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Old November 5th 05, 05:34 PM
Ian White G/GM3SEK
 
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Default Problem with soldering gun

Steve Nosko wrote:
Nope. I got it, but I see your point. The issue I was thinking of was the
fact that the hot air "pre-heat" will still take longer than a high
heat-capacity tip, thus allowing more opportunity (time) for the dielectric
to soften and deform if it isn't held well, without stress applied. I think
RG-8 size is probably less of a problem. RG-58 tends to easily allow the
center conductor to travel if given the opportunity.

It doesn't seem to be a problem with either size of cable, largely
because the dielectric doesn't get hot enough to melt and become runny,
and also because the center conductor isn't trying to move off-center
anyway.

My hot plate also only "warms" the ceramic so, when touched with the iron
for the heat-to-solder phase, it doesn't do that almost imperceptible
TINK! from the almost invisible crack across the ceramic due to an all to
large temp gradient.

Ah, now I see what you're using it for.

How long do you take in the warming phase before doing the actual
heat-to-solder phase?

About 10-20 seconds with a 2kW hot-air gun.... but that obviously
depends on a lot of other variables, particularly the power of the
electric iron to follow.

My worry with many of the "big iron" methods is that it's very hard to
be sure you have a good solder joint, all the way down the sides of the
hole. More often, I suspect it makes a good joint to the braid but a
cold joint to the sides of the hole. This may look OK, but the plug of
solder may eventually work loose in the hole.


--
73 from Ian G/GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek