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SMT is not that bad ...
Pre-heating the board first is a
good move ..pre heater ? , well
domestic IRON is a nice size flat plate , tem controlled
as well .. synthetics ? cotton may be too hot
(no steam of course .. that comes later at the
testing stage)
small butane blow lamp works
nicely ..two soldering irons at once for
simple components ...
the big chips will go
with 1 pass of the iron on each side ...1 pass !!
sticky solder flux paste ..
lots of solder wick ..
components will 'suck' down to the
board once the solder is melted at each end ... and as
there are no plated holes , physical board damage
is much reduced ..if it all go's wrong , clean
the board up and start again
>>> Start practicing now before you're forced to.
>>> Lots of old PC boards and
cards about to play with as well , remove and
replace the components - minimal solder is needed as
the pad area is quite big
G ..
Sent: Wednesday, December 29, 2010 11:52 PM
Subject: Re: LF: DK7FC's VLF Active Antenna
It won't be long before leaded components become unavailable.
Certainly the useful modern ones that actually do teh job that's
wanted. I've compared availability and prices in the Farnell
catalogue recently (having just got the almost cubic shaped printed version
:-) and leaded components are just more expensive and less available
that SMT equivalent. And the bulk ordering quantities
available on many of them make ordering less than 100 off of some of
the more popular ones just a waste of money.
Constructors really will have to start getting used to using SMT devices
are their first choice every time. Start practicing now before you're
forced to.
Andy
been using SMT components for preference for something like 15 years
now.
2010/12/29 Stefan Schäfer <[email protected]>
Hi Ken, I have not tested other
JFETs so far. Is it just because of the SMD housing? I don't use a SMD PCB but
a "free air" soldering. So if this is the problem, just solder the FETs legs
directly on the next part, e.g. solder the drain directly on the 390 Ohm
resistor. Attached you find a picture that shows how my current used VLF
grabber antenna looks inside. Don't be shocked ;-) If you anyway want
an alternative, the J310 or the (2SK170) should be possible. There are
some parameters like the noise and the gain and the input capacitance which
are affecting the performance but this is all not so critical on
VLF. 73, Stefan/DK7FC Am 29.12.2010 17:58, schrieb Ken:
Stefan.
Could you please recommend an equivalent to to
BF862 which is not Surface Mount for use in this circuit.
73s
Ken
M0KHW
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