[TowerTalk] Tarnished connectors

[jimlux]

On 8/20/19 4:16 PM, Wes wrote:
> I agree.  Also when going to gold, most  (all)  commercial plating shops 
> will put down a nickle barrier on the base metal then plate with gold.  
> If the gold is too thin and the skin depth too deep, your gold surface 
> is RF wise, actually nickle.
> 
> I once designed a test station for X-band IMPATT diodes and we built the 
> prototype 1/4-height waveguide oscillator in-house and did our own 
> plating in the model shop.  Since we were going to calibrate and supply 
> a number of these to our IMPATT vendors, we had the design replicated 
> and sent the plating job to an outside vendor.  If you simply specify 
> minimum total plating thickness, you get lots of nickle and a flash of 
> gold.  It took lots of hours to figure out why we weren't getting any 
> power output.
> 


there's an excellent description of this on microwaves101.com in the 
multitude of pages on skin effect.