[Elecraft] Toroid enamel covering

[Don Wilhelm]

You can (and should) tin the leads all the way up to the core.  The cores
are not conductive (although the ferrite cores do have a high resistance),
so it will not short out.  The thing to be careful of is not to allow two
adjacent turns to short together.

I suspect you are not using enough heat to melt the enamel.  It is vital
that you get the leads stripped and well tinned - your K2 will not work well
if you are careless about tinning the leads.  Toroid Lead Tinning and
soldering are the two most important items in construction of your kit.
Practice until you can make a clean tinned lead - your kit has extra wire.

I suggest the 'solder blob' method for tinning the toroid leads.  Using a
soldering iron with a wide chisel type tip helps because it can hold a
larger blob of solder.  Run the iron temperature at 750 degrees or so (I use
800 degrees - the extra heat helps), melt a pool of solder on the tip and
initialy hold the end of the wire still in the solder pool - when the enamel
begins to make smoke wisps, the enamel is melting - touch a small bit more
solder to the wire (which adds a bit of fresh flux at the solder/wire
junction) and begin to move the wire slowly through the solder pool, you
will be rewarded with a clean stripped and tinned lead.

It helps to secure the soldering iron to the workbench (I just lay a heavy
tool on the handle) and manipulate the toroid and solder with your (now)
free hands.  I have problems if I try holding the toroid and moving the
iron - YMMV, but try securing the soldering iron and see if it helps you.

73,
Don W3FPR

> -----Original Message-----
>
>   I am curious about the removal of toroid wire enamel covering
> material in preparation for winding. Is it essential that bare
> wire not touch the toroid ring?
>
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