[DSP-10] DSP-10 Completion

[dsp-10@mailman.qth.net]

Good Evening to All,

I would like to add my comments to those already posted here.  What a great 
project!  I finally completed my unit yesterday after several months of 
delays (most of which were not related to the DSP-10).  I've spent all day 
playing with it.  What a super toy.  Thanks to Bob for all his hard work and 
to the TARP guys who made the whole process enjoyable.

I changed C117 from 10pf to 6.8pf during construction as suggested by KO7N 
and W7CQ.  As suggested by Bob, I also connected a ground from the R105/C113 
junction and adjusted L102 for 123.5 Mhz during preliminary checks.  When I 
installed the EZ lite board the PLL locked from below 144 to above 148 
without touching L102 at all.

The only problems I encountered were self inflicted.  One of those was a 
pretty big deal.  Midway through checkout I lost PLL lock.  After flailing 
around in the dark for a while and changing U104 twice, (once on speculation 
and once because I blew it up with a meter lead)! Common sense set in and I 
ran diagnostics.  The serial diagnostics showed me that I had lost the serial 
data stream (FL0) at pin 33 of P3 on the EZ lite board.  A new EZ lite board 
fixed the problem -- though the pain persists!

Apparently one of the things that you don't get with the new boards (in 
addition to the dos software) is a user's manual.  I got the impression from 
a reply I got from a previous post that user manuals came with the earlier 
models.  Is it practical, and would someone be willing, to make a copy of a 
page or two from the manual which would allow me to diagnose the loss of FL0? 
 The processor still works OK.  I get the blinks on the LED and everything 
else seems to work.  If the signal comes from the CPU it may be an exercise 
in futility anyway.  I'm not sure I'm up to changing a 128 pin flatpack!

Thanks for the help and the bandwidth and again my thanks for a great project.

73 de Jess - W4MVB




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