[1000mp] Making Mods

[Ian White, G3SEK]

Bob Main wrote:
>>>For those of you who have made mods requiring soldering on the 
>>>circuit boards I have a very simple question.  Will a 20w iron be 
>>>small enough or do I need to get a 15w iron?

>> That should work just fine. I use a 800 degree tip on my Weller 
>>station  for all my circuit board work.
>>
>> Good luck!
>> 73
>> Jim W7RY

What really matters is to do it quickly and get it right first time. 
That way, nothing stays too hot for too long... which is where the 
damage can be done.

Iron wattage is not a problem at all. It's mostly about the size and 
temperature of the tip.

Use a pointed tip, so you can heat only the parts you want. Most damage 
is done with tips that are too big. Go for a shape as close as possible 
to a sharpened pencil. This helps you work quickly and accurately, 
because it puts the greatest possible mass of hot copper right behind 
the tip.

Like Jim, I use a Weller #7 tip (800F). With a range of different tips, 
I use the same 45W temperature controlled iron for every soldering job 
from tiny SMD up to big brass boxes. (The same iron works great for 
PL-259s too, if you pre-heat the plug body with a hot air gun.)

It's very important to use thin solder for SMD work. Normal 16g is too 
thick, so you can't control the amounts of solder you apply. To take 
unwanted solder off again, you then have to re-heat the joint... which 
is exactly what you don't want! A small reel of thin silver-loaded 
solder will cost several dollars, but you don't use much so it lasts 
forever.

Bottom line: don't use tools you have to fight! Use tools that will 
*help* you do small soldering. If you don't already have them, buy them 
now - you're going to need these more and more in the future.


-- 
73 from Ian G3SEK         'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek