[R-390] Filter testing

[Norman Ryan via R-390]

Hmmm, test with no power applied?  Okkkkay...

In that case the quickest way, IMO, would be a simple continuity test with an ohmmeter.  If you read roughly 50 ohms on each coil and close to infinity from the terminals to ground, chances are good that the filter under test is OK.


Bear in mind you have to switch around the bandwidth control to get true readings.

As far as I can tell, the next test is to put the IF deck in the receiver, power it up and check alignment per the manual.  Alignment often isn't needed unless you suspect the slugs and trimmer caps have been messed with.

Replace C553 with a high quality film foil cap such as has been suggested recently by Charles.

Good luck,
Norman



On Friday, August 8, 2014 5:31 PM, rbethman <rbethman at comcast.net> wrote:
 

>
>
>All,
>
>With an IF deck with no power applied, what would be a test set up, 
>filters in place and wired, that would indicate that they can/will pass 
>a signal?
>
>I have multiple signal generators, and a TEK 5440 scope.
>
>Would setting to 455Kc on the sig gen, first looked at and synced with 
>the scope, then applied to each filter input, and look at the output do 
>this?
>
>I'd also ask if it really matters which direction the signal is applied?
>
>Bob -  N0DGN
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