Re: CR Mics

["The Bernadettes" <mdestefano@xxxxxxxx>]

Hi Robb,
    I really don't think I can help you undo the damage done.  Don't feel
bad I've done the exact same thing once before.  But I'll give you some tips
so as not to do it again.  You very likely got the connection too hot while
soldering and caused the small coil inside the element to short out to
itself lowering the output.

First don't use a soldering gun, there worthless, use a soldering iron.
Preferably one somewhere in the 25 to 40 range, if it's an adjustable iron,
set it to the lower range, around 25 or 30 watts.

Use a heat sink, this is a must when soldering on mic elements.  What's a
heat sink you ask?  It's a small plier kinda thingy that you clamp on the
terminal between the element itself and the part of the terminal that you
solder to...this draws the heat of soldering away from the element.  You can
buy soldering heat sinks at any electronic supply store like Radio Shack but
a surgical hemostat works great.  Basically you use it like a "roach
clip"....(remember those!!)  ;-)  In fact if you have an old roach clip
hanging around, you can use that as a heat sink.

Use good soldering technique.  First try to get a decent mechanical bond
between the lead and the terminal.  Make sure the area to be soldered is
clean.  Cleanliness is next to godliness when it comes to soldering...same
goes with your soldering iron tip.  Make sure iron is up to temperature,
test by touching iron to solder and see if it quickly melts.  Attach heat
sink to terminal between element and joint are to be soldered.  Clamp or
hold all parts to be soldered in such away that it won't move during the
soldering process, remember you'll be using two hands, one for the iron, one
for the solder.  Heat joint with iron, touch joint with solder, as soon as
the solder flows and fills the "ring" of the terminal, pull solder away then
iron.  Let joint cool before putzing around with it or trying to resolder if
you don't get it right.  Remember, too much heat to the joint and you're
screwed!

Remember, practice makes perfect, practice first on trashed stuff before
soldering on valuable goods.

Good luck,
Don D.


- ----- Original Message ----- 
From: "Robb Bingham" <robbingham@xxxxxxxxx>
To: <harp-l@xxxxxxxxxx>
Sent: Sunday, July 18, 2004 7:50 PM
Subject: CR Mics


>
> Mic Gurus [or even tinkerers]! Please help!?
>
> I've been collecting controlled reluctance elements
> [the kind that look just like CM elements but say CR
> on them] for a while and have recently discovered that
> you can ruin them when you get the lead too hot [while
> soldering the wires to them]. At least I assume that's
> what I did wrong. All I know is that they worked great
> before I connected the new wires to them and soldered
> them- to prevent a bad connection in future [or that
> was my hope].
>
> I assume that the whole lead gets too hot and melts
> it's connection loose, on the other/internal end- -
> BUT, when I peeled back the tape to see, I can not see
> where they WERE ever connected to any dang thing,
> other than a piece of plastic which, I assume holds it
> in place and lets it do it's reluctant magnetic thing.
> IS THERE ANY way to undo the harm I've done? Is one
> not supposed to solder them that close to the element
> [I've removed the plastic case to fit it in other
> shells]? I've been wiggling and prodding, but the
> sound is a quarter what it was. Is there anything I
> can do to salvage these puppies???
>
> Many thanks,
> Robb
>
>
>
>
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