I do not have cable or satellite television so I rely on Over-The-Air digital programming (free) and Internet streaming services to provide entertainment.
A couple years ago, I purchased a video card for my desktop PC which provides simultaneous HDMI and DVI outputs -- the HDMI cable is connected to my television and the DVI connection is for my computer monitor. The outputs mirror each other so that whatever I see on the Desktop monitor is available on my 65" Panasonic TV whenever I have the TV's input set to the HDMI port that the computer's HDMI cable is connected to. This setup has worked amazingly well, but just his weekend I noticed an issue:
A few years back, one of the regional over-the-air broadcasting stations had their 2000 foot transmitter antenna tower collapse. Prior to the collapse, I never had any issues receiving their signal. Unfortunately, after the collapse, the broadcasting company decided to retain the same output transmission power, but built the replacement tower significantly shorter. Consequently, I thought I had lost those channels forever.
This weekend, I performed a re-scan of channels on my TV and to my surprise (and joy!) found that these lost channels were again available! The signal is not the strongest, but since the broadcast is digital, everything looks great.
So while I was watching the programming on these rediscovered channels, all of the sudden I heard my Desktop PC wake-up (the fans start buzzing, the speakers crackle for a brief moment.. very common since the computer is always running Skype in the background). Well as soon as the computer wakes up, I notice my television signal is no longer available. I thought that peculiar timing so I tried unplugging the HDMI cable from the TV...and voila the content returned immediately, crystal clear.
Any ideas why the HDMI signal is causing interference like this? I've done some googling and found similar complaints for Chromecast device used with over-the-air TV, but have not found the explanation as to why it happens?
The TV is connected to an external outdoor antenna on top of the house. The antenna can be rotated, but the direction of the antenna does not make a difference for this channel.
Other TV channels (stronger signal) are received just fine when the HDMI signal is connected to the TV
The Desktop computer and television are on different circuits, but wired to the same ground (no ground loops)