[rec.ham-radio] RFI on telephone

nagle@well.UUCP (John Nagle) (09/18/89)

      I've been receiving two local AM broadcast stations on my
Western Electric Model 600 telephone.  I fixed the problem by 
putting a 1000pF capacitor across two terminals within the phone
that seemed to work.  (Putting it across the phone line didn't help,
in fact, a dead short across the phone line turned the phone into a
good radio!)  This seems a hokey solution to the problem.  Is there
a more respectable one?

				John Nagle

waters@darla.sps.mot.com (Strawberry Jammer) (09/18/89)

In article <13681@well.UUCP> nagle@well.UUCP (John Nagle) writes:
}
}      I've been receiving two local AM broadcast stations on my
}Western Electric Model 600 telephone.  I fixed the problem by 
}putting a 1000pF capacitor across two terminals within the phone
}that seemed to work.  (Putting it across the phone line didn't help,
}in fact, a dead short across the phone line turned the phone into a
}good radio!)  This seems a hokey solution to the problem.  Is there
}a more respectable one?

Considering that the problem comes from audio level setting diodes within the
telephone set itself I would hardly call your solution "hokey". The only
"hokey" thing about it is a manufacturer who blithely assumes that RFI is
rare just because it was 50 years ago!

So long as the fix and the phone work I would just go on using it! You might
try ferrite beads on the wires to the phone as well if the capacitor isn't
enough too.


           *Mike Waters    AA4MW/7  waters@dover.sps.mot.com *
Take it easy, we're in a hurry.

rsd@sei.cmu.edu (Richard S D'Ippolito) (09/19/89)

In article <13681@well.UUCP> John Nagle asks:

         I've been receiving two local AM broadcast stations on my
   Western Electric Model 600 telephone.  I fixed the problem by 
   putting a 1000pF capacitor across two terminals within the phone
   that seemed to work.  (Putting it across the phone line didn't help,
   in fact, a dead short across the phone line turned the phone into a
   good radio!)  This seems a hokey solution to the problem.  Is there
   a more respectable one?


Hmmm, a fifty-cent solution that works -- what's so unrespectable about that?


Rich
-- 
It is not the possible that determines what to hope for --   
it is hope that determines what is possible.
Richard J. Oman                                               rsd@sei.cmu.edu
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lsheldon@cup.portal.com (Laurence Larry Sheldon) (09/19/89)

Two general areas to check out--


Corroded, loose, or missing ground connection 

Corroded, or loose other connections.

(That makes up one area)

Noisy carbons.  (Find the protector--where the teloc wires transition
to the house wire.  Unless theprotector is very old, it will have
what appear to be two large brass screws.  You will discover that you
can remove them without changing any thing.  If you remove them and
the radio goes away--the carbons you now have in your hand nead to
be replaced.  Put them back and complain to the telco.