matt > 140

…more than I can tweet…

Today I Replaced My TV Antenna: Why VHF Still Matters

tumblr_inline_om3a16jHfo1rvl0vd_1280

About a week ago, my wife asked, “Hey, what happened to Channel 2?”

WJBK, FOX 2 out of Detroit, and all its sub-channels (2-2, 2-3, and 2-4), had stopped showing on all our TVs. The message on each TV was something like “no signal”. Every other channel worked fine.

It’s been a year since I cut the cord and went with a combination of OTA broadcast HDTV,  Tivo, AppleTV, Netflix, and Amazon Prime Video. But that’s a different story. This is the story about how last week I realized I had the wrong antenna.

I always try to think about what changed, when something like this happens. Things don’t “just break”. I had recently rerouted my outdoor speaker wires under my deck, and in the process, I also tidied-up my RG6 antenna cable that runs under the deck too (it’s an elevated deck above a walk-out basement). I used metal wire clips (clamps?) to fasten the RG6 to the underside of a steel C-channel joist and then zip-tied the speaker wires to the RG6. Could this have introduced interference?

I had been careful to cross any electrical wires at right angles wherever possible (as you are supposed to, to prevent interference), so I spent hours researching whether the steel clips could be the issue. I’ve seen installers use plastic and steel clamps without issue, but I did read a post in a forum that suggested that certain metal clamps could cause an issue if they pinched the RG6. My clamps didn’t, but I figured I’d go ahead and replace them with plastic ones when I get a chance.

But I wasn’t satisfied with that answer; it really bothered me that only one channel was impacted. So I tried an experiment to measure the signals of stations with transmitters located about as distant as WJBK. I have a little 1byOne HDTV tuner that I bought for testing different antennas and antenna locations before I cut the cord. It’s small and easily portable and has a handy signal meter feature, and it’s perfect for doing signal tests without requiring a professional coax signal meter. I plugged the little tuner into the main antenna cable, before the splitter to get the best measurement, and checked out the signal levels of all the channels I normally receive, including WJBK.

According to AntennaWeb, WJBK is one the furthest transmitters from my house, about 23 miles. WDIV is a mile closer, and nearly in the same direction as WJBK, and its signal comes in strong and clear.  WWJ is a mile further, in a slightly more southern angle from my house, and likewise its signal comes in strong and clear.  WJBK signal was at about 10-14%. Turning on the antenna’s power amplifier just made added intensity to the bad signal (kind of like turning how up the volume doesn’t help a radio station come in any better).

So now the mystery shifted from “what did I do to the cable” to “what is different about WJBK?”

HDTV stations all broadcast on UHF. UHF, for Millenials and younger, was the secondary dial on the old TVs, where you would tune to any channel higher than 13. The VHF dial had channels 2 through 13.  So, even though the primary Detroit channels are known as 2, 4, 7, 20, 50, 56, and 62, they no longer broadcast on those channels. They broadcast on channels in the UHF range. For example, WDIV Channel 4, though it used to be broadcast on VHF channel 4, is now actually broadcast on UHF channel 45. The modern TV tuners hide this from you so the TV channels can keep their historical channel numbers more as brands than anything else.  So you have to keep in mind there are 2 numbers associated with any TV channel: the displayed/named channel, and the FCC-defined channel.

But hang on, WJBK Channel 2 broadcasts on channel 7? Channel 7 isn’t in the UHF band. What is this now?

It turns out, some HD broadcasts are in the “HI-V” band, not UHF.  HI-V is the upper range of the VHF band, channels 6 through 13, and UHF antennas will do a poor job receiving it.

I had thought my antenna was both VHF and UHF. The page on Amazon where I bought it even said so: the ANTOP 400B. Researching the ANTOP web site showed me this was incorrect, however. The model that has VHF capability is the ANTOP 400BV.

Well, it’s been almost a year since I bought that antenna, and Amazon wouldn’t let me return it or give me a refund, so I decided to just buy the right one and sell the old one on eBay.

So, today I installed the new antenna, WJBK comes in great and, as a huge bonus, so does CBET — Channel 9 out of Windsor, Ontario, Canada!

I never did figure out why WJBK worked and then suddenly didn’t. It determined it wasn’t what I was did with the cable clamps, since a few days later WJBK started coming in fine again without me doing anything at all. It could have been the weather, sunspots, who knows. WJBK’s signal was still about half of what the UHF channels were, so replacing the antenna was still worth it because now I have a more robust signal for HI-V  channels, no more dropouts or occasional pixelation on WJBK, and the bonus of CBET.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Information

This entry was posted on August 25, 2018 by .

Navigation

Connect

Advertisements

Twitter Feed

Error: Twitter did not respond. Please wait a few minutes and refresh this page.

Disclaimer

Anything Matt Hovey publishes online is his own personal opinion and does not reflect the opinion of his employers.
%d bloggers like this: