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Old 23-Dec-2016, 4:50 PM   #1
JusMe
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Question Weird Signal Dropping

I've been using a basic antenna for quite a while now, as I only really want the late night news broadcast. Been working okay.

But Wednesday (two days ago) a new tenant moved into the apartment next to mine. I've learned that she doesn't yet have a tv, so I suspect some other electronic device might be the "culprit."

I get a great clear signal and picture from different broadcast towers all day and into the evening, when I turn the tv on about 7:30 pm. Then I use a non-broadcast input.

When I turn back to see the news about 11:00 pm, there's no signal whatsoever. But later, sometime shortly after midnight (i.e. going to bed time?) I can get a clear signal and picture again.

I suspect, and only suspect as I haven't had a chance to speak to the new tenant yet, that she's using some kind of electronic device during the evening that blocks the broadcast signal from my antenna.

This is really weird, and I will get a chance to speak to her, but she could be as clueless about the whole situation as I am.

Any ideas as to what might be blocking the signal completely (totally dropped, not just weak, and from more than one broadcast tower) for the few evening hours?
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Old 23-Dec-2016, 5:24 PM   #2
WIRELESS ENGINEER
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Virtually anything electrical can cause interference but what RF channel specifically is being impacted?

What kind of antenna are you using?

Have you tried moving the antenna to get a stronger signal?

Do you have the antenna by a window?

Last edited by WIRELESS ENGINEER; 23-Dec-2016 at 5:47 PM.
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Old 23-Dec-2016, 11:33 PM   #3
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Your previous thread for reference:
Illogical & Inconsistent Reception
http://forum.tvfool.com/showthread.php?t=15546
report
http://www.tvfool.com/?option=com_wr...f1f0248cd9778c
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Old 24-Dec-2016, 12:11 AM   #4
JusMe
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I'm using a small Terk antenna.

I had very good reception mid afternoon for a full five channels. Suddenly, at 5:50 pm (and I don't think anyone's home next door, so my speculation about the new tenant is now unlikely) ALL reception was suddenly dropped - nothing came in at all. I hadn't moved the antenna between those times.

I don't know about RF channels, but I was receiving CTV (CFRN) and CBC (CBXT) and ITV and YES and something else I can't remember. These are from a variety of towers in different locations and directions from me.

Now there's absolutely nothing, and moving the antenna around resolves nothing. Still not even a glimmer of reception.

http://www.tvfool.com/?option=com_wr...dfaf97862c6e3b

Last edited by JusMe; 24-Dec-2016 at 12:27 AM. Reason: Added Report Info
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Old 24-Dec-2016, 2:37 PM   #5
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Thank you for the new tvfool report.
Quote:
Then I use a non-broadcast input.
What is a non-broadcast input?

CKES is YES
CITV is ITV

Quote:
Now there's absolutely nothing, and moving the antenna around resolves nothing. Still not even a glimmer of reception.
The interference seems to affect UHF and VHF channels at a certain time of day. I agree with WIRELESS ENGINEER that it is probably very strong interference, maybe neon signs. If it were street lights, it would be all night. If it was coming from a nearby apartment, it might be CFL or LED lamps. Plasma TVs and battery chargers radiate interference.

Can you extend the antenna coax and try different locations for the antenna in your apartment to see which side it is coming from?
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Last edited by rabbit73; 24-Dec-2016 at 2:44 PM.
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Old 24-Dec-2016, 5:28 PM   #6
JusMe
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Quote:
Originally Posted by rabbit73 View Post
What is a non-broadcast input?
HDMI cable from my WD Media Player showing video files. I download all my viewing of movies and tv series, and only watch the late night news on broadcast.

Quote:
Originally Posted by rabbit73 View Post
Can you extend the antenna coax and try different locations for the antenna in your apartment to see which side it is coming from?
I've carried it around the living room to most possible locations, near and far from a window, high and low, back and forth across the room. When the signals are dropped, I get absolutely nothing. Curious that it's not just a single transmission tower, but everything.

I can possibly speculate that it might be interference from a massive seasonal moving LED display on a bridge about half a mile in direct sightline from my apartment balcony. Long distance, but very bright and active, and I'm groping for some explanation.

Last edited by JusMe; 24-Dec-2016 at 5:30 PM. Reason: Formating
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Old 25-Dec-2016, 12:04 AM   #7
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Does the timing of the bridge display match the signal loss?
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Old 25-Dec-2016, 5:32 AM   #8
JusMe
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Quote:
Originally Posted by rabbit73 View Post
Does the timing of the bridge display match the signal loss?
Not sure. I was out this evening when I think it began, and it's on now but I have no signal from any tower. Just 11:30 pm, but I think the display goes until about midnight, so I'm off to bed and will check it tomorrow.

On another completely unrelated note, just wondering why I'm not receiving email notices about responses to this thread. I have checked the "Instant email notification" box in the Thread Subscription Additional Options, but only discover anything by connecting and looking at the forum directly. No emails? Not serious but just wondering.


Next Day: checked today and as it's daytime with no light display, and no reception from any of the towers whatsoever. Perhaps someone in the building has a new plasma tv or battery charger or something, as it happened so suddenly. If it doesn't correct itself reasonably soon, I'll have to see about getting basic tv cable so I can have my late night news.

Last edited by JusMe; 25-Dec-2016 at 6:14 PM. Reason: Next Day Information
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Old 25-Dec-2016, 6:40 PM   #9
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One of the tools that I use to hunt for interference is a battery operated portable radio that tunes the AM broadcast band. If the interference is strong enough to affect TV reception, it will often be heard on AM. An FM portable doesn't work as well. Tune to a clear frequency at the low 540 end and listen; then try the 1600 high end. The built-in antenna acts like a direction finder. An AM radio in the car or a portable radio that tunes the Aircraft Band, which is also AM, can also be used.

If you did this:
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and you checked your other email folders besides Inbox like:
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Last edited by rabbit73; 25-Dec-2016 at 7:10 PM.
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Old 25-Dec-2016, 6:42 PM   #10
WIRELESS ENGINEER
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Don't know what term antenna you have or if it is possibly the trouble but you can try another antenna

A length of wire or a set of UNamplified rabbit ears etc

Any interference broad enough to wipe out vhf and UHF at the same time is rare so I suspect one very strong signal very close to your location is driving your tuner into AGC overload

You can use am radio to listen for electrical noise like what is created by motors, arcing insulators, etc
Just tune it to an under portion of the band and listen for buzzing noise that is so strong that it covers up local broadcast stations

If you can get your hands on a police scanner, you can make it search between say 140 MHz to 174 MHz looking for any signals that sound perfect with no antenna on the scanner

Also scan from 400mhz to 470 MHz doing the same

If you know anybody around the area that might have an old analog tv field strength meter, they could easily and quickly prove interference

Local TV antenna installers may have on or a local ham radio operator will usually have such equipment
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Old 25-Dec-2016, 7:20 PM   #11
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Quote:
Next Day: checked today and as it's daytime with no light display, and no reception from any of the towers whatsoever.
They must be home and not at work.

What channel do you use for the news?

If the interference is coming through the power line (conducted interference), then another circuit for the TV might help. A power strip with an RF filter might help.

If the interference is coming through the air (radiated interference), then grounding the coax shield with a grounding block might help.

Are your AC outlets 2-wire or 3-wire with a grounding pin?
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Last edited by rabbit73; 25-Dec-2016 at 7:29 PM.
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Old 25-Dec-2016, 9:37 PM   #12
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First, I'be solved the email notification problem. For some reason, Gmail was sending it into the spam folder. Just created a new filter that ensures nothing from TVFool goes there.

I don't have a portable radio, but can shift my stereo from FM to AM easily, and when the tv signal is dropped, I can try to see if there's interference on the radio signal.

Curiously, it seems that I sometimes can get a clear TV signal when I first turn the tv on, but that only lasts for a few minutes, and then it's gone.

I did try, a few days ago, a different antenna, with rabbit ears, and it didn't seem to make any difference. I'll give it another try just in case, and as I have the time.

All my AC appliances here in the apartment are two pronged and with one prong wider than the other, so can't shift them over. The outlets themselves are three pronged, but nothing I have other than the extension cable has a three prong plug.

The only channel I'me interested in seeing for the late night news is CFRN (CTV) 3.1 The only one I can get right now is YES-TV, 30.1 which holds no interest for me at all.

"grounding the coax shield with a grounding block might help." Not quite sure what you mean, but for my antenna, right new I'm using a length of speaker wire to extend from one side of the room around the floorboards to where the tv is, and then into a coaxial connector and into the tv itself with another short length of coaxial cable.

Edit: Tried the rabbit ears again - nothing. Tried using an extension cord for tv power across into the kitchen - nothing. Tried checking with the AM receiver on my bookshelf stereo - it's an incredibly old thing, the cd player quit so long ago I don't remember as I don't play CDs in it anymore, and could get nothing on the AM receiver, although the FM does receive the two or three radio stations I occasionally want.

Last edited by JusMe; 25-Dec-2016 at 10:04 PM. Reason: Tried something else
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Old 25-Dec-2016, 10:31 PM   #13
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Quote:
Curiously, it seems that I can get a clear TV signal when I first turn the tv on, but that only lasts for a few minutes, and then it's gone.
That's odd; I wonder if the TV itself is causing interference. Some streaming devices that attach to the TV, like the Amazon Fire TV, can cause interference.
Quote:
All my AC appliances here in the apartment are two pronged and with one prong wider than the other, so can't shift them over.
I understand that, most AC operated equipment has 2-wire polarized plugs. I was asking about the wall receptacle that you put the plugs into. A 3-wire wall receptacle can accept 3-wire plugs that ground equipment if it has it, and can provide a ground for equipment that doesn't if a good cold water pipe ground isn't available.



Quote:
The only channel I'me interested in seeing for the late night news is CFRN (CTV) 3.1 The only one I can get right now is YES-TV, 30.1 which holds no interest for me at all.
CFRN is on real channel 12, which is a VHF-High channel. CKES is on real channel 30, which is a UHF channel. VHF-High channels have more noise interference than UHF channels.
Quote:
for my antenna, right new I'm using a length of speaker wire to extend from one side of the room around the floorboards to where the tv is, and then into a coaxial connector and into the tv itself with another short length of coaxial cable.
Speaker wire?
Unshielded speaker wire?

That makes a very good antenna to pick up noise interference.

You should use only coax from the antenna to the TV antenna input jack, to reject interference.

What TV are you using?



A grounding block is not REQUIRED for an indoor antenna, but sometimes it helps to reject interference.

If the antenna is outside, the coax shield should be grounded with a grounding block that is connected to the house electrical system ground with 10 gauge copper wire for electrical safety and to reject interference. For further compliance with the electrical code (NEC in the US), the mast should also be grounded in a similar manner to drain any buildup of static charge which will tend to discourage a strike, but the system will not survive a direct strike.

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Last edited by rabbit73; 25-Dec-2016 at 11:04 PM.
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Old 25-Dec-2016, 10:58 PM   #14
JusMe
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Unlikely to be my own tv or anything else as I haven't changed anything at all for quite a long time, and this total droppage only began Wednesday night.

The wall sockets are three pronged.

Yeah, unshielded speaker wire. I know, but it was what was available when I set it up, and it's been working fine until now.

The TV is a 42" Avera, again, working fine using the HDMI input and until now, receiving the channel I want.

I have just called Telus, and despite the season, we're going to set up a time for them to instal their special box equipment, although I don't really want all the bells and whistles. However, as I signed a new lease recently for my apartment, the internet and basic tv is included - I just hadn't bothered about the tv stuff because my antenna was working okay.
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Old 25-Dec-2016, 11:10 PM   #15
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OK

Good luck with Telus.
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Last edited by rabbit73; 25-Dec-2016 at 11:13 PM.
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