[FoxHunt] feedthrough capacitors/EMI filters

[Michael J. Miller]

Besides the various commercial sources, old TV tuners are a good source for
small feedthrus.  Also ferrite beads and small chokes.  If you use both, you'll
get much more attenuation at VHF.  Small values of C and L won't bother the
slow digital switcher signals, or the analog ones to the radio.

73,

Mike
WB6TMH

Joe Mayenschein wrote:

> I use the ones from Hamtronics all the time for all my projects.
>
> Joe
>
> Matthew Francey wrote:
>
> > I have an old doppler project that I am resurrecting.  It was based on a
> > 68HC11, and was successfully implemented and used on a few hunts in 1994
> > and 1995).  At the time, someone gave me a few feedthrough capacitors
> > in an effort to squelch the compu-shriek from weasling its way from the
> > microcontroller, into the antenna switcher, and then into the radio.
> >
> > I'm currently looking for a bunch of feedthrough capacitors, or even
> > better (based on some grepping's of the net) EMI filters.  They have to
> > be fairly small (~1cm diameter), and should be low-pass as the signals
> > are TTL-level digial control lines and vary <1kHz.  While they all have
> > to conduct DC, most of them don't need to carry signifigant currents,
> > though at least one will have to take maybe a hundred milliamps (if that)
> > at +12V: everything needs a power supply.
> >
> > Can someone recommend a part+source?  Thanks!
> > _______________________________________________
> > FoxHunt mailing list
> > FoxHunt@mailman.qth.net
> > http://mailman.qth.net/mailman/listinfo/foxhunt
>
> _______________________________________________
> FoxHunt mailing list
> FoxHunt@mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/foxhunt