[R-390] IF Filter Disassembly

[n4buq at knology.net]

On Mon, 7 Aug 2006 15:38:43 EDT, Flowertime01 at wmconnect.com wrote :

> Mike,
> 
> Yes, I remember how to get an R390/A mechanical filter apart.
> I hope that is your question.
> 
> You can unsolder the leads to the cylinder and unbolt the mechanical 
filter 
> from
> the chassis. Watch for some more mail and the web page with the photos.
> 
> Once you have the filter out of the chassis, you hang the filter by its 
> chassis mount
> tabs and bolt holes from the ceiling (or a tree). You tie a long lead to 
the 
> electrical connection tabs on one end. 
> 
> Obtain suitable safety equipment and a letter from your mother or 
significant 
> other to proceed from here. I am not responsible when you burn your self.
> 
> You heat both ends of the cylinder sleeve to melt the solder. 
> You pull on the long wire you attached.
> When it gets hot enough on both ends of the cylinder to melt solder,
> the guts will slide out of the cylinder.
> 
> You can preheat and solder suck some of the solder out of the way first.
> 
> On a good day this works well.
> Just understand you are working down hill in a gravity well with molten 
> solder above your arm and hand while the other hand is busy with a 
flaming torch.
> 
> Long sleeves, good gloves, and safety glasses are all in order.
> 
> A small torch works better than a big torch.
> But any torch works better than a solder iron as it will get the whole 
mass 
> up to the critical temperature much neater than an electric iron.
> 
> The guts clean up and mostly can be repaired.
> Most common failure is a broken wire inside the filter.
> 
> Roger AI4NI

It seems like you could save yourself some time and just grab a hot 
soldering iron with your bare hands, couldn't you?

Seriously, it would seem that having the filter body above the heat source 
is not the best choice.  Couldn't you secure the body to something near the 
ground and pull the wire up as you heat the body (or even sideways would 
work)?

Barry - N4BUQ