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We have an antenna mounted around 15 feet in the air with around a 20 ft run of RG-6 cable to a grounding block. The ground block is not grounded though just used as a coupler. After the grounding block a run of around 30 feet of brand new RG-6 is used and goes into an ancient two way splitter behind the tv. The two leads are then two short equal lengths of RG-6 cable one going to the TV and the other to the HTPC for recording. The system works great for many channels but suffers with some. When the HTPC is on no matter playing a stream of just idling certain channels on the TV go out. Once the HTPC goes off the interference stops and it works perfectly fine. I have tried directly connecting the wire to the tv bypassing the splitter and DVR and the same results occur. The HTPC and TV are both plugged into an expensive surge protector. Does anyone have any idea what this could be or how to fix it? I am assuming its some type of interference from the HTPC but I cant figure out what it could be. On a second note similar occurs when the microwave on the opposite wall a room away is used. When powered on the TV signal goes completely out. The microwave is on a complete separate electrical circuit and the only connection I can find is that the cable from the antenna runs on the wall outside behind the microwave but there is Sheetrock, insulation, plywood, and siding between them. I am not sure if they are somehow connected. Does anyone have any idea what the interference can be? I am more concerned about the HTPC and TV operating at the same time then the microwave. I have read some things about grounding and how it may help to ground the antenna to the main houses electrical ground but that over 20 feet from the exterior grounding block.
 

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Sounds like the antenna is too close to these other devices and they're causing interference. We need the link to your TV Fool report to get an idea what sort of signal levels you're dealing with. Could be they're pretty weak to begin with and it doesn't take much interference to wipe them out. Computers can be notorious for generating RFI.

What's the actual distance from the antenna to the HTPC and the microwave?
 

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Discussion Starter · #3 ·
Sounds like the antenna is too close to these other devices and they're causing interference. We need the link to your TV Fool report to get an idea what sort of signal levels you're dealing with. Could be they're pretty weak to begin with and it doesn't take much interference to wipe them out. Computers can be notorious for generating RFI.

What's the actual distance from the antenna to the HTPC and the microwave?
The antenna would be closest to the microwave with a difference of maybe 7 feet vertical 3 Horizontal (on a roof peak). Distance from microwave to HTPC is just under 25ft with a wall in the path. And I will get back with a TV Fool report but i do know that it interferes with one channel which is located 28 miles away and appears to have a strong signal
 

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The antenna would be closest to the microwave with a difference of maybe 7 feet vertical 3 Horizontal (on a roof peak). Distance from microwave to HTPC is just under 25ft with a wall in the path. And I will get back with a TV Fool report but i do know that it interferes with one channel which is located 28 miles away and appears to have a strong signal
Sounds like this could be a VHF-Lo problem. TV RF channels 2 thru 6 can get wiped out by interference caused by running appliances or any other RFI. That is why the location of your antenna is extra important when trying to receive these stations as opposed to those on VHF-Hi & UHF.

Also, you should know that the TV Fool database is almost three years out of date. Some TV stations are missing, too. Keep that in mind when using the website.
 

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We have an antenna mounted around 15 feet in the air with around a 20 ft run of RG-6 cable to a grounding block. The ground block is not grounded though just used as a coupler. After the grounding block a run of around 30 feet of brand new RG-6 is used and goes into an ancient two way splitter behind the tv. The two leads are then two short equal lengths of RG-6 cable one going to the TV and the other to the HTPC for recording. The system works great for many channels but suffers with some. When the HTPC is on no matter playing a stream of just idling certain channels on the TV go out. Once the HTPC goes off the interference stops and it works perfectly fine. I have tried directly connecting the wire to the tv bypassing the splitter and DVR and the same results occur. The HTPC and TV are both plugged into an expensive surge protector. Does anyone have any idea what this could be or how to fix it? I am assuming its some type of interference from the HTPC but I cant figure out what it could be.....
Is there any change in the effect of the HTPC if you disconnect the antenna lead to it (removing one common ground via the shield) ?
 

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1. We have an antenna mounted around 15 feet in the air with around a 20 ft run of RG-6 cable to a grounding block.

2. The ground block is not grounded though just used as a coupler. I have read some things about grounding and how it may help to ground the antenna to the main houses electrical ground but that over 20 feet from the exterior grounding block

3. After the grounding block a run of around 30 feet of brand new RG-6 is used

4. and goes into an ancient two way splitter behind the tv.
1. Sounds fine. Be sure it's ATSC-compatible and handles both UHF and VHF. However, at my brother's house, we hooked-up the old antenna from the 90's and it works fine for digital.

2. It should be grounded. Just run a heavy gauge wire to it, and then to earth ground. It will (likely) protect your nice machines in case of lightning-strike. It also helps with interference (by connecting the coax-shield to ground).

3. All wiring should be "good/serviceable" RG-6 and all connectors in good shape (no corrosion). You have to open them and look. It should not be run close to any AC 120v power lines, fluorescent lights, etc.

4. If old or questionable, replace it. And remember, every time you install a splitter, you take a signal-db hit (it usually says how much on the splitter). I would run a single piece of coax from antenna directly to a "powered" splitter (installed at "whole house"distribution point).

That way, there should be virtually no signal drop.
 

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1. Sounds fine. Be sure it's ATSC-compatible and handles both UHF and VHF. However, at my brother's house, we hooked-up the old antenna from the 90's and it works fine for digital.
No such thing as an ATSC/HD antenna. RF is RF and any antenna designed for TV RF frequencies will work.
 

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We do need your location and a TVFool link. It's hard to diagnose this without knowing which stations are showing the issue as different types of interference affect different frequencies. That's why we put those questions in the READ BEFORE POSTING section above. If you don't have enough posts to post a link or the system otherwise doesn't allow you to, the workaround is in the READ BEFORE POSTING article.
 

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Discussion Starter · #9 ·
1. Sounds fine. Be sure it's ATSC-compatible and handles both UHF and VHF. However, at my brother's house, we hooked-up the old antenna from the 90's and it works fine for digital.

2. It should be grounded. Just run a heavy gauge wire to it, and then to earth ground. It will (likely) protect your nice machines in case of lightning-strike. It also helps with interference (by connecting the coax-shield to ground).

3. All wiring should be "good/serviceable" RG-6 and all connectors in good shape (no corrosion). You have to open them and look. It should not be run close to any AC 120v power lines, fluorescent lights, etc.

4. If old or questionable, replace it. And remember, every time you install a splitter, you take a signal-db hit (it usually says how much on the splitter). I would run a single piece of coax from antenna directly to a "powered" splitter (installed at "whole house"distribution point).

That way, there should be virtually no signal drop.
Brand new Antenna. Does tend to be more optimized for UHF reception though. I know it should be grounded, but need to find some cable. All connectors are brand new no corrosion on the cable and the majority of the cable run is brand new. Only around 20ft are older cable but has new ends and is RG-6. Antenna is around 10 feet horizontally from the main power line though. And I do have suspicion in the splitter and will purchase a distribution amp when officially cutting the cord.
 

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Discussion Starter · #10 ·
We have an antenna mounted around 15 feet in the air with around a 20 ft run of RG-6 cable to a grounding block. The ground block is not grounded though just used as a coupler. After the grounding block a run of around 30 feet of brand new RG-6 is used and goes into an ancient two way splitter behind the tv. The two leads are then two short equal lengths of RG-6 cable one going to the TV and the other to the HTPC for recording. The system works great for many channels but suffers with some. When the HTPC is on no matter playing a stream of just idling certain channels on the TV go out. Once the HTPC goes off the interference stops and it works perfectly fine. I have tried directly connecting the wire to the tv bypassing the splitter and DVR and the same results occur. The HTPC and TV are both plugged into an expensive surge protector. Does anyone have any idea what this could be or how to fix it? I am assuming its some type of interference from the HTPC but I cant figure out what it could be. On a second note similar occurs when the microwave on the opposite wall a room away is used. When powered on the TV signal goes completely out. The microwave is on a complete separate electrical circuit and the only connection I can find is that the cable from the antenna runs on the wall outside behind the microwave but there is Sheetrock, insulation, plywood, and siding between them. I am not sure if they are somehow connected. Does anyone have any idea what the interference can be? I am more concerned about the HTPC and TV operating at the same time then the microwave. I have read some things about grounding and how it may help to ground the antenna to the main houses electrical ground but that over 20 feet from the exterior grounding block.
Here is the TV Fool link
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=903824830b3ce7
 

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Also make and model of the antenna.
 

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1. Brand new Antenna.
2. Does tend to be more optimized for UHF reception though.

3. Antenna is around 10 feet horizontally from the main power line though.
1. Good. I wonder what model?

2. As are many new ones. I prefer a more well-rounded antenna (tuned for both VHF and UHF) .

3. Unusual. Not sure what happens then. Maybe you temporarily have to use/test an antenna at a more normal distance away from power lines? Especially if they are 480v or higher (like try the back yard).

https://www.cordcuttersnews.com/top...pacting-over-the-air-tv-reception-guest-post/
 

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Some things that may or may not help the problem:

1st - Ground that outdoor antenna, a proper ground would be tied to both earth ground, and the home's electrical system ground, but 1 or the other is still better than none.

2 - You can always try an LTE Filter at the TV's antenna input ( https://www.amazon.com/dp/B00L5B0W8S?ref=myi_title_dp ) , Microwaves cook ("transmit") above 2ghz , and the DVR could possibly be radiating some harmonics/RFI above 800Mhz, and these filters greatly attenuate signals above TV channels, that could overload or interfere with certain specific channels in the receiver ....

3 - There are "good" ($$) Plug-in EMI/RFI AC line filters that work "both ways" , If one is put on the TV's power cord, they block EMI/RFI from riding up the house wiring into the set, & if put on the microwave and DVR, they prevent the appliance's interference from riding down it's AC line and entering the house wiring.
 

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1. When the HTPC is on no matter playing a stream of just idling certain channels on the TV go out. Once the HTPC goes off the interference stops and it works perfectly fine.

I have tried directly connecting the wire to the tv bypassing the splitter and DVR and the same results occur.

2. The HTPC and TV are both plugged into an expensive surge protector.
1. As I re-read OP ... this is telling.

2. This should be a good UPS (like APC with AVR-tech).
 
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Discussion Starter · #17 ·
1. Good. I wonder what model?

2. As are many new ones. I prefer a more well-rounded antenna (tuned for both VHF and UHF) .

3. Unusual. Not sure what happens then. Maybe you temporarily have to use/test an antenna at a more normal distance away from power lines? Especially if they are 480v or higher (like try the back yard).

https://www.cordcuttersnews.com/top...pacting-over-the-air-tv-reception-guest-post/
Model is a: GE Pro Outdoor/Attic Mount Antenna, 70 Mile Range, VHF/UHF Channels, 29884
I agree a more rounded antenna would have been a better investment.
Power lines are 240v. I have tried an old set of rabbit ears with UHF loop around the house and they do appear to work. Never checked if have interferance with that TV and HTPC though.
 

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We still need to know which Stations are affected by Interference generated by HTPC. If you are TRYING to receive Ch2 or Ch6, be advised that GE-29884 is primarily a UHF Antenna, with a simple 0 dBd Gain Dipole for Ch9 and NEGATIVE Gain with excessive SWR for Ch2/6. I can provide advice re simple DIY Indoor (or Attic) Antennas for Ch2 and/or Ch6 if you let me know which you are interested in TRYING to receive.

Most Surge Protectors have minimal IF ANY suppression of RFI/EMI....and only a FEW are capable of providing RF Isolation between the various attached Devices in order to suppress EMI/RFI generated by HTPC from being conducted to OTHER devices via the AC Power Cord. I would recommend that you purchase one of the Tripplite ISOBAR Surge Suppressor Power Strips [and ISOBLOC Wall Outlets], which provide ample RF Isolation BETWEEN the attached Devices, such as the following:
https://assets.tripplite.com/brochure/tripp-lite-premium-surge-suppressors-brochure-953229-en.pdf
https://www.amazon.com/Tripp-Lite-Protector-Right-Angle-ISOBAR6ULTRA/dp/B0000510Z9 [2 Outlets]
https://www.amazon.com/IBAR4-6D-Isobar-Spaced-Protector-INSURANCE/dp/B00005119M [4 Outlets]
https://www.amazon.com/Tripp-Lite-Protector-Right-Angle-ISOBAR6ULTRA/dp/B0000513US [6 Outlets]
https://www.amazon.com/Tripp-Lite-Protector-Right-Angle-ISOBAR6ULTRA/dp/B0000511U7 [8 Outlets]

If you are looking for a less expensive alternative, many BELKIN Surge Protectors also offer RFI/EMI Filtering, although not as much as ISOBARs provide, for example:
https://www.amazon.com/dp/B002QPZXH2

I DO NOT advise running TV/Cable Coax thru the Coax Filter/Surge Protective Device included in SOME Power Surge Strips....the LAST thing you want to do is to have VERY high voltage (and EMI/RFI signals) come anywhere NEAR your sensitive and pricey Electronics. IF you think you WANT this sort of protection, there are devices that screw into the Ground Block...which MUST be Grounded to drain off Static Electricity that forms when high winds blow across the Ungrounded Elements in a TV Antenna:
https://www.digitalhome.ca/forum/18...gh-attic-antenna-side-side-2.html#post1463911
Sorry about the missing links in this 2012 post...here are a couple that I could recover:
https://www.digitalhome.ca/forum/18...gh-attic-antenna-side-side-2.html#post1463911
http://lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf

In ADDITION to suppressing Interference Conducted via the HTPC's Power Cord, you will likely ALSO need to suppress Interference Conducted (and Emanated) via OTHER HTPC Cable Connections....including one around Power Cable JUST AFTER it exits the HTPC to suppress Emanated Emissions (i.e. via the Air FROM HTPC's Power Cable). A bag full of the fol. Clamp-On Ferrite EMI Suppressors can be used on ALL of these other Cables:
https://www.amazon.com/s?k=ferrite+suppressor [Note Bag of Assorted Sizes is available]

FYI: An LTE Filter MAY or may NOT help your situation, so you might want to consider it after all other alternatives have been thoroughly explored. Also be advised that I have not YET seen any LTE Filters designed for the NEW UHF Band (470-608 MHz) which is currently being implemented [San Diego RESCAN DAY was 14 Mar, rest of SOCAL is mid April]....so you will NOT be protected from possible LTE 600 MHz Band Interference [existing or soon to be activated] using currently available LTE Filters, such as from C-M, et. al.
 

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1. Model is a: GE Pro Outdoor/Attic Mount Antenna, 70 Mile Range, VHF/UHF Channels, 29884
I agree a more rounded antenna would have been a better investment.

2. Power lines are 240v.
1. Looks fine.

2. Maybe, but likely higher (unless it is the one just for your house).
 

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I DO NOT advise running TV/Cable Coax thru the Coax Filter/Surge Protective Device included in SOME Power Surge Strips....the LAST thing you want to do is to have VERY high voltage (and EMI/RFI signals) come anywhere NEAR your sensitive and pricey Electronics.
I used to think the same thing, until I realized the coax is running from outside ... directly into my nice:
Cable-TV-ISP: Cable Modem, router, and network switches (for starters)
OTA/ATSC: LG 4K HDTV

And yes, both coax-lines are properly grounded outside.

So, that is corrected now (using coax-filter on nice APC) and everything still works fine. Plus, his is also a HTPC install, so the PC and whatever else needs to be on a good UPS anyway.

Isn't EMI/RFI interference mainly an analog thing? This is a digital signal.

And remember that as sketchy and un-finished as his install is ... he said his antenna and coax cables WORK FINE as long as HTPC is turned OFF.
 
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