Recent cures here........
The S-video cable from DirecTV box to TV gave bad TVI.
Went back to YRW cable. Can't notice enough difference in quality to bother
with further efforts.
Low band audio and slight TVI traced to bad connection on ground side of
R-audio cable. Could wiggle cable with no change in TV audio but TVI would go
away.
Clip lead grounded DirecTV and DVD boxes together. Helps on some bands, makes
worse on others.
Disconnected outdoor antenna after getting local channels from DirecTV.
New DSL modem cured 160m crashes, but now high bands crash it, beads one
everything.
You can't win
----- Original Message ----
From: "rfi-request@contesting.com" <rfi-request@contesting.com>
To: rfi@contesting.com
Sent: Wednesday, February 13, 2008 9:00:18 AM
Subject: RFI Digest, Vol 62, Issue 6
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When replying, please edit your Subject line so it is more specific
than "Re: Contents of RFI digest..."
Today's Topics:
1. Re: TV RFI - an update (rrath@charter.net)
2. Re: TV RFI - an update (Dave Hachadorian)
3. Re: TV RFI - an update (Jim Brown)
4. Re: TV RFI - an update (N3XX - Tim Heger)
5. Re: TV RFI - an update (Jim Brown)
6. Re: TV RFI - an update (dgsvetan@rockwellcollins.com)
----------------------------------------------------------------------
Message: 1
Date: Tue, 12 Feb 2008 18:01:49 -0800
From: rrath@charter.net
Subject: Re: [RFI] TV RFI - an update
To: rfi@contesting.com
Message-ID: <47B1DF0D.31596.61EE30@rrath.charter.net>
Content-Type: text/plain; charset=US-ASCII
Here is an update to my TVI:
Well my wife bought some snap on beads - 43 mix - and I put all 5 of them
on the power cord. Bought a High Pass filter, put it in-line; this all is put
on
the VCR. Reason for the VCR and not the TV, the VCR is receiving the TVI
and sending it to the TV. VCR on we get massive TVI. VCR off hardly any,
but some.
No change. Blaring SSB coming thru the TV speaker and lines wiping out
the picture.
I rapped the VCR with aluminium foil with all the other items still in place.
No change. Blaring SSB coming thru the TV speaker and lines wiping out
the picture.
I then put the snap on beads on TV, after removing them from the VCR.
No change. Blaring SSB coming thru the TV speaker and lines wiping out
the picture.
I do have 6 torroids coming. I will rap the power cord for both the TV and
VCR and rap the 75 ohm antenna cable. That will leave three torroids left.
Might have to add two torroids to the TV, VCR and the cable line.
Will let you know how things turn out.
Rod
------------------------------
Message: 2
Date: Wed, 13 Feb 2008 03:41:49 -0000
From: "Dave Hachadorian" <K6LL@ARRL.net>
Subject: Re: [RFI] TV RFI - an update
To: "RFI Reflector" <rfi@contesting.com>
Message-ID: <009901c86df2$7eeaf620$0202a8c0@newegg>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
So you have the catv hooked up to RF IN on the VCR and RF
OUT from the VCR goes to the TV?
Maybe you could just try some alternative hookups:
1. Switch the VCR RF output from channel 3 to channel 4
(there's a switch on the back).
2. Hook the catv directly to the TV & see if it's clean.
3. Hook VCR RF INPUT to catv in parallel with the TV through
a splitter, then take VCR composite video (RCA jack) and
stereo audio to an aux input on the TV. Even better, take
SVHS video from the VCR to the TV.
Sometimes simple measures like these can sidestep a whole
interference issue.
Dave Hachadorian, K6LL
Yuma, AZ
----- Original Message -----
From: <rrath@charter.net>
To: <rfi@contesting.com>
Sent: Wednesday, February 13, 2008 2:01 AM
Subject: Re: [RFI] TV RFI - an update
> Here is an update to my TVI:
>
> Well my wife bought some snap on beads - 43 mix - and I
> put all 5 of them
> on the power cord. Bought a High Pass filter, put it
> in-line; this all is put on
> the VCR. Reason for the VCR and not the TV, the VCR is
> receiving the TVI
> and sending it to the TV. VCR on we get massive TVI. VCR
> off hardly any,
> but some.
>
> No change. Blaring SSB coming thru the TV speaker and
> lines wiping out
> the picture.
>
> I rapped the VCR with aluminium foil with all the other
> items still in place.
>
> No change. Blaring SSB coming thru the TV speaker and
> lines wiping out
> the picture.
>
> I then put the snap on beads on TV, after removing them
> from the VCR.
>
> No change. Blaring SSB coming thru the TV speaker and
> lines wiping out
> the picture.
>
> I do have 6 torroids coming. I will rap the power cord for
> both the TV and
> VCR and rap the 75 ohm antenna cable. That will leave
> three torroids left.
> Might have to add two torroids to the TV, VCR and the
> cable line.
>
> Will let you know how things turn out.
>
> Rod
>
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
------------------------------
Message: 3
Date: Tue, 12 Feb 2008 20:28:28 -0800
From: "Jim Brown" <jim@audiosystemsgroup.com>
Subject: Re: [RFI] TV RFI - an update
To: "RFI Reflector" <rfi@contesting.com>
Message-ID: <20080213042834.E580457CC6@gw1.nlenet.net>
Content-Type: text/plain; charset="us-ascii"
On Wed, 13 Feb 2008 03:41:49 -0000, Dave Hachadorian wrote:
>Maybe you could just try some alternative hookups:
You may be right, but I doubt it.
In other words, it's far more likely to be common mode current
lighting up a pin 1 problem.
If the transmit frequency is 28 MHz or 50 MHz (unlikely nowadays),
changing between Ch 3 and 4 is more likely to do something. FWIW,
in all of this correspondence, I have not seen transmit
frequencies mentioned.
BUT:I have seen individual clamp-on ferrite beads mentioned. A
string of individual beads, even a dozen of them, provides FAR TOO
LITTLE IMPEDANCE below 50 MHz to make a dent in RFI, even if the
RF is being coupled on the cable that they are on (remember, we
must add enough impedance to reduce the current), and the lower
the frequency, the less they will do. We must use multiple turns
around a #43 (at least six) to begin to make a dent in RFI at
upper HP (20, 15, 10M) twice that number for 40 and 75 (and you'd
better be using a #31 toroid on 75/80 or 160).
Again, I remind everyone to study the part in my tutorial about
what I call "threshold effect" and then study the measured data
for various chokes.
73,
Jim Brown K9YC
------------------------------
Message: 4
Date: Wed, 13 Feb 2008 03:18:35 -0500
From: "N3XX - Tim Heger" <n3xx@charter.net>
Subject: Re: [RFI] TV RFI - an update
To: <rfi@contesting.com>
Message-ID: <000501c86e19$080210d0$6601a8c0@n3xx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I would check out the connectors installed on all the cables in the house,
especially those in the wall behind any wall plate. Many times contractors
doing cable installations will install the connectors improperly, making no
shield connection at all. Also be sure to get rid of any twist on or crimp
on connectors, and replace with snap-n-seal connectors. If using the 6 foot
jumper cable that came with the VCR to connect it to the TV, get rid of it
and replace with a good quality cable - those cables are junk.
GL & 73,
Tim - N3XX
----- Original Message -----
From: "Dave Hachadorian" <K6LL@ARRL.net>
To: "RFI Reflector" <rfi@contesting.com>
Sent: Tuesday, February 12, 2008 10:41 PM
Subject: Re: [RFI] TV RFI - an update
> So you have the catv hooked up to RF IN on the VCR and RF
> OUT from the VCR goes to the TV?
>
> Maybe you could just try some alternative hookups:
>
> 1. Switch the VCR RF output from channel 3 to channel 4
> (there's a switch on the back).
>
> 2. Hook the catv directly to the TV & see if it's clean.
>
> 3. Hook VCR RF INPUT to catv in parallel with the TV through
> a splitter, then take VCR composite video (RCA jack) and
> stereo audio to an aux input on the TV. Even better, take
> SVHS video from the VCR to the TV.
>
> Sometimes simple measures like these can sidestep a whole
> interference issue.
>
> Dave Hachadorian, K6LL
> Yuma, AZ
>
>
>
> ----- Original Message -----
> From: <rrath@charter.net>
> To: <rfi@contesting.com>
> Sent: Wednesday, February 13, 2008 2:01 AM
> Subject: Re: [RFI] TV RFI - an update
>
>
>> Here is an update to my TVI:
>>
>> Well my wife bought some snap on beads - 43 mix - and I
>> put all 5 of them
>> on the power cord. Bought a High Pass filter, put it
>> in-line; this all is put on
>> the VCR. Reason for the VCR and not the TV, the VCR is
>> receiving the TVI
>> and sending it to the TV. VCR on we get massive TVI. VCR
>> off hardly any,
>> but some.
>>
>> No change. Blaring SSB coming thru the TV speaker and
>> lines wiping out
>> the picture.
>>
>> I rapped the VCR with aluminium foil with all the other
>> items still in place.
>>
>> No change. Blaring SSB coming thru the TV speaker and
>> lines wiping out
>> the picture.
>>
>> I then put the snap on beads on TV, after removing them
>> from the VCR.
>>
>> No change. Blaring SSB coming thru the TV speaker and
>> lines wiping out
>> the picture.
>>
>> I do have 6 torroids coming. I will rap the power cord for
>> both the TV and
>> VCR and rap the 75 ohm antenna cable. That will leave
>> three torroids left.
>> Might have to add two torroids to the TV, VCR and the
>> cable line.
>>
>> Will let you know how things turn out.
>>
>> Rod
>>
>> _______________________________________________
>> RFI mailing list
>> RFI@contesting.com
>> http://lists.contesting.com/mailman/listinfo/rfi
>
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
------------------------------
Message: 5
Date: Wed, 13 Feb 2008 07:35:34 -0800
From: "Jim Brown" <jim@audiosystemsgroup.com>
Subject: Re: [RFI] TV RFI - an update
To: "rfi@contesting.com" <rfi@contesting.com>
Message-ID: <20080213153541.487C957E22@gw1.nlenet.net>
Content-Type: text/plain; charset="us-ascii"
On Wed, 13 Feb 2008 03:18:35 -0500, N3XX - Tim Heger wrote:
>I would check out the connectors installed on all the cables in the house,
>especially those in the wall behind any wall plate. Many times contractors
>doing cable installations will install the connectors improperly, making no
>shield connection at all. Also be sure to get rid of any twist on or crimp
>on connectors, and replace with snap-n-seal connectors. If using the 6 foot
>jumper cable that came with the VCR to connect it to the TV, get rid of it
>and replace with a good quality cable - those cables are junk.
Yes. This is quite good advice. A major problem with both MATV and CATV
systems is leakage caused by lousy connections.
73,
Jim K9YC
------------------------------
Message: 6
Date: Wed, 13 Feb 2008 10:28:39 -0600
From: dgsvetan@rockwellcollins.com
Subject: Re: [RFI] TV RFI - an update
To: rrath@charter.net
Cc: rfi@contesting.com
Message-ID:
<OFFDAE3AD4.494D88A5-ON862573EE.0058C6D2-862573EE.005A83CF@rockwellcollins.com>
Content-Type: text/plain; charset="US-ASCII"
Rod,
Jim Brown, K9YC, gave you some excellent input regarding the number of
beads needed to obtain useful results in his posting. I'll only add that
unless your problems are stemming from SSB operation on either 10m or 6m,
mix 43 is NOT what you want. Its primary effectiveness range is roughly
30 MHz to about 300 MHz. That's why it is so popular (lots of 2m and 6m
ops out there, plus that is also the frequency range in which most
computers have a lot of emissions). If your on-order toroids are #43, it
might be worthwhile to contact the vendor and try to get a mix better
suited to your needs.
For those of us who may have missed earlier information on your situation,
please supply the following info:
- Band or bands in which you are operating and which cause the worst TVI
- Your transmit power level
- Orientation of your antenna(s) relative to the affected TV set and VCR
(distance away from and above, off the end or broadside, etc.)
- Type of antenna(s) you use (dipole, yagi, etc.)
I do have a neighbor to the south of me (at a distance of at least 300
feet) who sometimes complains that I cause him grief when I am on 6m SSB
or AM and aim my yagi directly toward his house. He is on satellite dish
TV and has 2 converter boxes; one is affected by my 6m operation and the
other is not. Why, I don't know, except that the non-affected box is at
the other end of the house, making it that much further from my antenna.
He doesn't consider it to be a major enough problem to warrant an
investigation, so I don't worry about it too much. It so happens that my
need to aim the beam directly south for 6m QSOs is actually quite seldom.
Most of the TV cables in my house were built by me. I use decent crimp-on
connectors applied to high quality (Belden or equivalent) RG-6/U cables
and crimped with the proper tool - no pliers. If a cable proves to be
bad, I have only myself to blame, plus it is easy enough to either repair
or replace it.
Good luck.
73, Dale
WA9ENA
rrath@charter.net
Sent by: rfi-bounces@contesting.com
02/12/2008 08:01 PM
To
rfi@contesting.com
cc
Subject
Re: [RFI] TV RFI - an update
Here is an update to my TVI:
Well my wife bought some snap on beads - 43 mix - and I put all 5 of them
on the power cord. Bought a High Pass filter, put it in-line; this all is
put on
the VCR. Reason for the VCR and not the TV, the VCR is receiving the TVI
and sending it to the TV. VCR on we get massive TVI. VCR off hardly any,
but some.
No change. Blaring SSB coming thru the TV speaker and lines wiping out
the picture.
I rapped the VCR with aluminium foil with all the other items still in
place.
No change. Blaring SSB coming thru the TV speaker and lines wiping out
the picture.
I then put the snap on beads on TV, after removing them from the VCR.
No change. Blaring SSB coming thru the TV speaker and lines wiping out
the picture.
I do have 6 torroids coming. I will rap the power cord for both the TV and
VCR and rap the 75 ohm antenna cable. That will leave three torroids left.
Might have to add two torroids to the TV, VCR and the cable line.
Will let you know how things turn out.
Rod
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http://lists.contesting.com/mailman/listinfo/rfi
------------------------------
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End of RFI Digest, Vol 62, Issue 6
**********************************
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