Charleston Receiver Building Party (Long)

[Frank Gentges]

tacoistas,

Several of us gave up Saturday, August 29th, to build our Charleston 
receiver boards instead of meeting at Tippy's Tacos.  We ended up with 
10 almost complete receivers.

First, I lay awake Friday night as I thought up a way to build a better 
arrangement for squeegeeing solder paste through the stencil onto the PC 
boards.  Saturday morning I started on the new jig and as arrivals came 
in we got more and more help on building it up.  After some adjustments 
it was a good design.  Joe Sluz, WS3W, was one of our builders and came 
down from Ellicott City MD.  Joe had a sharp eye and microscope and put 
the final adjustments onto the alignment.  He started putting solder 
paste onto the PC boards and before long the boards were coming out 
ready for parts placement.

We put the parts into little bins and then made enlarged copies of the 
silk screen with each page devoted to each part. This was suggested by 
John Schwacke to Terry Fox and thence to us. The sheets were punched and 
mounted into a loose leaf notebook.  As parts placement proceeded, the 
sheets were flipped over, the parts were pulled and provided to the 
people doing the assembly.  Rob Bowers, KA0SER manned the parts bins and 
kept Corky Searle, Bill Fenn and Rob Seastrom with the parts and 
placement info.  Each position had a means to hold the board in position 
and a magnifying glass.

As this assembly proceeded, Joe Sluz and Tom Azlin started a group of 
seven boards putting one type of part on all seven boards.  By switching 
between each other they kept from getting stressed out and went through 
the parts placement for all seven boards.  This approach seemed better 
than doing just one board at a time.

We ran into a problem as some of the voltage regulator chips were in the 
wrong device package.  Those devices were skipped and will be put on 
later with a soldering iron.

Joe had good experience using a toaster over as a reflow soldering oven 
so he manned the toaster oven and soldered the boards much as one would 
do a pop tart.  By carefully watching, the solder paste started to look 
shiny and once all the paste looked shiny, the oven was turned off. 
After a short cooling period the boards were removed.  This part went 
really smoothly just as if we knew what we were doing.

Then each board needed close inspection to fix solder bridging at the 
fine pitch IC leads.  One of these fine pitch ICs ended up one lead over 
and was moved to the correct position.

The correct voltage regulator chips are on order and should be in this 
week and we can get people together to put them on if needed.

Rob Seastrom went out to pick up great pizza for lunch.  We had a fun 
time working together as we all learned how to do this kind of assembly 
work.  We had a great chance to meet and work with AMRAD members we have 
not worked with before.  Hopefully this won't be the last.

I know this is a little long but maybe some future Charleston building 
parties can use some of our experience to make it as painless as possible.

P.S.  I had ordered a nifty little solder paste printing frame on eBay 
and suddenly got a message that the shipment had been voided thus 
requiring us to build our own.  Sunday night, I got an email that the 
shipping had been straightened out and it would arrive this week.  Oh 
well I can use it next time.

Frank K0BRA