On Sat, 14 Jul 2012 12:40:32 -0500, Peabody
wrote:
The relay arrived this morning, and I've installed it, and everything
works fine so far.
Congrats, so far.
I have to keep the old relay in case I ever need to send the unit in
under warranty. So I won't be taking it apart. But, it does rattle
when I shake it, which I think is not a good sign.
It might be a spring. Some DPDT relays have two springs, one of which
might have come loose. With a spring missing, the tension on the
normally closed contacts will be reduced, possibly causing the
symptoms.
By the way, I assume the lead-free solder they're using now has a
higher melting point than the 60/40 I use - it was a bear to get the
thing unsoldered with my 30W iron. Ended up having to add some of my
solder to the pins, then braid it off, two or three times before it all
wicked up and the holes opened up.
A 30 watt iron will work, but I prefer something with a thermostatic
control and at least 60 watts. The idea is to solder hot and quickly,
so that the heat affected zone is minimal. A low wattage iron may get
up to temperature eventually, but I'm into instant gratification.
Mixing unleaded and lead-tin solder is a bad idea. However, I do it
all the time because I absolutely detest unleaded. I clean off as
much solder from the pads and pins with a solder sucker, and then
apply the lead-tin solder. If you get a dull surface finish, you
still have some residual unleaded solder in the mix. Suck and remove
it all, and try again.
I use solder braid only when I can't get a solder sucker onto the PCB.
The problem is that it takes much more heat to remove solder with
braid. If the PCB has tiny traces, or is made from phenolic, the
traces will delaminate. That can happen with a solder sucker, just
less often. If I have to unsolder many pins, I use an antique
desoldering station:
http://802.11junk.com/jeffl/crud/pace-desoldering-station.jpg
And Digikey is amazing. I ordered late Thursday afternoon, and it
arrived in the mail Saturday morning, all for $2.20 postage. Hard to
beat that.
Yep. Great service from Digikey. Mouser, Allied, and Newark are
other good sources of parts and pieces. I prefer Digikey because I
like their online search tool which came in handy trying to find the
relay. However, I will confess that I buy quite a few parts on eBay,
because it's much cheaper.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558