TV antennas

[sfh074]

The previous post about the 1956 GE TV, reminded me of the big todo about the switch over from analog to digital TV years back.

I remember the digital TV sales people back then would tell you that you needed to change your TV antenna out for the "new digital signal" and try to sell you a smaller, sleeker more modern looking "digital" antenna so you could pick up the new TV signal over the air.

Well just like I always have, I went home and did a bit of research. Come to find out, the digital signal shares the same FM frequency band that the old analog vhf and uhf does. Actually the FCC stipulated that no new band or no widening of the current tv FM band would be added, so the new digital tv format had to share or reuse the old. So what does that say about the old school antennas that everyone had back in the 60's. You remember those huge tinticled monsters that everyone had attached to the chimneys. Well, if you were really into watching tv and wanted the most channels, you had the device that rotated that monster.

The greatest thing that came out of the digital OTA changeover was the fact that all metropolitan areas had to consolidate the transmitting antennas and group them in the same axis. Meaning that you no longer needed that device to rotate the antenna and can still pick up every channel.

So lets talk about that huge antenna vs the little "digital" antennas they sell today. If you live in a populated metro area, the little one will get you a bunch of channels since you only have to point it in a single direction since all the local channels are now grouped together in one single location or axis. But what about that huge antenna back in the day? What advantage did it have ..... especially if the new signals today reuse the same frequency band? Well FM is a lower power band and FM antenna effectiveness is directly related to surface area. The bigger the surface area, the better the signal. In other words the bigger the surface area, translates into picking up weaker or further out signals more easily. And the old huge antennas, just like the new digital tv antennas, are very directional. BUT ... unlike the new antennas, the huge ones are of course directional AND pretty good at multidimensional (if the signal is not too far away). The new antennas 1. Have very little surface area, and 2. Are very single direction.

So this leads me to my point. Back when the sales person tried to sell me one of those little "digital" ota antennas, I passed. Glad I did. When my research told me they were reusing the same frequency band, I went to Radio Shack and bought their 72" old school model and simply put it inside the attic .... pointing it at 182 degrees from north .... as directed by the one of many antenna pointing websites. That got me at the time all the Atlanta local stations plus a bunch more. I think when I had the tv scan for channels there were 35 dtv and 48 analog channels (2005 time frame).

A few months ago I bought a new led TV to replace an older plasma TV and hooked up the coax that leads up to the 72" monster up in the attic. I had the TV scann for channels and 133 dtv channels and almost as many analog channels (radio stations and some TV channels) showed up in the new lineup! I was like "are you kidding me?" After weeding out all the Hispanic channels and all the other bs garbage I was left with about 50 good channels in 3 different markets. South Carolina, North GA, and some from South GA. I bet if I could rotate that sucker, I could get more!

So after getting so many channels I was be-bopping thru walmart and saw one of those little "digital" TV antennas advertising just how many channels you could get with it. So I bought one for a little experiment. With a fresh 75' coax and the little antenna, I set it up on the 2nd story balcony with compass in hand. I pointed it at 182 degrees for the local channels. Put the tv in scan mode and scanned for channels. 31 dtv channels appeared in the lineup. I went back and tweaked the antenna a bit up and down and rescanned. This time 32 channels, but just a few with what the tv showed as "good" quality. I hooked back up my old school monster and rescanned. All of the 32 channels I got with the new antenna showed as "excellent" quality except for one. Not to mention 101 additional channels that the little "digital" antenna never even began to see!

Needless to say I boxed the pos antenna back up and returned it. Maybe next I'll go on ebay and see what those old school antenna rotators go for, for my next experiment.

Bud - Atlanta

 

[wayupnorth]

I have a similar old roof top antenna that came from K-Mart in the 1970's for $7.47. I receive every one of my local channels and the sub channels perfectly. I do not get locals on my satellite as they want an extra 10 bucks a month and do not include any sub channels.

 

[rp2813]

When we had some roofing work done at our previous house, I had the early '70s Radio Shack antenna taken down.  I sawed off the front section of it that included the UHF portion and placed it in the attic.  Reception was greatly improved compared to the set of rabbit ears I was using with a bowtie UHF antenna attached to it.  Channels didn't go blank anymore when fog engulfed the transmitter tower 45 miles north in San Francisco, and I didn't have to get up and adjust all the time.  I got more stations, and like Bud, I deleted the Asian and religious ones to make surfing easier. 

 

In our current house, only my 1950 Admiral isn't connected to cable.  Using the rabbit ears/bowtie rig, I get only a few stations because the set is on the ground floor.  It's not worth it to me to buy an old school antenna and put it in the attic.  The Admiral is a novelty item and isn't used for serious TV viewing.

 

[kate1]

We bought a big ‘super’ antenna just a few years ago. We’ve always been antenna people, now I supplement that with some online streaming, but I’ve never paid for cable or satellite. Getting the super antenna got us more channels and a clearer signal.

 

[kb0nes]

Indeed the form of modulation has NOTHING to do with the antenna. RF is RF all that matters is the frequency... If the antenna is touting that it is a "Digital" antenna to me that is a red flag.

Now back in 2007 when the transition hit, all the stations had to move into UHF frequency channels. This created issues for many as lots of areas didn't have UHF stations prior to that so the users didn't have UHF antennas. About 5 or so years after the DTV transition the FCC allowed some of the old VHF high band users to tack back their original channel frequencies with the new digital signal.

So indeed if you had an old antenna that was VHF/UHF it will likely serve you just fine. The old antennas are much larger then the new VHF/UHF models as they had to cover down to 50Mhz (ch 2) which makes the longest elements on the antenna nearly 10 feet long overall. Since they aren't using any of the lower VHF channels now the modern antennas are much smaller.

The website www.tvfool.com is a GREAT resource where you can enter your address and it will generate a list of all your local stations. The list will tell what real and virtual channel they are on as well as predicted signal strength and heading. A great resource for those looking to optimize reception

 

[mattl]

Back at the turn of the century - wow I can't believe I'm saying that--- I had a UHF antenna imported from England.  It was/is one of the highest gain antennas out there.  I coupled it with a high quality preamp to get a decent HD signal.  At that time the only stations in HD were at least 70 miles away and relatively low power.  I'm at 750' AMSL and on a 50' tower.  I was and am able to pull in stations from 3 markets.  I leave my antenna pointed at Detroit as the Flint stations I can pick up with a paper clip have never figured out how to manage an decent audio feed, the word inept comes to mind.

 

 

 

[gizmo]

a little bit of science helps understand antennas

Antenna element width determines which channels an antenna receives.
I'm not sure if the USA uses the same terminology, but here in Australia TV signals are divided into "bands", only bands 3 4 and 5 are used now. All analogue TV broadcasts are discontinued here, we only have digital, on Band 3 (VHF 6 to 12) band 4 (UHF 28 to 35) and band 5 (UHF 36 to 69). The old bands 1 and 2 are discontinued.

The old bands 1 and 2 had the really wide elements. Australia used to have a channel 0, below channel 1, and its elements were huge. Abandoning these stations means that antennas are smaller and lighter, as they don't need the lower frequency elements. The smaller elements are less prone to bird damage, and the antennas are cheaper to produce. But the old lower frequencies travelled better, so many parts of Australia have worse reception than previously. Where I live, when we first bought our land there were 2 stations available, 3 and 6. The signals were great, you could get a good picture with a bit of wet string. Then to clear out bands 1 and 2 they moved ch3 to ch11. trouble was king Island also had a ch11, in clear weather we got co-channel interference, like venetian blinds. the arrival of digital gave us all 5 national channels (each with 3 or 4 sub-channels) but all moved to UHF. We are a long way from the transmitters and UHF doesn't travel as well, and needs "line of sight" reception, doesn't dip into valleys like VHF. So we ended up with really poor reception, albeit of a lot more channels.

After lobbying from out local Council, we were allowed to join the government satellite TV scheme, designed to give satellite TV reception to remote outback residents. We we provided with a satellite dish and receiver, and installation, at no cost. It is great.

Any way, big elements don't give better reception, elements are cut to suit particular frequencies. A higher gain antenna will generally have more elements for a certain band of frequencies than a low gain antenna.