[R-390] Collins mechanical filter - help with identification

[John Kolb]

F450 Z1C   USB filter 450 kHz cazrrier freq 2.7 kHz at 2 db,4.4 kHz
at 60 db 20 kohms source and load resistance, 30 pF resonating caps
4 db insersion loss. V case.

F450 Z2C   same as above, except LSB

F450 V60F   AM filter, 450 kHz 5.25 kHz @ 6 db, 23 kHz @ 60 db specified.
8 db insersion loss. V case. 
I have the plot of one on my web site which is probably much closer to
typical.  <http://www.jlkolb.cts.com/site/mfcurves.htm>


When receiving mechanical filters mounted on a board, it's always good
to trace out the circuitry around the filters to try to get an idea 
of how the filters are matched to the tubes or transistors. Information
on the frequency and bandwidth of filters is fairly widespread, but
information on the impedances required to properly match the filter
are rather rare.

John
http://www.jlkolb.cts.com



Joachim R Groeger wrote:

>Folks,
>
>I have salvaged three mechanical filter from a circuit board but cannot identify the filters themselves nor the equipment they came out of.
>
>Can anyone help me with the characteristics of these beasts?
>
>They are marked:
>
>F450 Z1C
>
>F450 Z2C
>
>F450 V60F
>
>Any help is greatly appreciated.
>
>73
>
>J R "Jo" Groeger
>G4XXW, DK3NG, EL0AA/MM
>
>
>  
>