This is Page 1 - Boardmaker instructions
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To follow along with these pages you should go here
and print out the layout diagram for the 5F6A Bassman board. |
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I will first define the
items you will be using.
A piece of 1/8" thick glass/epoxy circuit board material.
The metal drilling template. This 1/4 inch thick metal item that has
over 500 holes in it. This is the tool that makes it all possible.
The drilling mask. The mask is a fiberglass template that only has the
holes for the particular circuit board that you are building. The mask looks
like a drilled circuit board with all the 3/32 holes, but it is only 1/16"
thick.
Two 3/32" metal alignment pins. (included with drilling template)
Drill press.
3/32" drill bit.
3/16" drill bit.
A clamping device like a vice grip or something similar. You could probably
use tape if you were careful so that pieces do not move while drilling the
two alignment holes.
Lug tool. See this page.
Lug press. See this page.
Bent tip needle nose pliers. See the photo below.
Wire cutters.
Wire strippers.
24 gauge bare buss wire. Radio shack sells small spools of buss wire.
40 watt soldering iron. Radio shack 64-2071C 40W iron works great.
.032 solder. Radio shack part number 64-009A works fine.
1 small and 1 large component lead bender. See
this page. |
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| Cut your piece of 1/8" thick circuit board a tiny bit longer than the finished length. I use a
jigsaw with a fine tooth blade that is able to cut metal like materials. The
circuit board material is very hard and dense. Most likely you will not be
able to cut the ends of the board perfectly square so cut your board a bit
longer. Sand the ends of the board so that they are nice and square and to
the proper length. I use a bench top sander that has a 9" round disk and a
long 6" x 48" belt. I sand the ends of the board square on the 9" disk and I
sand the long edges on the 6" x 48" belt. |
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Clamp your blank piece of board to
the rear of the drilling template. You will align and clamp the board in the
upper left corner of the drilling template. You always use the left end of
the drilling template as your starting point. |
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While the board is
clamped to the drilling template, drill a pilot hole at each end of your
circuit board using a 3/32" drill bit. These two holes that you drill are
holes that you will be using to install lugs into so only drill a hole at
each end of your board that are actually holes used in the circuit that you
are building.
I always use the line of holes that are 20mm down from the top
edge of the drilling template. This line of holes is always used on all my
board kits so there is no danger of drilling a hole in the board that will
not be used. The two pilot holes I always drill are the first lug at the
left edge of the board and the first lug at the right edge of the board.
After drilling the two pilot holes, unclamp the drilling template from your circuit board.
Tip: The more you use your 3/32 drill bit, the smaller the outside diameter will get. Eventually the drill bit will not be useable because the drilled hole size will be too small. If the lugs will not go into the hole or are difficult to press into the hole, it's time for a new drill bit.
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| Left edge |
Right edge |
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Put an alignment pin into each
of the pilot holes that you drilled in your circuit board. You will have an
alignment pin at each end of your circuit board.
Slide the metal
drilling template down onto the two alignment pins. Slide the
fiberglass-drilling mask onto the two alignment pins. You should now have
a stack with the blank circuit board on the bottom, the metal drilling template in the middle
and the fiberglass-drilling mask on the top.
You will be drilling only the holes that the mask has on its surface. That
is why it is on top of the stack. There are over 500 holes in the drilling
template but you only want to drill the holes on the mask.
Mask tip: I use a red sharpie pen and connect all the dots on my mask so it
is easy to see the holes that have to be drilled. |
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Drill all the holes that are
on your mask using a 3/32" drill bit. Your drill bit will pass through a
hole in the mask. Then it will pass through a hole in the metal drilling
template. Then the drill bit will actually drill a hole in the fiberglass
circuit board material. After you have drilled all the holes you can hold the whole assembly up to a light and look through to make sure
that you haven’t missed drilling any holes. Disassemble the mask, drilling
template and circuit board. |
| How to make a 4 power tube
circuit board |
To make a 4 power tube version of any
board you just add two more cathode/1 ohm bias checking resistors and two
more screen grid resistors. To do this, you drill all the holes in the mask
starting from the left end and up to the cathode-screen grid resistor
section and then stop. Do not drill past the last screen grid resistor, you
are going to stop and shift the mask to the right.
Drill all the way to where the cathode resistors/1 ohms and screen grids are
located. Then shift your drilling template to the right and drill another
set of cathode/1 ohm-screen grid resistors. You can put all four cathode/1
ohms in a row and all four screen grids in a row or you can just double the
pattern on the drilling mask.
When you are done you will have 4 cathode/1 ohm resistor holes and 4 screen
grid resistor holes.
Now continue drilling all the holes to the right of the last screen grid
resistor. |
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Drill the circuit board
mounting holes using a 3/16" drill bit. The reason I use a 3/16" drill bit
is because I use #8 screws to mount the circuit boards to the chassis. A
3/16" bit is about right for a #8 screw. I usually drill a hole in all four
corners of the circuit board. If the circuit board is longer than 10 inches
I will also drill two mounting holes in the middle of the board. In other
words I will have 6 mounting holes in a long circuit board and 4 mounting holes in
shorter circuit boards. I usually drill my mounting holes about 1/4" from the edges
of the board. I drill the mounting holes by eye. You don’t use a template to
drill the mounting holes. One reason for this is that your circuit board
lengths and widths may vary a bit and the mounting holes might not end up
where you want them. Now you should have all your holes drilled in your
circuit board. |
| Do any finish sanding that you may want to do. I usually do a quick wet
sanding on all circuit board edges with a very fine grit emery cloth to give
the edges a nice clean edge. Wash your circuit board with soap and water
to get rid of fingerprints, grease, oil, sanding dust, drilling dust and any
other particles. Dry the circuit board with a cloth or paper towel. |
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Push all the turret lugs into
the circuit board holes. Make sure you are putting the lugs in correctly with the
board facing up. Double-check yourself, if you install all the lugs on the
wrong side of the board, the board will not be useable. I speak from
experience, it has happened to me. Before you swage your lugs, make sure they are all pressed down flush with
the surface of the circuit board. If you swage a lug that is not down flush
on the board surface it will not be installed correctly. In other words,
push all the lugs into the board as far as they will go. Swaging a lug is
the process where the lug press flares out the rear of the lug so that it
permanently attached to the circuit board.
I have my lug press set up so that the tool
with the hole is on top and the pointy tool is on the bottom. That way I can
push all the lugs into all the holes on the circuit board and then I go over
to the lug press and carefully swage all the lugs. Be careful not to knock
any of the lugs out of their holes while handling the board.
Now swage all your lugs on your lug press.
Look at the back of the board after you are done to make sure that you
swaged all the lugs. Your circuit board should now have all the lugs
installed.
This page has instructions on how to set up
your lug press and how to swage the lugs.
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