[R-390] Filters

[MICHAEL TALLENT]

There is a small magnetic wire probably spot welded to the center on each 
end disk and goes through the center of the coil to convert the magnetic 
field produced by the coil into mechanical movement to form an acoustical 
wave that travels through the disks and causes the small wire at the other 
end to vibrate and then generate a small signal into the coil at the 
"output" end of the filter.
http://en.wikipedia.org/wiki/File:Mechanical_filter_with_disk_flexual_resonators.svg

Mike T  W6MXV

----- Original Message ----- 
From: "k2cby" <k2cby at optonline.net>
To: "R-390 Mailman" <R-390 at Mailman.qth.net>
Sent: Saturday, February 16, 2013 5:48 PM
Subject: [R-390] Filters


>I took a hard look at the photos, and it seems to me that all of the
> magnetic coupling wires are in place.
>
>
>
> While there are fine wires in the coils, the coupling wires that everyone
> seems to be referring to are on the perimeter of the filter discs and 
> appear
> to be at lease 0.5 mm (the lead in a mechanical pencil)  or about #20 awg.
>
>
>
> Whatever is described as a "hair thin wire" has to have come from the 
> coils,
> not the resonators, unless is just an artifact that crept in from the 
> bench
> during manufacture.
>
>
>
> Miles B. Anderson, K2CBY
> 16 Round Pond Lane
> Sag Harbor, NY 11963
> Tel.: (631) 725-4400
>
> Fax.: (631) 725-2223
> e-mail: k2cby at optonline.net
>
>