First, I don't like to use UHF connectors at all; N connectors are easier to
install and more trouble-free over the long haul. But in the few cases where
PL-259s are unavoidable, I *do* use a soldering gun, but without the tip. I
made up two little copper spuds that stick out of both tips of the gun, but
don't touch each other. When I jam the gun against the connector barrel, the
barrel completes the circuit, making a simple and very repeatable resistance
soldering rig.
I can't claim credit for this idea; it has probably appeared in Hints and
Kinks several times over the last 40 years.
geo, n4ua
> -----Original Message-----
> From: Steve Katz [mailto:stevek@jmr.com]
> Sent: Tuesday, February 04, 2003 5:59 PM
> To: 'Paul Womble'; 'towertalk@contesting.com'
> Subject: RE: [CQ-Contest] RE: [TowerTalk] coax cables
>
>
> Hi Paul,
>
> It doesn't have much to do with "wattage." It has to do with
> thermal mass.
>
> A large soldering IRON, the type with a 1/2" wide or larger
> chisel tip made
> of copperclad iron and attached to a huge heating element
> barrel that weighs
> a couple of pounds, has a large thermal mass. So large that when it
> transfers its heat to the barrel of a PL-259, the soldering iron tip
> temperature doesn't even change, because its thermal mass is
> huge compared
> with the small thermal mass of the connector.
>
> A soldering GUN, on the other hand, regardless of its
> "wattage" rating, has
> a tiny soldering tip, about an ounce of pure copper, and
> that's all it's
> got. Copper is very thermally conductive, so it heats very
> rapidly. Which
> means it also cools off very rapidly. Which means that when
> its tip is
> applied to the connector body, the connector, having much
> larger thermal
> mass than the soldering gun's tip, sucks all the heat out of
> the tip and the
> tip temperature immediately drops below soldering
> temperature, so you have
> to keep the trigger pulled while it heats up again.
>
> All this time, you're pouring heat into the connector body as
> it slowly gets
> hotter, and hotter, and hotter, for quite a while. While
> that's occurring,
> the cable dielectric is melting.
>
> Ugh.
>
> A good IRON, on the other hand, transfers enormous heat very
> quickly without
> cooling down and thus the connector body can be soldered
> within a couple of
> seconds. And then the iron can be removed so the connector can begin
> cooling off before the cable dielectric melts.
>
> And that's about it.
>
> WB2WIK/6
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