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Author Topic: I am causing my neighbor's TV and Blue Ray player to cycle on and off  (Read 27522 times)
KB1NXE
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Posts: 363




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« Reply #15 on: March 23, 2012, 01:50:53 PM »

Most remotes are infrared and placing them under a baking pan should have little effect. 

 If you put a pillow on the remotes and it still happens, it's not the remotes. 

Now think about this. If it was remote being effected, a metal shield would block TVI on it, not a pillow. Also, a remote is not even powered up until you press a button on it.

Realistically, running 100 watts 15 feet from a TV is really asking for trouble. RF field is going to be real strong and will overwhelm some devices. I really feel that low power and some filtering is only viable option here.

Now think about this.  If you put a pillow on it, the Infrared beams can't reach the TV!
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W8JX
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Posts: 6670




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« Reply #16 on: March 23, 2012, 02:48:55 PM »

Most remotes are infrared and placing them under a baking pan should have little effect. 

 If you put a pillow on the remotes and it still happens, it's not the remotes. 

Now think about this. If it was remote being effected, a metal shield would block TVI on it, not a pillow. Also, a remote is not even powered up until you press a button on it.

Realistically, running 100 watts 15 feet from a TV is really asking for trouble. RF field is going to be real strong and will overwhelm some devices. I really feel that low power and some filtering is only viable option here.

Now think about this.  If you put a pillow on it, the Infrared beams can't reach the TV!

Nor can they under a pie plate.
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KB1NXE
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« Reply #17 on: March 23, 2012, 09:02:46 PM »

Unless it's glass.  But a pillow is generally right there!
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K5LXP
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Posts: 4536


WWW

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« Reply #18 on: March 24, 2012, 06:22:08 AM »

I've decided to take it all down and play with my Morse Machine simulator instead.  No problems this way.

FWIW, I have my butternut vertical on the roof directly over my livingroom and it's been there for the past 10 years without issue.  It *is* possible.

So sad you gave up without even trying anything.  You'll never know how much fun operating you may have missed out on.


Mark K5LXP
Albuquerque, NM
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WX7G
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Posts: 6324




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« Reply #19 on: March 24, 2012, 07:32:36 AM »

Some of my most fun operating has been from apartments. It is a challenging environment and when you get everything working and TVI taken care of the contacts can mean even more.

I feel good thinking about all the DX I worked from one apartment by loading the balcony railing against a radial (I didn't know at the time that the radial was doing most of the radiating) and working a 160 meter contest from another apartment using a 100' center loaded dipole up 15'. It was made of #36 wire and no one noticed it.

One apartment antenna consisted of a 10 meter loop strung on lamp hooks that were already in the ceiling. I fed it with twin lead to a tuner and ran it as a closed loop on 10 meters and an open loop on 20 meters.

Sometimes it's best to keep it quiet. No SSB (they can hear you talking), run CW with headphones on, and hide the antenna inside your apartment. The MFJ-933 loop tuner is good for this. Then if you cause TVI nobody knows where it's coming from. No ham antennas on the car either.

« Last Edit: March 24, 2012, 07:34:17 AM by WX7G » Logged
W8JX
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Posts: 6670




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« Reply #20 on: March 24, 2012, 09:15:44 AM »

Sometimes it's best to keep it quiet. No SSB (they can hear you talking), run CW with headphones on, and hide the antenna inside your apartment.

Not sure CW is always answer. It is possible that a Digi mode would work best to low power with a constant signal level vs CW's pulsing or SSB modulation varying RF field constantly which may cause more RFI than a constant low level signal. 
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KC9TNH
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« Reply #21 on: March 26, 2012, 04:07:09 AM »

Hex Beam up 30'... I am using LMR-400 cable, about 20' to a lowpass filter, a tuner, and then to the radio.
Question for the group:
Would it be of benefit to run the lowpass filter in the shack between radio output and the tuner, keeping those connections as short as possible?
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73
Wes -KC9TNH
"Don't get treed by a chihuahua." - Pete
WX7G
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Posts: 6324




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« Reply #22 on: March 26, 2012, 11:13:16 AM »

The problem appears to be fundamental (frequency) overload and not harmonic content. A LP filter will not help.
« Last Edit: March 27, 2012, 01:43:07 PM by WX7G » Logged
W8JX
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Posts: 6670




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« Reply #23 on: March 26, 2012, 11:30:42 AM »

The problem appears to be fundamental (frequency) overload and not harmonic content. A LP filter will no help.

Yes a low pass filter will do nothing with RFI from being in a strong RF field.
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KC9TNH
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« Reply #24 on: March 26, 2012, 12:21:12 PM »

WX7G & W8JX, thanks!
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73
Wes -KC9TNH
"Don't get treed by a chihuahua." - Pete
K8AC
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Posts: 1478




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« Reply #25 on: March 27, 2012, 12:25:49 PM »

Quote
It does seem odd that both the TV and the Blue Ray player shut off. Might it be just one of them?

Are the TV and Blu-Ray player SONY?  Turning on the SONY player will also turn on the TV if it's a SONY, and I think turning the player off then turns off the TV as well.  The HDMI cable probably serves as the com link in that case.  I'd put my money on the player being the source of the problem.  I have the SONY setup here, but have never had a problem with 1500W from a nearby yagi.
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W8JX
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Posts: 6670




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« Reply #26 on: March 28, 2012, 02:46:09 PM »

I have the SONY setup here, but have never had a problem with 1500W from a nearby yagi.

Bet it is not 15 feet over living room.
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N2UGB
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Posts: 179




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« Reply #27 on: March 29, 2012, 08:03:40 AM »

My gosh, my friend, go QRP. With that antenna you should do ok at five-watts. I do and I only have a Buddistick out the window.
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KL7CW
Member

Posts: 81




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« Reply #28 on: April 02, 2012, 12:15:59 PM »

I would completely unhook the blue ray player and determine if you interfere with the tv.  If the blue ray is the problem, possibly you could trade him for a unit not so RFI sensitive....perhaps a 3 way trade through another relative or friend far away from ham transmitters.  Also if you have some known good spare cables you could try them on his set up.....occasionally poor cables and/or connections can be the cause. 
In my 57 years as a ham, I have found that 5 watts will seldom cause trouble, but 100 watts sometimes does, especially with the transmitting antenna close by (say 50 ft or so) reduce your power by 3 db (or more?) may be a solution.  Perhaps you can run 25 or 50 watts on some bands or with some beam headings (probably the beam is not too directional directly downward). Also make sure you use a balun or incorporate some type of coax choke at the antenna, and route the coax down, but also away from the area directly above the blue ray.  I think it is rather unlikley that radiation from the coax could be the problem, but good practice would be to make sure the SWR is reasonable (say less than 2:1) and use a coax choke or balun at the antenna to decouple currents from the coax shield.  Even if this does not solve the Blue Ray problem, it may improve RX noise and/or the antenna beam pattern. 
My gut feeling is that 100 watts at 15 ft is probably just pushing both the human exposure level and the intensity of RF fields into consumer electronics to a higher level than I would like...even if your evaluation shows it is legal.  I have knowingly exposed myself to higher RF levels, however I would never expose my family or neighbors to excessively high levels of RF.  If you need to run say 25 watts instead of 100 watts, you will seldom notice the difference, especially if you operate CW.  The exception may be in trying to break a DX pile up or in a contest.  I am mostly a QRP operator (my choice..its fun for me !) however if you need to reduce your power level all the way down to 5 watts (on CW) it is a different experience.  It is possible to work the world with QRP, but it takes operator skill and much patience.     Rick   KL7CW   Palmer, Alaska
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KL7CW
Member

Posts: 81




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« Reply #29 on: April 02, 2012, 02:14:37 PM »

I think finding out the level you can operate with without causing RFI would be very helpful.  For example if 25 watts is OK, this is a 6 db decrease from 100 watts.  Reducing power to 50 watts would reduce RFI by 3 db.  IF the RFI comes in through cables or power cords, it is often very easy to get 5 or 10 db of attenuation with ferrites.  Raising your antenna as little as 5 or 10 feet could easily reduce RFI by more than 3 db.  Please remember your antenna pattern 15 feet away (near field) is not at all like the distant (far field) pattern which probably shows very little radiation straight down.  As you raise your antenna the pattern starts to look more like the far field pattern with little straight down or straight up radiation.  If your signal enters the blue ray through various mechanisms or you need say a 20 db reduction in RF, then all bets are off.  I have found that HF RFI on a cable shield (common mode) can often be reduced around 10db or sometimes more with a single ferrite core made of the correct material for the frequency you are trying to supress.  Once again I agree with the observation that 100 watts only 15 feet above living quarters is probably pushing what is a prudent level.  50 watts 20 or 25 feet away sounds much better to me.  PS:  I would just about bet that raising you antenna 5 or 10 feet higher would gain you at least 3 to 6 db....so if you could raise your antenna and reduce power you would probably not lose anything, and would probably have a less noisy receive antenna in the bargain.  I have noticed that moving a receive antenna as little as an additional 5 feet away from a building can cut receive noise by MANY db.    Good Luck  Rick  KL7CW 
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