[Elecraft] OT: Elecraft Relays for BC-Band Energy-Reject Filter

[N2EY at aol.com]

In a message dated 11/16/06 1:54:47 PM Eastern Standard Time, va7to at rac.ca 
writes:


> The 
> relays used by Elecraft (Omron G6HU-2) are DPDT and a single relay could 
> switch both input and output, but I am concerned that the isolation between 
> the input and output would be comprised by the proximity of the input and 
> output connections and contacts.

My guess is that the the isolation would be compromised, particularly where 
you need it most.

> I could also use one relay at the input side of the filter and another 
> relay 
> at the output side of the filter which should have better isolation.
> 

Two relays is definitely the way to go. Since the relays are DPDT, use one 
pole to switch each end from the filter input to a piece of coax bypassing the 
filter, and use the other pole to ground the center conductor of the bypass 
coax when the filter is selected. That way the coax has a harder time acting as a 
path around the filter.

73 de Jim, N2EY