[Amps] copper or silver in tank circuit?

G3rzp@aol.com G3rzp at aol.com
Thu Jun 16 09:17:23 EDT 2005


I think the idea is that silver oxide and silver sulphide are conductors,  
while copper oxide isn't. So the coil Q stays up after the atmosphere has been  
at work on it.
 
Wheter or not you can tell the difference at HF is another matter.
 
For a roller coaster, it should be worthwhile. At an IEE Conference in  1963, 
a description of a 80kW output HF tx says that the coil is made of tubing  
with air blown through it. The coil is rhodium plated to minimise the effects of 
 oxidation, and the roller contact is 90%silver 10%graphite. This kept the  
contact temperature down to 30 C even under continuous transmission (  FSK).
 
A 30kW output tx by another manufacturer is described in the IEE conference  
proceedings: that had a plain copper tube tank coil that used swinging arms to 
 tap on to it, driven by insulating cams.
 
73
 
Peter G3RZP


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