[time-nuts] FRS-C TTL / sine outboard filter question

Mike S mikes at flatsurface.com
Wed Jun 23 21:12:20 UTC 2010


At 04:19 PM 6/23/2010, Leigh L. Klotz, Jr. WA5ZNU wrote...

>If you have these values we can document the rest of this process in 
>one
>place.
>
>10 MHz sine                 TTL
>L1   ?.? uH                 L1 OMIT
>L2   1? uH                  Replace with R23 130 OHM 1 WATT
>R16  ?10 OHM NOM            100 OHM NOM
>R17  1.0K                   274 OHM NOM 1/4W
>R18  1.0K                   OMIT
>C8   47pF NOM               JUMPER
>C9   6800pf NOM             0.47 uF NOM
>C16  0.1uF [1uF: see above] JUMPER
>C17  240pF NOM NP0          OMIT
>                             INSTALL JUMPER A-0


Here are the values I used.

L1 6.8 uH
L2 15 uH
R16 910 Ohm nom
R17 1.0K nom
R18 1.0K
C8 47 pF nom
C9 6800 pF nom
C16 0.1 uF (but 1.0 uF provides much cleaner signal)
C17 240 pF NPO nom 





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