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Gold Medal Software - Volume 3 (Gold Medal) (1994).iso
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FILE4.004
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1994-04-01
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3KB
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46 lines
TVI REVISITED
Joe Valente VE3VDK
This article is a continuation to the previous piece that appeared in
Ham On Disk Issue #1. Some people have had complaints that they are
receiving interference on their telephones. I have also had a personal
experience in this regard. Through my investigation, I found that the phone
that I was breaking in on was not a Bell Canada phone, but an after market
phone that you can buy for $19.95 at any of the big carry anything stores.
I also found that if this phone was replaced with a NORTHERN TELECOM phone,
that problem no longer existed. The solution to my problem was easy, I
replaced the phone. It wasn't so easy with my neighbour's phone, she also
had one of these so called cheap after market phones. She was not as
willing to replace her phone with the old traditional Northern Telecom
phone that we all grew to love over the years. Needless-to-say, the station
I am using has all the necessary grounds, the low pass and high pass
filters in line. The equipment being brand new was also checked on a
spectrum analyzer and found to be in spec. In frustration, I went to the
Bell Centre, and explained my problem to the girl at the counter. When I
got through, she excused herself for a moment and went to the back room.
When she came back, she gave me a hand full of telephone line rf choke
filters. She then said if they didn't help, I would have to arrange a
service call with a technician. She also was kind enough to say no charge
when I asked how much I wed for the filters. Thanks Bell Canada. I
installed the said filters in the neighbour's home some time ago now and
she has of yet to complain that the problem is back.
I have read articles of people having similar problems and having to
install ferrite beads on the leads inside these so called "phones". I was
glad that I didn't have to go that far to solve my problem. TVI is very
peculiar, it has no boundaries. Many times you don't know you have a
problem until someone comes to you with the complaint. I was watching T.V.
the other day in the radio room and I thought I would turn on the short
wave receiver. As I tuned in the 14 MHZ range, I started to see some weird
lines on the screen. This isn't supposed to happen from a receiver. Thinking
about it for a bit, I concluded that as I tuned the radio the IF frequency
must have "beat" with the TV's IF to cause the problem. This did not happen
on all the channels of the TV set. If you have TVI and tried everything to
get rid of it, the next thing to try is lowering your transmitting power to
as much as just enough to get you on-line. Sometimes re-organizing your
radio time to off peak hours, ie. middle of the night or early morning,
may be the solution that works.
GOOD LUCK ...... Joe Valente VE3VDK