Reception issue - height or length

How can I tell if my problem is antenna height or cable length?

I’m having poor reception (pixellations and weak signal alerts), Tablo TS said the problem could be either the cable being too long (50ft) or the antenna not being high enough. Raising the antenna would require purchasing a mast extension, shortening the cable run would require drilling a hole into the house (and through interior plaster wall). Neither is an easy thing to just try.

Is there a way to determine which it might be, or an easy way to test one or the other?

Not knowing the entire conversation… this sounds a bit off. Antenna height defiantly could be an issue - impact signal strength/reception. Others will likely post more about antenna location and mounting. This of course is dependent upon location, location, location… and actual antenna capability.

As for cable length. My antenna is some 25’ up a tower. I have (recently added) an amplified splitter, on runs anther 10’-15’ split between 2 TVs and a tablo. Back from the amp splitter, a +50’ run to a TV and a second tablo.

According to DTV Reception Maps I am some 40mi form VHF towers - I get clear pictures on all TVs and 95-98% success on the tablo devices.

It’s all wired via quality RG6. I put the power amp splitter in when I add the second tablo. I have “lots of splits” (a balanced 3-way is the way to go over a 2-way, then again with another 2-way) and long runs, no impact on my video quality.

You’ll likely find many here will suggest antenna placement is paramount, presuming you have a quality antenna and cable.

As far as the antenna I have:

One of the stations in my area was moved to VHF-low because of the FCC changes, so I need one that can receive that.

My antenna is located on a mast that extends 4’ above the top of the chimney on a 1-story house.

Here is the channel scan using my address:

Or, if you prefer the FCC the address is 210 Fiesta Dr, 15239

I do have two large trees in my front yard, but they are not in the path of the towers in my area.

I would try a preamp at the antenna before I did anything else.

I comes with a preamp, simple slide-switch. Are the better/different ones?

This isn’t exactly what you’re asking, here’s an old post excellently explaining antenna/distribution amp vs preamp

Ultimately, either can only work with the signal your antenna receives. They can’t actually improve reception of a misplaced antenna.

I figured that, though I’m confused, if the preamp goes close to the antenna, wonder why the one on mine is to go between the 50’ run and the cable that goes into the TV. Seems like they suggest putting it at the wrong end of the run.

I found a mast mount from Channel Master that will add another 2’ to the height of the antenna, though it will also require adding an additional cable as mine is almost at max length right now. But, to properly ground the antenna I would have to add a section anyway so that there is a junction outside the house.

OFF-TOPIC question: Does it make any sense to “aim” a omnidirectional antenna? Seems, at least to me, counterintuitive.

Is one of those actually a power inserter - that you plug into an electrical outlet to supply to the actual amp/preamp ?? They are often shaped.

plugs into wall
white coax supplies power to “power-splitter” it’s an amp splitter, technically distribution amp I guess.

The 3 most important Tablo antenna things, just like in real estate, are location, location, location.
50 feet of good quality RG-6 coax cable can improve overall signal strength, if you can position the antenna in an optimum spot.

Long story…
Raise the antenna, cuz the coax cable is probably not decreasing signal strength much, compared to how much increase in signal strength you’ll get with the antenna in a better position.

Here’s a good article documenting signal loss (attenuation) per 100 feet vs coax cable type:

I also use a 50 foot coax cable between the antenna, and the Tablo.
The cable is RG-6, and this exact one:

According to the chart in the first link…
RG-6 has a maximum attenuation (signal loss) of 5.650 db per 100 feet.
I believe, it’s 5.650 (db)/2 = 2.825 (db) per 50 feet.
Let’s round that off to 3 db for the 50 foot RG-6 coax cable.

It’s true that shortening the cable should reduce signal loss, but there’s a point of diminishing returns that should be considered.

By the way, I originally had this set up…
1 antenna feeding 2 Tablos.
Antop 400-BV antenna inside living room, sitting on top of stereo system cabinet.
4 foot RG-6 coax cable -> coax cable splitter -> 2 - 3 foot RG-6 coax cables
Each 3 foot RG-6 coax cable connected to a Tablo.
No amplifier.
6 channels tuned in with no issues.
Other channels frequently crashed the Tablo.

1 antenna feeding 2 Tablos.
Antop 400-BV antenna mounted on top of 5 foot pole attached to chimney.
50 foot RG-6 coax cable.
No amplifier.
12 channels tuned in with no issues.
Zero Tablo crashes.

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Pretty close, here’s the one I have:

Overall this is a somewhat date web site from the early days of DTV, but the info still valid, there’s a " Cable Loss Calculator" and " Antenna-to-TV Signal Loss" inputting number of splitters

TV Coax Cables and Signal Loss

A butt connection is only -0.5db unless you’re on the fringe you shouldn’t even notice, presuming you properly install the F-connectors.

I’m not sure what type cable it is, it’s the one that came with the 400-BV, plus one that was left behind by the cable company.

image Here’s it’s a power inserter

What is a F-connector?

Yep, that’s it. Has a switch to amplify or not. Is this what you mean by a preamp? If not, can you show one?

I’ll refer you back to my previous post - amp vs preamp. According to the product page link in your first post…image It’s number 2 - that thing in the middle.

There’s also Winegard Boost XT 20dB Pre-Amp for Outdoor HDTV Antennas as an example.

uh, the thing on the end of the coax or the fitting on the back of you tablo or TV

Like off / on :poop:

– Back to your original post, although we aren’t tablo guru tech support… I don’t think many here feel the length of your cable run is an issue. We’ve got runs of +50’ with out a degraded signal.

Antenna height. Maybe… again, not an actual tech support guru - isn’t this a vague generalization?

Here’s my antique antenna on the edge of the woods… picking up channels - cabling and splitting to 3 TVs and 2 tablos.

I believe many of your towers were within < 20mi …but it still needs to be positioned and have a reasonably “view”.

Okay, I think one last set of questions (sorry for all this).

The preamps you showed in the last post, is there a difference between them and what I have that might make a difference, or is any difference going to be minimal with only a 50’ run?

Going to go ahead with adding a mast extender to get it up further. Since this is an omnidirectional antenna, does it matter what direction it’s pointing? I’ve asked Tablo this a couple times, but they never responded with anything other than how to align a directional antenna.

I guess we’re the only ones with no little holiday weekend plans. I’d really have thought others would have made some great suggestions for you as well. I’ve discovered and learn other things here myself.

I showed you those for illustrative as you asked “can you show one?” I do believe offers (high-end) quality products. I know there are a lot of “consumer” marketed products. If you search Amazon antenna preamplifer you get a little bit of everything and don’t really know what you’ve got.

You may be just as well off with an amp at the base, before the long run. NOTE, if you have a preamp, and a power inserted that is there is “electricity” in the coax between them, you cannot put something in there unless it has (forget proper term) DC pass through - but then I don’t know how to power one but not the other?

One product description calls the thing a “power inserter”, here it’s a “Smartpass Amplifier”.

Here’s some positive discussions at Tablo Community forum about Antop antennas 400-B[V] in particular

It’s “marketed” as being having

Multi-Directional Reception

Avoiding omni directional, to make theirs “that much better than the rest”, or not to say there are implied limitations, or just a pointless consumer friendly term. Many general purpose directional antennas aren’t pinpoint just-right-here direction ie) muli directional to some degree I suppose. Being flat, and UVF bars not perpendicular, how can it get signals for “all” directions?

The Antop AT-400BV is a directional antenna not omnidirectional. Looking at the information you provided, it appears that your closest stations are located west of your location. If those are the stations you primarily want to receive, then you need to face the front of the antenna (the smooth side opposite of the mounting hardware) west.

If you are wanting to receive all of the stations listed on your report, then you will need an omnidirectional antenna. From what I’ve seen, most omnidirectional antennas do not work as well for low VHF stations.

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The issue with your reception is that you have “2Edge” (two ridges that rise above your antenna to the towers that are blocking the signal). That will make reception difficult, even for a high gain Yagi-style antenna.

The Antop antenna you purchased is a directional antenna, and has no gain on the VHF elements, making it even more difficult to pickup stations.

Even at 60’ above ground, only two towers are line of sight (WBOA-CD and WQVC). Only 3 drop to 1Edge. At 100’ above ground, only 3 are line of sight (adding WPCB).

That being said, it is going to be difficult to get an antenna to pickup those stations reliably 24/7. And most of your stations are due West, or South/SSW.

I am not saying it is impossible to bring them all in, but it is going to be super challenging.