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[RFI] Phone RFI fixes - no ring, lower cost solutions?

To: <rfi@contesting.com>
Subject: [RFI] Phone RFI fixes - no ring, lower cost solutions?
From: Bob Wanderer <aa0cy@nwrain.com> (Bob Wanderer)
Date: Wed, 22 Dec 1999 09:28:38 -0800
A high pass filter will do nothing to an ingressed signal such
as 2 metres on cable channel 18 because they are on the same
frequency.  I am of course assuming that you're talking about
your 144 MHz signal.  If it's a harmonic, you need to put the
high pass filter on your ham coaxial cable obviously.

I would think Canada would have leakage requirements akin
to the FCC (20 microvolts/metre @ 3 metres OR no harmful
interference) because of possible problems with the aeronautical
band 108~138 MHz and cable television mid-band channels.

73,
Bob AA0CY

----------
From:  Pete Smith[SMTP:n4zr@contesting.com]
Sent:  Wednesday, December 22, 1999 6:12 AM
To:  Gorsline Family; rfi@contesting.com
Subject:  Re: [RFI] Phone RFI fixes - no ring, lower cost solutions?


At 08:47 PM 12/21/1999 -0500, Gorsline Family wrote:
>
>Background  - roof mounted F12 C3S, 100 wts in downtown row house.  Not
>on air much - casual DXer (310 DXCC).  Neighbours have telephone RFI, so
>do I.  TVI as well - mostly channel 3 and videotapes - everyone on cable
>with VCRs.  Decided it was time to fix things up - neighbours tolerant
>and I get off air (even when in the pile for a new one) when asked.
>But, the countries are getting a bit harder and teenagers expect
>continuous telephone availability.
>
>I eliminated my telephone RFI by grounding all spare conductors and
>putting .001 caps from each side to ground at the entrance, plus and 10
>#43 beads on one phone cord.  Problem is that the long distance ring
>(Morse D) wouldn't fire and wouldn't trigger voice mail - local single
>ring OK.  Removed caps, ring now is OK and of course, RFI is back.
>Ideally, I'd  like to give the neighbours the plug-in modular filters  -
>enough for every phone (say 5/house).  At $30-40 CDN each, is there a
>less expensive way?

K-Com also sells the filter components in a hard-wire form for
significantly less.
Don't know if you want do surgery on the neighbors' phones, though.  They
might give you a significant price-break on a quantity of the modular units.

>
>For the TVI - is there a high pass coax filter (ideally male-female to
>put in the CATV line)?  Yes, lots of cable ingress/egress - 2m and CATV
>channel 18, pagers on channel 17 and 21.

Authorities here are quite fierce on cable companies about leakage.  Does
the Canadian counterpart have anything to say?

Frequently, local in-house leakage results from splitters with
un-terminated ports, poorly-installed connectors, etc.  Why not try to
clean up your own house first, as a guinea pig.  ICE makes a good high-pass
for coaxial systems, I'm told.
 

73,  Pete N4ZR

Don't forget to update your entry in the contest station database
http://206.102.70.3/search.htm


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