[Elecraft] KX3 4 knobs and sea spray/salt corrosion

[Dominic Baines]

Hi,

In the last year I have operated a few times /P from the beach often 
with sea spray and recently twice on long ferry crossings of the North 
Sea (return operating was cut short though) and out on deck most things 
end up with a mist or film of sea spray on them and you will see the 
small white spots of salt when the water evaporates. I have noted at 
least two of the 4 knurled knobs on my KX3 are showing signs of 
corrosion and were becoming difficult to turn. I have cleaned the nut 
threads (both sides) and applied a very little copper grease to them I 
also washed the whole of the KX3 inside and out (part disassemble 
needed) using cotton buds and isopropal alcohol where any salt effects 
were obvious. The front bezel screws had kept 99.99% out from the 
display but I have had to remove that and clean it up a bit. I might put 
back with a fine bead of silicon sealant.

I have added a small copper braid flying lead between the two parts of 
the case and covered it with 'liquid rubber'.

The clam shell style unfortunately is not great if you operate in these 
environments as sand/salt does get in no matter how hard you try to 
protect it.

I do not immerse the radio in the sea but after a couple of weeks in 
this environment you will notice the effect. In the meantime antennas 
have had to have connectors remade etc. so it is not really a surprise.

Has anyone got an alternative to these knurled knobs that are a little 
bigger as it is very difficult to open the case wearing gloves? (you 
only need to if you are using the AA batteries which I tend not to if 
that wet) I had thought about swapping them for Ali versions or cutting 
slots in them for a screw driver. Anything like those lay flat butterfly 
nuts/ knobs you used to find on old military kit might suit better.

In definitely wet (i.e. raining) conditions the KX3 is used inside a 
tough see through plastic box (lock'n'lock) with leads passed through it 
with bathroom silicon sealant. I used to do this with my FT817 as well. 
Costs £5 from supermarket.

I wish the KX3 had a lock frequency function which would be useful when 
I have to do this, why is this still missing?

72

Dom
M1KTA