[R-390] R-390A Filters

[Roy Morgan]

At 10:09 AM 7/6/2007, DW Holtman wrote:
>Hello,
>
>Are the mechanical filters used in the IF Deck Symmetrical, that is can 
>the signal be put in either end?

As I understand it, yes.  Folks may have tested that and report their 
experience.

The term "symmetrical" is also used to indicate that the skirt curve is 
similar on the upper and lower sides of the passband.  I think that Collins 
mechanical filters that were designed for SSB operation are not 
symmetrical. They may have steeper curves on the side that the carrier is 
to be on, and thus provide higher suppression of the carrier.  (In 
addition, the SSB filters may be designated with a carrier frequency not 
the center of the passband as part of the type number and specs.)

Roy




- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing
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