From a message from Chuck Adams, K7QO, to the QRP-Tech list:
OK, the rush is on. I figured out what I want to do and now
the race is on to
use up over 1,000,000 parts before the
estate sale. :0)
And you know I
have to show this to every one, whether any
one uses it or not is up to them.
I fell into the following MUPPET
technique through trial and
error.
Manhattan Construction: Jim, K8IQY, 1998 winning of Dayton contest
started it.
<
http://www.k8iqy.com>
<
http://wdv.com/Electronics/Fab/ManhattanConstructionTechniques.pdf>
and
then there is the variation on this using the 'Island cutter' or
a
special
diamond circular shaped drill for making pads. Generates hazard
dust and
I have yet to see some one that can make the same pad every
time. I
don't know of a tutorial online that shows using a drill stop to
get
uniformity. IMHO.
Ugly Construction:
<
http://www.qrp.pops.net/ugly.asp>
<
http://www.arrl.org/files/file/Product%20Notes/chapter_1.pdf>
<
http://www.sm0vpo.com/blocks/deadbug_0.htm>
<
http://www.alg.myzen.co.uk/radio/qrp/ucw.htm>
and about
16,000,000 other sites with a Google search engine.
Professional
Construction:
<
http://www.youtube.com/watch?v=xm9vW2I-41g>
And using
all of the above I'll call the 'MUPPET Construction'
for
Manhattan-Ugly-Professional Placement Experimental Technique
for
construction of electronic circuits.
Now, unless you have been hiding in
a cave for about 20 years,
all of the above should be familiar to you, except
MUPPET. For
lack of a better name, it is the term I will use for collecting
all
the techniques together to build something.
OK. Going to the known
techniques. What is it that you like and
don't like? How about expense to get
started, other than the parts?
Ugly. Requires a supply of high valued
>1Mohm resistors for standoffs.
But is is quick and easy. Some times
difficult to debug for some else
that did not build the circuit. What is this
gismo here for? ...
Manhattan. Nasty super glue and doing the layout.
Harbor Freight or
similar punch, some people have difficulty finding. Takes
time to place
the pads and let them set.
PCB. Layout time. AND,
something no one bothered to mention.
Drilling a lot of holes and getting
them all centered is a royal
pain.
--------------------------------------------
You still are
going to be out some expense for equipment. For MUPPET
you will need a PCB
shear/cutter and some cheap items for doing
PCB etching. Don't give me grief
about the muriatic acid. Just
kill it with backing soda when you are done and
flush.
Here is an example out of the gate. Just a simple VXO test
fixture
to determine why I could not get constant startup on a VXO in a
project.
<
http://www.k7qo.net/p4110006.jpg>
Then
I got excited about not having to drill holes, I can do Manhattan
layouts and
as you will see I magically came across a tool that costs
very little and
makes things entirely repeatable as many times as you
want.
For the
Manhattan projects and my stuff spread around the Internet
like bread crumbs
in a fairy tale, I constantly get emails about how
I laid the project out and
what software did I use and how I wrote it.
This new technique uses
expressPCB for the layout. I just the layout
on the top layer. ExpressPCB,
for economical reasons, does not
print out the top layer so that you can
easily use the toner transfer
method to make a PCB.
Here is how I get
around that limitation. I generate the PCB and
then 'print' it out, but not
to my Samsung laser printer. I print it to
a 'PDF' printer, i.e. the image is
sent to a file and converted in the
process to PDF format. I can now
manipulate that to 'reflect it'
about the vertical to get a reverse image,
like you do for iron on
shirts, in PDF format and then print that. So now I
can do double
sided boards if I ever want to. The reversal is done using a
package
called PDFjam for linux and is most likely available for
windows.
OK. Here is the most valuable tool for PCB
layouts.
<
http://www.k7qo.net/p4120009.jpg>
Using the vector
board I get exact distances desired between
component legs and when I bend
them they will sit FLAT on the
surface of the PCB. And before removing the
component from
the board, I cut the leads sticking through the other side to
get
the exact same length every time. As it turns out, it is about
0.1",
the same and the standard IC pin spacing and the same
snap points in
ExpressPCB. I use 0.1" SMT pad sizes for the
solder points and 0.2" spacing
in most cases so that I get
the neatest placement possible.
I can use
the vector board edge to bend resistors to get
vertical placement on PCBs in
kits and here. Each one
will look almost exactly the same. Try it. You'll
like it.
OK, here is a XTAL OSC that I built up in less than an
hour,
from start to finish. Yes, you can do it quicker. But I wanted
to
able to reproduce the circuits numerous times, if needed,
and now I can
easily share them without having to go through
hoops to get the same layout
to you or any one else.
<
http://www.k7qo.net/p4120007.jpg> Board before
populating.
<
http://www.k7qo.net/p4120008.jpg> See how neat the
transistor sits?
<
http://www.k7qo.net/p4120013.jpg> XTAL OSC
complete.
<
http://www.k7qo.net/p4120014.jpg>
Running 11.040MHz crystal.
Side effects. You can do, on the PCB plane on
the sides:
Ugly mods and add ons or replacements for larger
projects.
Manhattan pad placement for mods, add-ons, etc.
Note. With
judicious placement of text, you can document
parts placement for help in
building and later showing
someone where you put things and why. Also will
help
in debugging something years later.
And just as an experiment. I
promise not to cheat.
I will, at 2200UTC, right after posting this email, I
will go back
to the lab. I will not eat, nor will I rest until I have done
the following
two projects from scratch.
1. Project 001. The HP 8640jr
project.
2. Project 004. The G3UUR xtal osc and parameter fixture from
QQ.
I want to do this and then show-and-tell the items at
tomorrows
flea market/hamfest at DeVry Institute here in PHX AZ and the
AZ
QRP luncheon just down the street at the burger place.
FYI and
enjoy,
chuck, k7qo (the lab rat #2, since #1 is already taken in NH)
:-)
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