Re: Transmitter Mods

Jerry Gaffke

Not many of us need to use 0201's.
Thank goodness.
It's like working with grains of salt from the salt shaker.

For hobby work down to 0603's (half the size of the uBitx's 1206 parts),
reading glasses and a bright light are usually good enough (for a nearsighted 63 year old).
I'm giving imperial sizes here, where 0603's are 06/1000 of an inch long, 02/1000 wide.

A temperature controlled soldering pencil that gets hot enough,
a clean small conical tip, thin 40/60 leaded solder,  solder wick, and tweezers
are most of what you need to be successful with surface mount.

I usually use 0.4mm  (0.015") leaded solder around surface mount parts, 0.8mm for bigger stuff. 
The no-lead solder has a higher melting point and is harder to work with.

Working on a cookie baking tin can help coral wayward surface mount parts.
If they hit the floor, I get my eyeball level with the floor and sweep the area with
a strong flashlight.  Helps to have a clean floor with no rug.

Be paranoid.  Make sure you have the correct part in hand before soldering it in place.
It can be very difficult to find the faults if something got built with the parts stirred up.

This paragraph stolen from post 37891:
When building a kit, I check all the C's and R's before soldering them in place.
(I have not tried either one, but do have a cheap $10 DVM with capacitance range that is accurate to about 20pf)
When measuring small value caps, be sure to subtract the reading you get with  just the leads hanging out there.

If you want to measure inductors too, and want to know at what frequency a cap or inductor
starts behaving like an inductor or a cap, consider Kee's AQRP Vector Impedance Analyzer
near the bottom of this webpage:

I saturate the solder wick with water soluble liquid flux when cleaning up solder
bridges and other messes, but some varieties of the liquid fluxes are very caustic and you
must be sure to clean them from the board when done. 
Flux can eat right through a copper trace in a few days.

Don't have a binocular microscope at home as they are spendy, but have considered getting one.
Very nice for identifying parts, and seeing bad solder joints.
A cold solder joint on an 0402 can look fine, under a microscope it's very clear what went wrong.

The uBitx is laid out with plenty of room between pads, seldom trouble with shorts.
But with closer pad spacing, there can by filaments of solder (be it leaded or no-lead) between pads
that are impossible to see without magnification.


On Mon, Jun 11, 2018 at 08:59 am, Tom Christian wrote:
Thanks for the input, guys!  I was working with no magnification and "regular" soldering tools.  Sounds like the right equipment would open up a whole new world! .....:) Will follow up.

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