[SixClub] Station grounding

Sun Feb 27 15:40:12 EST 2005

Don't misunderstand me. Either solder or use a mechanical connection. Do 
NOT tin and then use a mechanical connection. That is the failure mode I'm 
talking about.

The rectification problems I saw were a result of somebody that decided 
that he was going to use a barrier strip of screw terminals for the monitor 
runs where they came out of the pipe, for some reason, and run from the 
barrier strip to the board. Not too bad so far, but he did the same thing 
with all the mike inputs, and he tinned many of the wires first. After five 
years, several of them were mini-radio stations. Many of the screws that 
were originally very snug had another turn or two to go to achieve the same 
level of tightness. I re-tightened the screws and all but one stopped 
rectifying-- that one, I cut and reterminated without the pretinned wire. 
That fixed it. A few years later you could hear local stations with the 
gain way up and no signal. Eventually I would have had to resnug again but 
by that time the initiative to scrap the whole installation and move it out 
of that closet to another area was well under way and it all became moot.

Grounds for noise reduction and health/safety at 120/240 and other voltages 
under (arbitrarily) 600v I'd say solder. Like you, I've been soldering 
since my first Heathkit in the 60's with grandpa, and I can make a good 
solder connection without really thinking about it, a better one if I DO 
think.

But for lightning protection, I'd still crimp it. Your house ground system 
is based on a wire clamped to a pipe, probably, and most folks' ground wire 
is clamped or screwed to the ground rod, not soldered, although some do 
solder.

At 11:13 PM 2/26/2005 -0800, you wrote:
>Really?
>
>So, lets crimp components to the pc boards instead of
>soldering them! LOL!
>
>Seriously, I have been doing professional audio work
>for the last 20 years, as well working as an
>electronics technician, and it is the first time I
>hear something like that!! Did you know that
>professional studios use soldered patch bays instead
>of the most common type that uses rear patch cords?
>Why? because mechanical connections do get rusty!
>Oxigen gets into everything, no matter how tigth it
>is. Professional speaker manufacturers know that, that
>is why they are using SPEAKON high current connetors
>instead of the good ol' bind posts. But we are not
>talking speakers here, do we? It is all on how good
>your soldering is and, boy, you would not believe the
>mayority of people don't know how to solder properly.
>A good soldereing is clean and shiny, with no blobs
>and very low in resistance (.2 ohm typical). A bad
>soldering is dull, bulky and high in resistance. The
>diode problem you mention happened when you used a
>water pipe as a ground. Pipes were soldered with a
>different type of solder; 40/60 acid core, while
>electronis uses 60/40 rosin core. Pipe soldering goal
>was never inteded to be good, electrically speaking.
>That is why they advice against using water pipes as
>grounds. Building code now specifies using PVC
>plumbing in houses. So, old buildings that had
>previous metal plumbing are getting mixed up with PVC
>at some point, so a ground path can not be assured.
>This will turn the plumbing into an antenna! A
>properly done soldering isolates the copper from the
>oxigen in the air thus preventing oxidation
>
>If you read closely my post, I advised to solder a lug
>to the flat braid and that lug is the one that gets
>tigthten to the screw of the terminal block. 60/40
>rosin core solder is hard to oxidize because it is 60%
>tin and 40% lead. The solder used in pipes is 60% lead
>and 40% tin, so it is a softer soldering, prone to
>breaking if stressed. Then you add the acid core...!
>
>By the way, Galena is Lead Sulfide, not oxide. It is a
>different compound. It is an ore.In fact, most lead
>and silver comes from it. Read more here:
>
>http://mineral.galleries.com/minerals/sulfides/galena/galena.htm
>
>One last advice, always test your grounding with a
>good digital ohm meter. You should get less than .3
>ohms on a mechanical connection for it to be
>considered as good. More than .5 ohms is crap.
>
>When a lightning struck my site last year, I only
>lost my preamp, for obvious reasons. All the radios
>fared fine, and I repaired the preamp, yeah I soldered
>the new GaAS FET, as they did in factory.
>
>My two dollars ;-)
>
>Gabriel
>
>
>--- Tom Peters <tpeters at mixcom.com> wrote:
>
> > I wouldn't solder, I'd use a very tight mechanical
> > connection, such as a #8
> > screw.
>
>=====
>Gabriel Sierra
>Moondancer Recording Studios
>moonrec at prtc.net
>http://www.moondancer.freeservers.com
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[Commentary] Businesses may come and go, but religion will last
forever, for in no other endeavor does the consumer blame himself for
product failure.
--... ...--  -.. .  -. ----. --.- --.- -...
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