[R-390] Testing Collins Mechanical filters:

[kc2fxe at gmail.com]

Hello All:
yea if someone offers a filter repair service i have a 4kc filter with a  
inter. shot to the case..
John kc2fxe

On Apr 24, 2009 5:12pm, Dennis Wade <sacramento.cyclist at gmail.com> wrote:
> Does anyone offer a filter rebuilding service? I have a 16, 8 and

> possibly a 4 kc filters in need of repair.





> Dennis





> On Fri, Apr 24, 2009 at 1:47 PM, Tim Shoppa tshoppa at wmata.com> wrote:

> > KIORQ writes:

> >> But the audio is not very loud.

> >> Anyone have any ideas?

> >

> > Ohmmeter tests:

> >

> > Across input and output coils of each filter, it should

> > be 50 to 100 ohms. (Web says 50 to 60 ohms, my

> > memory says closer to 100 ohms...). This is the

> > DC resistance of the transducer coil.

> >

> > Between the signal pins and can should be

> > very very high resistance, bigger than megohms.

> > If it's leaky at the megohm level AGC action will

> > reduce the gain.

> >

> > If there is leakage but only between one end and

> > ground, it may be possible to isolate the filter can

> > from ground.

> >

> > Standard reference on rebuilding filters:  
> http://www.delphelectronics.co.uk/filter390a/

> >

> > I kinda wish that I would get laid off of my job

> > so that I could have time to fix my bad mechanical filters

> > (and all the other old radios laying about the shack.)

> > As it is others are getting laid off and I have to work extra

> > hard to pick up the slack.

> >

> > Tim N3QE

> >

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> --

> Dennis L. Wade

> KG6ZI

> Carmichael, CA

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