Antennas Direct VHF Add-On


#22

At least an external tuner can validate the antenna’s own performance independently of the Tablo (or any other DVR). Whenever I set up an antenna for a friend, neighbor, relative or acquaintance, I take my USB tuner and laptop with me to ascertain the maximum antenna performance right at the roof or attic. Whatever tuner is used below in the house, at least the antenna’s reception is verified at the source above and before any distribution of signal takes place throughout the home.

Typically I can compare how every tuner in my home behaves with respect to the measurements taken at the antenna and I can grade them. In most cases I can tell how a recording will turn out based on which tuner\DVR was recording a particular show based on these prior measurements. I know which DVR will give me the best pristine recording to archive in my library of shows. For example, I knew exactly what tuners would give me the best copy of the Downton finale to save. The best tuner (using these measurements) gave me an absolutely flawless recording (no pixelation or hiccup for two straight hours) as if the recording came straight off a Bluray.


#23

I can not evaluate the performance of my Tablo tuners but when adjusting the antenna, I can use the signal meter on my tv setup screen because I can see my tv thru the balcony door while I tweak the antenna. An external meter would be handy. When I was using the distribution amp, I could switch inputs on the tv to use the built in meter, now l have move the coax from the Tablo to the TV.


#24

8[quote=“MarkKindle, post:8, topic:14542”]
Since the house stands between the transmitting towers and the antenna, the antennas in the open may be getting signals bouncing off objects in the area (like the mesh building walls). The CM as omni-directional is positioned to capture signals all around it.
[/quote]

Thanks for pointing me in this direction. Playing with refectors and antenna direction, I found a sweet spot on the building across from me.

I found a broken coax connection on my VHF antenna. After I fixed that, mild pixillation was occuring while my signal strength remained good. Because of the interference, I decided that I needed to move away from the omnidirection Smartenna. So I started looking at small yagi antennas. I looked at the CM Stealthtenna but l liked the looks of the RCA ANT750E. I like the size , the reflectors and the reviews. So far it has increased and helped stabilized my signal strength. Channel signal signal is running from 47 on NBC to 75 on Fox. When the storms get here later this week, I’ll have a better idea about how it will work. I expect some pixcilization in the storms and weather changes but I hope I will not have any recordings dropped for a weak signal. In the mean time the antenna looks good. The Smartenna box look was neat but no class.

I also tried a Channel Master CM-7778 moderate preamp at the antenna mast. It seemed to help a little but it cause pixcilization that went away when I removed the preamp. I ordered the preamp from Walmart. They gave me the best price and knocked off an extra $5 for using their app. They delivered free the next day and I can return it to any Walmart store.

Interesting, my strongest signal strengths are when I point the antenna back at my own building but I also get more pixcilation pointing back at my own apartment.


#25

Storms and “bad” weather can be deceptive. For example, a clear sunny day is one of the worst conditions for OTA. A dark cloudy day is actually the best. I typically experience the best reception on cold, dark, cloudy days (even with rain). Summer heat, humidity and sunniness is the worst for me!

RF waves will bounce off clouds and low atmospheric conditions whereas they may get “lost” on bright sunny days that have a “high ceiling.” My best reception is usually from October to March. Then when spring hits followed by summer I lose up to 20% of signal strength.


#26

Okay, first test by fire. Heavy rain, dime to quarter sized hail, 60 mile an hour wind and the emergency sirens sounding because of a tornado alert.

Viewed video directly from the TV only connection, good signal strength but heavy pixilation and slured audio. The captions were good so I could follow the story. Switching to live tv from the Tablo, difficulty getting a lock on the signal, then heavy pixilation and slurred audio with good captions. Once a lock on the signal occurred, video improved as the storm let up. When the rain slowed down, I went out and tapped on the antenna to shake off the heaviest water and the video went to good with very minor pixilation. 90 minutes after it started, I have a light rain and an acceptable picture. No dropped recordings. I like this litte antenna. It comes with hardware for mounting it in an attic.


#27

Starting to think about capturing a reflected signal instead of getting a stronger signal is interesting.

Because I don’t have a line of sight to the transmission towers, It looks like I’ll have to rely on getting a reflected signal from the buildings across from me and the sweet sport for the strongest signal can vary slightly for the marginal stations, I may need to periodically check my signal strength. I lost my H&I station today and had to make a small adjustment to the antenna to get the station back. Being able to step out on the balcony and tweak my antenna while I am looking at the channel strength meter on my TV will be handy. I have routed the antenna back through my distribution preamp so I can change the input selection from my Tablo to the meter on my TV with the TV remote. Until now I also have been able to aim my antenna at single spot to capture the signal reflection and leave pointed at that spot.

I have weathered my first storm, now I am wondering how I will fair with the cloudless skies of summer. How much will this impact my reflected signal.


#28

Storms tonight, south by the transmission towers. ABC strongly pixilated, almost unwatchable. I had put an extension on my mast and moved my VHF add on above my RCA ANT 705E antenna, where it belongs. No major issues for the rest of the channels and I had no recordings scheduled for ABC. ABC cieared up after the storm passed through. I had moved my antenna back to it’s previous location. I hope that I can leave it there but thoughts keep popping into my mind. Thankfully there are only so many things that I can do on a 5’ by 17’ balcony.

My major accomplishments seem to be no segmented recordings during the storm and the signal strength seems to be stabilized since l found the loose coax connector on the VHF addon antenna.

If I have a problem with one channel then ABC is the best one because I can watch missed shows next week on the ABC Roku App.

I just would like to have the best picture that I can get in my situation. Hopefully it is minor tweaks now.

Several issues that I thought might be Tablo or Roku issues have cleared up since I started adjusting things.


#29

The way channels behave during inclement weather can be puzzling. For example, one of my strongest channels also pixelates the most during a storm. I guess it depends upon the frequency and how certain frequencies interact with storm conditions.

I’ve been tracking the comments of CM’s newest antenna the Smartenna+ (not the Smartenna which is completely different) with its “beamforming” technology. Very positive reviews. You might want to test this one out given its 30 day return policy. This antenna takes a different approach to signal scattering from traditional antennas.

With the Smartenna+ you might not need to put it on your railing. Instead attach it to the wall (exterior) of your balcony. Theoretically this antenna is supposed to find the all the best angles of the all the signals within a wide sweep. Which might take care of the reflections you have to work with…

It also comes with a built-in CM amplifier that has a very low noise figure.


#30

I thought about the Smartenna + as a replacement for my Smartenna but signal strength does not seem to be my main problem. I thought that I might be getting too many signal reflections in my courtyard. With the small RCA Yagi, my signal does not fluxuate more than a few db where some stations (mainly low VHF) previously on the Smartenna had wide fluations. My strength strength can vary from day to day but usually remains strong after small adjustments in the antenna direction. I opted for a more focused reception with daily minor adjustments. Because of my lack of knowledge I have to rely on trial and error. I have easy access to my tv’s builtin signal meter.


#31

I think that the Smartenna+ is meant to do signal corrections. In other words it tries to determine, in a multipath environment (overlapping reflections), which signal to use. Or to determine which signal out of a possible set will give the best reception for that particular channel.

Also from what I’ve read, it attempts to resolve multipath issues by “combining” separately arriving signals and\or differentiating them when they can become mutually destructive by picking out the required frequency.

I can’t vouch for these signal adaptation strategies but I’ve seen them at work previously in certain kinds of amplifiers that attempt to select a signal from a competing array of signals.

If ever the daily adjustments become too much work or bother, you may want to try this antenna and see whether it can make those adjustments for you. As in your case, it is the constant signal adjustments through antenna placements that drive people crazy. CM is smart to try and address this aspect of antenna placement because of daily signal variability though whether it truly works has yet to be determined. I don’t quite know how to evaluate all these reviews - if those who have purchased it had the problems you describe above.

I know how beamforming works with Wifi routers but haven’t been able to get my mind around beamforming in the case of television. These two cases are different.


#32

Thanks for all your suggestions. They have been helpful and thought provoking. They have got me thinking of different directions and other options. I’ll keep an eye on the technology. If it shows promise, I’ll keep it in mind. Especially in the next evolution. The real stumbling block for now is that right now it is an inside antenna and I am in a stucco building wrapped in wire mash. I’ll try to live with what I have for now unless I have to move in an other direction. I am curious how what I have will work in the long run, especially as the trees grow. I still keep playing with it and probably making small changes.

It’s been fun. Thanks for getting me this far.


#33

That’s why I suggested it be mounted on the wall outside the door and under the balcony above you to protect it from the rain, rather than on the rail.


#34

Thanks.


#35

Moving the CM-3414 outside to the mast seemed to slightly degrade my Vhf reception.

I removed the vhf dipole addon and finally wound up with my RCA ant705 antenna, CM-7778 Medium Gain Amp and CM-3414 distribution Amp before the tv to split the signal. One output to the TV antenna input on my tv for watching live tv and trouble shooting . One input to the Tablo. It has been running for about a week with a good signal, but only time will tell. I think my antenna positioning got me past any multi path issue since I have no line of sight to the transmission towers and I hope the boost in the signal will allow some tolerance for fading in the reflected signals, since my sweet spot on the building opposite me tends to shift slightly. My Vhf station is the weakest portion of the signal and Fox 5(35) is on the verge of being so strong, it could go black. I have no idea what I am talking about but I have been doing some reading and had some help. Multi-path signals, RF channel, attenuator, impediance, daisy chaining amps. All a foreign lanquage. I just kept changing and moving things until it worked. I appreciated the suggestions.

I plan on trying to be hands off for awhile.


#36

Apparently the Smartantenna + does not make adjustments to adjust for changing conditions. It has a button that you have to push to do a rescan, just like you have to activate a rescan manually on the Tablo.