[Elecraft] Murphy's Law of Kit Building

[Don Brown]

Hi

The Elecraft circuit boards use the convention of making pin 1 of a multi
pin part round while all other pins are square. A few times I have found
myself missing pin 1 because I get fixed on the square pads and think the
round pin 1 is a feed through or not part of the pin row. I have the most
problem with this with the relays and some of the IC's. This is one reason I
always heat all of the pins on the relays and IC's twice. I will first
install the part and solder all the pins quickly. Then I go back to the
first pin soldered and reheat each pin without adding more solder or wiping
the iron except for the first pin. This has several benefits. If there is
too much solder on one joint and not enough on another not wiping the iron
seems to even out the the solder on the pins. It also burns off some of the
flux and the main benefit is it makes me look at all the pins again so I
will see a pin missed. When I do the reflow It is very quick. I touch the
pin with the iron and watch for the solder to flow. As soon as the solder is
molten over the entire pin I move to the next.

I also look at each joint while clipping the leads of resistors and
capacitors rather than just holding the board over the trash can and blindly
clipping all the leads. This forces me to examine each joint one more time
as I am clipping the lead. I have found a missed joint several times using
this method. I also save the 1N7000 diode leads for jumpers and ground test
points.

I find the added time to do the above is very small and could save a lot of
troubleshooting later in the testing phase.

Don Brown
KD5NDB


----- Original Message -----
From: "Carl J. Denbow" <n8vz@fptoday.com>
To: "Elecraft Reflector" <elecraft@mailman.qth.net>
Sent: Wednesday, January 01, 2003 10:17 PM
Subject: [Elecraft] Murphy's Law of Kit Building


MURPHY'S LAW OF KIT BUILDING

If you forget to solder a connection, it will be in a place that will
be covered up by other parts and will not be discovered until said
"other parts" are in place!


This is my conclusion after spending two hours de-soldering the LCD,
reflector, etc., so that I could solder pin 1 of U1.  Somehow I had
failed to solder it; hence the infinity readings I got on that pin
during resistance checks.

Another conclusion:  soldering is fun; de-soldering is NOT fun! ;-)

73 to all!

Carl