On Wed, Feb 14, 2024 at 02:30 AM, Donald S Brant Jr wrote:
On Tue, Feb 13, 2024 at 02:43 PM, Adrian YO3GFH wrote:
In my previous post, I've mentioned very fine grained (800 grit) sandpaper used for shining guitar frets, that's the one you should use.
Or one could use the right tool for the job, a contact burnisher:??
I wonder whether the issue will return after cleaning.? A problem might be that too little current is being handled by the contacts, there is a minimum so-called "wetting current" required to break through contact film/oxidation and allow a low-resistance contact:??
Special contact materials and mechanical configurations are used when switching very low currents, to avoid this issue.? Mercury-wetted contacts are an example.
I do not have a schematic handy but I winder if there is a pullup resistor which might be changed to a lower value to put more current through the key contacts.??
73, Don N2VGU
Now I realise I wrote 800 instead of 8000.. I must've been hungry when I posted :-) so it's 8000 grit sandpaper, I just checked. Need to change my glasses :-)
That contact burnisher looks nice, but I haven't seen any mention of grit - judging from the picture, looks a bit coarse but, in all fairness, it's not a hi res pic so might be artefacts.
I think you make a good point with the minimum current!
Regards,
YO3GFH
op. Adrian
