[AMPS] Switches

Tom Rauch W8JI@contesting.com
Thu, 12 Oct 2000 13:32:34 -0400


> If the rotor is not connected to anything, the spacing between the rotor
> and the contact is unimportant.  By using adjacent contacts on the wafer
> as the switch - with the rotor simply acting as a connecting contact, the
> voltage rating would be doubled.  It requires a bit of thought

Look at the front wafer of the AL-80B. That's the wafer that 
switches in the 160 padding cap.

It has exactly that configuration.

That switch is still limited by rotor to contact breakdown voltage. 
The arc path is from contact to rotor, and back to the other contact.

Voltage doesn't double at radio frequencies because of 
capacitance between the rotor and everything around the rotor.

The "anti-corona" washer in the AL80 series helps improve voltage 
distribution by distributing the field around the highest voltage 
contact and rotor more evenly.

If you remove it, voltage breakdown drops about 30%.    
 
> In reviewing switch wafers, I observe that the distance between the spacer
> and  a few of the terminals is the closest spacing.  That spacing seems to
> be much closer than the contact to rotor distance.

Not on the RSC switches. Look at the measurements I posted. 
 

73, Tom W8JI
w8ji@contesting.com

--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com