[R-390] Filter pins

[John Kolb]

Either end of the R-390A F455N- series filters can be the input
and either the output. The filters have 3 pins at each end, 1 gnd
and 2 pins for the coil. Either of the two coil pins at each
end can be the RF ground side.

John

On Thu, 5 Feb 2004, Dan Merz wrote:

> Hi,  I'm trying to use a NIB 2 khz mechanical filter of 390a type as a
> substitute for the single ended type Collins filter that went into a
> nine pin socket in my Mackay tube radio.  I have a couple of questions.
> Has anyone accomplished this or a similar adaption?  I know the input is
> the upper end but I'm wondering whether the two pins on each end are
> "equal" with respect to ground - can I put the input connections either
> way on them? Similarly can I put the output connections either way on
> the lower end?  There will probably be other problems,  like getting the
> leads from the top to bottom to behave ok.  My first inclination was to
> try to make it a plug-in unit with 9 pins but I'm starting to think
> maybe I should just pull the socket out and mount the filter in the
> hole,  much as it's mounted in a 390a,  and feed the top two leads thru
> added holes in the chassis.  Any ideas?  thanks,  Dan.
>
>
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