Small Wonder Labs
PSK-20 Transceiver Kit 03/09/10
2000
3
.
PLEASE READ THE SECTION BELOW BEFORE
REMOVING ANY PARTS FROM THE BOARD
Uh-oh! Sooner or later, you may need to remove a
part installed in the wrong location, or perhaps pull a
component for troubleshooting purposes.
Get yourself a roll of desoldering braid (Radio Shack
#64-2090B). Lay the end of the braid down on the
joint to be cleaned and press the soldering iron tip over
the braid. Within several seconds you'll see the braid
begin to wick up solder from the joint. Remove the
braid and reapply a new section as needed until the
joint is clean. It may be necessary to pull the
component out from the top side of the board while
heating the joint. Leave the iron tip on the board only
as long as necessary to do the job- the PC-board traces
will eventually delaminate (peel off) if overheated.
If that still doesn't do the job, it may be necessary to
cut the offending part off on the top side and pull the
remaining leads through with pliers. Contact me for
replacement parts if necessary.
If you need to remove a transistor, I'd highly
recommend sacrificing the part by snipping it off on
the top side of the board. The leads are best pulled out
singly to minimize the risk of lifting pads.
After removing a component from the board, the
through-hole will probably still be blocked with solder.
Use a dissecting needle or dental probe (explorer),
apply heat to the probe and the board trace
simultaneously until the tool pushes through. Lacking
either of these tools, a round wooden toothpick works
well also!
WINDING TOROIDS:
-Count as you go. Draw each turn snug against the
core to ensure a trim and tight winding
-Double-check the turns count when you're finished.
Use your fingernail or small screwdriver to "bump"
over each turn as you count- this is considerably easier
than counting by eye.
- Trim the excess wire off to about 1/4" and strip the
insulation off the ends with a wirestripping tool.
(
Make sure the stripper is adjusted correctly for the
wire- it should cut the insulation cleanly but should not
nick the wire itself- try this out on a sample length of
toroid wire first
.)
Counting the turns:
If the wire passes through the toroid center hole, it
counts as a turn.
Here's an example:
MATERIALS-
You'll find the following items with your PSK-20 kit:
1- bag of small parts (resistors, caps, wire, etc)
1- antistatic bag (contains semiconductors)
1-
envelope labeled "Zeners"
3- envelopes labeled 'L5','L6' and 'L10'
1- printed circuit board
- (this manual)
(Feel free to reproduce portions of this manual for
personal use. You can then check off the construction
GOOD
SOLDER FILLET IS CONCAVE AND 'WETS'
SMOOTHLY TO COMPONENT LEAD
BAD
SOLDER FILLET IS CONVEX OR DOES NOT
ADHERE TO COMPONENT LEAD
This toroid is wound with 8 turns
Turns must be uniformly distributed around
the circumference of the toroid.
