[BC] Soldering D-sub Pins

[Thomas G. Osenkowsky]

> Soldering after crimping is only necessary if the crimp is defective.

I would like to comment on this. The events described are
true. They really happened as told. In February, 1987 I was
hired to assist in some engineering duties in St. Maarten.
The person who 'hired' me was a very well respected
individual in the broadcast industry. He insisted that I
solder all the terminal strip spade lugs, despite the fact
that I use a ratcheting crimp tool. Despite showing him
the excellent mechanical crimp, I was told to solder the
connections. I complied.

Some years later, I did some crimps and did not solder 
them. A year or two after that I was told the right channel
on the Otari MX-5050 did not play back through the board
(LPB Signature II). I heard the test tone on the XLR rear
connector but did not hear it on the terminal screws inside
the LPB. By chance the clip lead on my hi-z headphone
brushed on the strands of the wire on the spade lug. The
tone was there! Despite the mechanically secure connection,
enough oxidation built up causing an electrical open circuit!
I should point out that 1/4 mile away from the studio is the
Great Salt Pond. The person who 'hired' me had sadly passed
away but I then understood why he wanted the connections
soldered. Another time the unwelded connection from the
RF feedpipe to the tower electrically opened. I told them
to wire brush clean both sides and that solved the problem.
Welding the joint was the permanent cure.

I was retained by a dark AM station to redesign a phasor for
their two tower array in Long Island, NY. The AM was
taken dark due to lackluster sales. When the FM was sold,
the new owner wanted the AM also. They had given away their
RCA tx and phasor components to some local hams. They
got back some coils but not caps. I used some RG-213 as
a phase shifter to save on component count. They bought a
new solid state AM tx. When it came time to turn on the tx,
it had supply voltage but no RF output. Not having a scope
on site I theorized that there was no PDM signal going to the
PA module. Not having RF to drive the antenna monitor,
check monitor points, I had to make a second trip. The
manufacturer quickly shipped a new tx. Upon inspection of
the defective one, I was proven correct. They used crimp pins
on the D-Sub connector between the two sections. The pin
for the PDM signal had pulled out of the crimp.....

Tom Osenkowsky, CPBE