>> as intended.  The dimension isn't a precise requirement; if you mark the
>> pins between 0.100" and  0.125" back from the tip and then trim you
>> should be fine..
> I actually reduced the length of the pins by 3/32", about .094".
> I did this by cutting the ends off with a small pair of wire cutters, then 
> filing them all to the same length with a diamond lap, then removing the 
> burrs and filing a slightly splayed end so that they easily pushed in right 
> home. The right grade of diamond lap will only remove a little at a time so 
> that the amount being removed can be controlled and a smooth finish is 
> achieved.
> 
> This problem caused me a great deal of bother because the PA worked perfectly 
> first time when it was sitting beside the K2 but when it was mated with the 
> K2 it was impossible to see what the problem was.  All I knew was that I had 
> completely lost audio.  I then realised that this was because the surface 
> mount unit on the DSP was being grounded by the metal shield due to a clash.
> 
> As well as shortening the pins I also had to do quite a bit of filing to the 
> shield to get it to fit properly. The PA is now easily fitted to and removed 
> from the K2.
> 
> Anyway, after quite a struggle and lost time I now have a very happy K2/100 
> which this morning enabled me to work HZ1AN in Jeddah :-)
> 
>> I suggest you *not* use "flush cutting" pliers as these leave the pin
>> ends very blunt.  Normal diagonal cutting pliers will do the job just
>> fine.  You do *not* need to grind or file or sand them to have pyramid
>> tips.
>> Finally, you might want to use a felt-tip pen to mark the pins to be
>> cut. This helps to trim them to about the same length, although this is
>> not critical.
>> Sorry for the error on the DSPx pin lengths...
> 
> All's well that ends well !!
> I just wanted to make other builders aware of this problem and the way in 
> which it can easily be solved - when you know how.
> Gary Surrency has told me that Elecraft intend issuing a "Builder's Alert" 
> about this issue but I haven't seen it appear yet.
> 
> Thank you for your reply Lyle.
> It's an absolutely super radio and with the KAT100-1 sitting underneath it's a 
> very useful tool for a CW op. My thanks to Eric for the design and to Wayne 
> and the rest of the Elecraft team for providing me with hours of satisfaying 
> fun in building the kit and for many, many more hours of operating yet to 
> come.
> 
> 73 from Charles - M0BIN
> 
> 
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