On Jul 26, 2:33*pm, doug wrote:
hello all, * does anyone know if my icom 7400 txvr., bought new in jan.
2004, circuit boards were
assembled using `lead free` solder,or leaded solder,and can leaded
solder be used to repair or
replace parts even if original assembly was `lead free` *The sevice
manual doesn`t mention this,
and tried Googling for info. with no success *!

thanks for any info. * * doug.

No need to wonder. Heat up a soldering iron so it will melt some tin/
lead wire solder. Small 63/37 will work best. Find a place on a board
where you can get an iron onto the solder on the board. See if you can
add a tiny bit of leaded solder to what is on the board. If it melts
and joins the board solder, then your radio uses leaded solder. If the
board solder will not melt to join your leaded solder, then the radio
was built with lead free solder.

Since lead free devices were first required in the EU on July 2006,
lead free solder certainly was not a requirement. Asian countries
followed the EU by a year or so.

Another clue is if the insulated wiring in your radio uses PVC
insulation. Lead compounds are used to keep the insulation flexible
and would probably not have been used in a lead-free device. Also look
for tinned wires. Lead-free will use silver plating and probably
teflon insulation.

Also look at the connectors to see if they are tinned rather than gold
flashed. Another good clue.

Lead solder can certainly be used to repair a lead free solder
connection. The problem is in getting the lead-free solder hot enough
to melt with a common soldering iron. If you are removing/.replacing a
SMT component on a circuit board, the usual method is to just clip the
leads, if possible, then use a suitable soldering iron to clean up the
pads. Then use your leaded solder to place the new component. If you
have some solder paste, use that on the pads before placing the new
component, but you can use thin wire solder just a well.

Be sure to clean off all the flux.

Good luck
Paul, KD7HB