All posts tagged antenna

Mohu Sky 60 on the apex of our roof

Mohu Sky 60 on the easternmost apex of our roof

This is our new Mohu Sky 60 antenna, suitable for indoor or outdoor use. Its design is based on a mudflap antenna developed for covert military communications by Mohu’s parent company, GreenWave Scientific.

Mounting it in the attic is difficult in our house due to our vaulted ceilings. It’s hard to reach a good place in the attic to hang the antenna, then to get the cable down to the TV. You also lose some of the signal every wall it passes through.

I wanted the maximum signal strength, so an outside mount as high as I could get seemed best.


I didn’t feel that the risk/reward ratio favored my scaling the steep roof to install it, so I hired help. Even the installer had qualms about clambering up there.

The Sky 60 comes with a filtered amplifier (powered by either USB or wall wart), mounting bracket, a short mast, and a 30′ RG59 cable.

RG59 is the lighter, more flexible kind. RG6 is the thick, heavy-duty one that the cable company uses. The installer was very down on RG59, even wondering if it is still made. Yes, it is. And it does quite well for indoor use and short runs. But I agreed with him that RG6 was the best choice for an outdoor installation.

(Click to enlarge)

(Click to enlarge)

I was able to save him time, and therefore me money by reusing the existing cable to our den, which I had traced to the cable box a week before. (After I did that, I hooked up the Sky 60 outdoors and hung it on a couple of nails at my highest reach for a few days to try it out, with good results.)

Once he got the mast in place, I did a Will Rogers and hurled a coil of the RG59 cable up there like a lasso. To my utter astonishment, I scored a ringer on the first try.

He lightly attached the antenna to the mast, and I connected up the cable temporarily so I could go indoors and check signal strength on all the stations with various antenna orientations.

To finish up, he tightened down the screws on the antenna, attached RG6 cable, and used a tall ladder to fasten it down the side of the house. He then grounded the antenna properly.

Indoors, I had already connected the TiVo tuner to the existing cable wall outlet. The Sky 60’s USB power cord connects to one of the TiVo’s two USB ports. (I use the other one to power a little LED clock, needed to show us the time with the cable box gone.)

The Sky 60 seems well-suited for a rural setting, where there is a lot of distance (as many as 60 miles), and a clear path to a distant antenna farm.

However, its compact, ultra-wideband design makes it an excellent choice for suburban areas like ours (81st & Memorial).

I want my RSUTV!

A majority of Tulsa-area antennas are located in Coweta and Oneta, 12-15 miles east-southeast of us. That’s close, but our street slopes down and away from them. That’s why I wanted to go as high as I could get.

But there are also tall trees in our immediate neighborhood between us and those antennas.

As I learned previously (High winds can affect TV reception), the higher frequency stations are more often affected by trees and the movement caused by wind. Those shorter wavelengths are close enough to the size of tree trunks and branches that the signals are more easily blocked or diffracted.

Tulsa-area TV transmitter locations

Tulsa-area TV transmitter locations from our house. See

The standard advice is to point your antenna right at the antenna farm and hope for the best. That was the advice of the installer as well. We tried it and it worked.

But I also wanted to pick up KRSU-35 (RSUTV) in Claremore, to our northeast. It wasn’t happening with that orientation.

So I had him fudge the direction to slightly north of east, toward a low-tree corridor through our neighborhood. I still got high signal strength from almost all the other stations, but also a consistent signal and picture from Claremore.

The Sky 60 is billed as multidirectional, and it is, but its orientation made a critical difference in receiving the Claremore station, which is almost 30 miles from us.

We have been very satisfied with our reception of all the area stations, but one…

The Riddle of COZI

KWHB-47/COZI-47.2 (Independent, real channel 47), one of the higher frequency channels, occasionally freezes and not infrequently suffers brief, blocky blotches of pixelation on the screen. But KOTV-6 (CBS, real channel 45), close to COZI’s frequency, is rarely affected. Both of their antennas are in Oneta.

The signal strength we get for COZI is about what we now get from RSUTV, both on the low side of the acceptable range. KOTV and all the other channels in the Tulsa area (excluding KDOR, way up north in Bartlesville) show high signal strength as measured on the TiVo’s tuner.

(Click to enlarge)

(Click to enlarge)

The chart at right is custom for our street address and free from TV Fool.

It shows that KOTV’s “Noise Margin” (a rough estimate of signal strength, based on the topography of the area) is 65.3 dB, whereas COZI’s is 51.9. It’s lower, but not that much lower (KRSU is 26.4).

It also shows that the COZI and KOTV antennas must be either side by side or on the same mast!

The full wavelengths of the KOTV and COZI signals are between 17.5″-18″ so they would seem to be equally vulnerable to tree interference, and should behave very similarly.

By contrast, I have a flat amplified antenna taped to an east-facing inside wall in the theater room. I found one and only one spot on the wall where it works. (I could find no spot near the den TV where a flat antenna worked acceptably. That’s why the Sky 60.)

The flat antenna in the theater room does a better job with COZI than the outdoor antenna in the den, but worse with RSUTV to the northeast. That makes some sense, because the flat is aimed straight east, slightly more toward COZI and slightly away from RSUTV compared with the Sky 60.

But COZI’s signal strength on the theater room set, like KOTV’s, measures near the maximum, and pixelation occurs far less frequently, though high winds can still affect COZI’s picture in there.

Why does that antenna/TV tuner show maximums for both KOTV and COZI, but the Sky 60/TiVo combo reads a maximum for KOTV, yet much lower for COZI?

It’s a bit of a puzzle:

  • Are we getting a freak “bank shot” of COZI’s signal in the theater room, or finding a gap in the tree cover?
  • Is the compromise angle of the Sky 60 critical for COZI, but not for any of the other stations at precisely the same location?
  • Is even minimal tree movement periodically pushing COZI over the “digital cliff” despite my seeing steady signal readings?
  • Maybe the KOTV antenna is higher on the mast as well as having more power?

Since a small shift of the Sky 60’s angle was decisive in getting a consistent picture from RSUTV, might that same shift might have been decisive in losing a consistent lock on the lowest-powered (though not by much) signal at nearby Oneta?

Maybe not; new info: I did some digging at for KWHB (COZI) and KOTV data.

Key facts: both stations are indeed on the same tower and KOTV is 113 meters higher than KWHB. That’s 124 yards, more than a football field.

But here’s the eye-popper: KOTV broadcasts at 840.1 kW ERP (effective radiated power). KWHB at 50 kW ERP. Huge difference! No wonder KWHB has a harder time blasting through the tree clutter.

Re the misleading (at least to me) “Noise Margin” figures quoted above, TV Fool’s TV Signal Analysis FAQ states: “Please understand that this is a simulation and can only be treated as a rough approximation. Reception at your location is affected by many factors such as multipath, antenna gain, receiver sensitivity, buildings, and trees – which are not taken into account. Your mileage may vary.” Did it ever!

The mystery now is how I am getting a strong signal in the theater room, but only when the antenna is at a particular spot at the center and top of the wall.

It appears to me that the offset position of the theater room vis-à-vis the den gives it barely enough clearance from the trees to avoid impairment of COZI’s signal, at least at that one little spot. I wish I had “radiovision” so I could see the radio shadows and reflections in there.

We haven’t yet experienced the blooming of trees in the spring with the Sky 60 on the roof, so we’ll soon see how or if that affects our reception.

Luckily, COZI is more my channel than Gaye’s (it has “Run For Your Life“, which I record with my WMC/Pi setup in the theater room), so this isn’t a big crisis. And it is watchable a lot of the time.


As I had previously found (Placing an indoor TV antenna), you need to experiment with inside antennas for best performance. The same is true for outdoor or roof mounts. It’s difficult to predict where the best spot is going to be, and it is often surprising.

Experiment at leisure with different antenna orientations and positions on an inside or outside wall, or in the attic, and find out what works best at your house. Then you’ll be better prepared if you choose to do an outside mount.

When the stations you want are not all clumped together, tweaks and trade-offs may be necessary.

I had hoped that maximum antenna height would completely eliminate reception problems.

It almost did, but I had to tweak the direction to pick up a distant desired station (RSUTV) while keeping the others.

Sometimes-impaired reception of COZI may be the trade-off, but given its low power and our tree-laden, partially-obscured location relative to its antenna, COZI would likely be problematic for any antenna in the location I selected, regardless of its orientation. (I seem to have barely caught a gap in the trees with the theater room antenna’s precise positioning.)

I learned that two stations (RSUTV and COZI) received at roughly the same signal strength, albeit on the lower side of the acceptable range, can differ greatly in quality. One can come in consistently, and the other can be subject to frequent interference if it is on a high frequency and nearby trees are in the path.

Signal strength as measured on your TV doesn’t always tell the whole reception story.

(This guy had better luck placing his Mohu antennas in and near the basement window to pick up reflected signals! He also found a way to combine two antennas.)

Final notes

The Mohu Sky 60 is doing a bang-up job for us. It’s solidly constructed and was light and easy to move around in the experimentation phase. I like the unique appearance of the antenna up there; Gaye thought it looked like an alien artifact (which is to say she likes it a lot).

With the TiVo Roamio OTA DVR/tuner and the Mohu Sky 60, plus Netflix and Amazon Prime, our TV cable cord is well cut.

According to my calculations, we will save about $1750/year! And we didn’t even have any premium channels like HBO, etc.

(Full disclosure: Mohu sent me the antenna for free to review.)

I noticed a crawl on KOTV this morning:

“Attention DISH subscribers: KOTV News On 6’s parent company, Griffin Communications, has been negotiating with DISH on a new carriage agreement.

“If negotiations are not completed before January 15 at 6 p.m., you will not be able to view News On 6 on DISH Network.

“This means you will not be able to see local news and weather from News On 6, CBS programming such as NCIS, Big Bang Theory, the Young and the Restless or the NFL on CBS.

“We hope to reach an agreement but feel it is important to alert you in advance.”

News On 6 = 6?

“News On 6” = Channel 6?

I find the usage of the “News On 6” phrase confusing. The entire channel is referred to as “News On 6”? I think they are just saying Dish subscribers will not see Channel 6 at all, no local programming, no network programming.

But how about KQCW, also owned by Griffin, and sharing some programming with KOTV?

To clarify the relationships of the various Griffin entities in Tulsa (I hope):

The main KOTV CBS-affiliated channel is on channel 6.1 broadcast (6 or 1006 on Cox). Their 24-hour news repeater channel is “News On 6 Now”, channel 6.3 broadcast (53 on Cox). is the main KOTV website URL, which encompasses not only the main channel, but also the repeater channel and sister station KQCW. TitanTV program listings are displayed for 6.1, 6.2, 6.3, 19.1 and 19.2 (thisTV).

KQCW (seen on both 6.2 and 19.1 broadcast, 12 on Cox) has its own separate website,, though it also functions as a second home for some of KOTV’s local programming (e.g. “6 In The Morning”).

A page explains: “…when News On 6 breaks into regular programming for breaking news or severe weather we will move CBS and syndicated shows to News On 6 Now.”

I’m not sure what it all means with respect to the Dish dispute; perhaps nothing. Maybe less prose-addled, better-informed readers can comment.

In any case, since cord-cutting is the focus of this blog, I will point out that all KOTV subchannels are available for free over the air. All you need to do is put up an antenna (e.g., the Mohu Leaf, Curve, or Sky 60) if you have a TV manufactured in the last 10 years. You can use this along with cable or dish.

While looking into the dispute, I saw that Rupert Murdoch’s News Corp is in a similar negotiation with Dish. Dish has already blocked out Fox News and Fox Business due to the impasse.

According to this Hollywood Reporter article, News Corp is trying to use access to the popular Fox News Channel (along with the less popular Fox Business) to pressure Dish into carrying its fledgling channels, Fox Sports 1 and the FXX Network.

Each corporation is headed by a stubborn and powerful individual (Charles Ergen is the Chairman of Dish Network, and largest stockholder; see this eye-opening AOLJobs profile), so this could drag on for awhile.

Dish presents its side of the dispute on their website, News Corp has

To quote a Groucho Marx character (Otis B. Driftwood), “Hey, you big bully, what’s the idea of hitting that little bully?

Here is a Wikipedia page about the general topic of Carriage disputes.

So, what is the basis of the “News On 6”-Dish dispute? Is it strictly the price of carrying the station(s)?

Here is a comment from News On 6’s page about their previous dispute with Dish in January 2011, Attention DISH Network Subscribers: “Griffin Communications has agreements with every cable or satellite system and we have never had any issue negotiating a fair price for our service.” Is 2015 just chapter 2 (or higher) of the story?

Tulsa-area TV transmitter locations

A couple of days ago during high wind conditions, I moved our den antenna around while tuning in the stations located to the east of Tulsa, near Coweta. (Generate this map for your location on this page at I get excellent signal strength from all of these stations.

But some were affected by the wind. This is due to the movement of trees between my antenna and the transmitter.

Comparing my results with the data in the chart at bottom (click to enlarge), I observed that the stations with signal readings unaffected by wind were lower in frequency. The stations whose signals intermittently dropped to zero were higher frequency.

This is understandable. The higher the frequency, the more “line of sight” it is. High frequency FM radio has a much shorter range than low frequency AM for this reason.

Our “legacy” channels are KJRH-2, KOTV-6, KTUL-8 and KOED-11. Their antennas are roughly in the same place to the east (8 is a few miles away from the others).

When these channels went on the air in the 1950s (KOTV in late 1949), channels 2, 6, 8 and 11 were all VHF channels, on the lower end of the frequencies allocated for TV by the FCC.

Of those four, only KOTV-6 reception was affected by the wind. Why would it be different from the others?

It turns out that KOTV is the only one on a high frequency channel, despite its low number.

In Tulsa, we didn’t have any higher-band UHF channels until the 1980s (with one brief exception in 1954, KCEB).

Today in the digital era, there are lots of channels across the VHF and especially the UHF band, and most have subchannels.

For technical and administrative reasons, the need and desire was there for some stations to change frequencies. But it would be confusing for KOTV, billed as Channel 6 for decades, to show up on your TV as channel 55 (where it was in 2004), then channel 45, where it is today.

A way had been developed to let KOTV remain Channel 6. Though KOTV broadcasts on real channel 45, it has an alias of channel 6, its “virtual” channel.

During the transition to digital, real channels were shuffled around, but viewers continued to see 2, 6, 8 and 11 (or in the new subchannel nomenclature, 2.1, 6.1, 8.1 and 11.1).

Currently, virtual channel numbers 2, 6, 8 and 11 are assigned to real channels 8, 45, 10 and 11, respectively (only 11 has the same virtual and real channel). Virtual 6/real 45 alone is up in the high frequency range (see the table below).

Thus KOTV is the one of the four more vulnerable to dropouts in high wind conditions (at least as seen by my antenna from my house). If it bothers me enough, I could move my antenna to the attic, or outside on a high mast.

Generate a custom data page for your own location at this page on (To help interpret it, use this FAQ at tvfool.)

The maps and tables are a great help when you are looking for your house’s sweet spots, and understanding why they are where they are.

Data for local channels from our house

(Click to enlarge) Local channel data for our location. The higher the real channel, the higher the frequency.

Tulsa-area TV transmitter locations

This little map is based on my location near 81st and Memorial. (You can generate a version for your location on this page at

As you can see from the labels I added, almost all the network stations and their subchannels are located to the east-southeast near Coweta. They are 12-16 miles from us.

Unamplified indoor antennas should be adequate for most stations within 30 miles or so. KRSC-35 (now KRSU) north of Claremore is just under 30 miles from us.

But there is a caveat. Where you  place an antenna within your house can be critical for best results, and requires experimentation to find the best spot(s).

There was exactly one spot in our theater room within range of one antenna’s cable that worked well for almost all the stations. It was in the middle of the wall, east-facing, and as high on the wall as it could get. Surprisingly, this wall is an interior one.

In the den, I taped a flat antenna directly to the inside of an east-facing window.

Be prepared for surprises when you move your antenna around, because the interior structure of your house (especially wiring and metal), and exterior buildings and trees affect reception by creating radio wave reflections and blank areas.

The best placement may be counter-intuitive. It might be flat on a table, or facing a “wrong” direction.

Some placements are forgiving. Some have problems with particular stations. In our den, the chimney is between the antenna and the channel 44 transmitter to the southwest, which blocks it pretty effectively.

The map above can help make sense of why some spots work and why some do not.


Tablet cam pic of me and my “client”, auto-uploaded to our home Plex server, ready for big screen display.

To date, we have:

  • Replaced cable landline phone service with a refurbished Ooma (cost is now only $4/mo in taxes), then bought a $15 used modem to save a rental charge of $7/mo added by the cable company because of the switch.

  • Taken internet service down to “Essential” level (saving $15/mo) without impairing our streaming Netflix.

  • Removed 2 out of 3 cable boxes (saving $17/mo), replacing one with only an indoor antenna, the other with a $35 digital converter box and antenna, and,

  • Hooked up cable directly to the 2 sets to get analog cable channels (a minimum of “Essential” level TV service is required).

  • Eliminated three tiers of TV service over a 2 year period (saving $30/month), bringing us down to Essential level, similar to the old basic and extended cable.  We still have “Advanced TV” for about $3/mo extra, required for DVR service (at an additional $12/mo). The only channels gained from adding Advanced on top of Essential are music channels. You also do not get HD without Advanced TV. Tricky price and service structuring.

  • Added another Roku box (in the bedroom) to stream Netflix, Amazon Prime Video, free Crackle, and our own media on Plex. Tried Hulu Plus, but it wasn’t worth it for us.

  • Added a number of Android remote control apps to my wifi-only smartphone.

  • (Tech talk alert!) Added a used bottom-of-the-line Windows 7 computer (thanks, Mom) with included Windows Media Center (WMC) software. With USB TV tuner plus antenna, acts as a DVR for broadcast TV and uses free ServerWMC software to stream to a $35 Raspberry Pi computer connected to the large TV in the theater room. Win 7 also runs Plex Media Server software to stream our local TV/movie content (mostly ripped from DVDs) to the Pi (running PleXBMC beta software over Raspbmc), and all Roku boxes (via the Plex Channel).

  • Added inexpensive enclosures to 2 unused hard drives to let them serve as external storage for digital content.

  • Previously negotiated a $50/month cable bill reduction for a year, followed by another $10/month reduction after all the above steps were done. You can bargain more effectively if you show the customer service rep that you have done your homework and are ready to act.

The bill is down from $215/month in April (TV/phone/internet) to $133/month (TV/internet) currently. That’s an $82/month, almost $1000 savings over the next year. The low-hanging fruit has been picked.

All these actions were expensive only in the time and effort it took to figure them out and make them happen, not in $$. I learned a lot, too, which was very satisfying.

(If my seeming obsession with $$ has suggested that we are in straitened circumstances, such is not the case. I get a kick out of seeing how much I can do with “found” and inexpensive resources, and cutting costs with minimal or no pain.)

Internet is a must-have. But we could save another $1000+/year by cutting the TV cable entirely.

To do so, a minimum WAF (wife acceptance factor) requirement would be reliable, user-friendly broadcast TV DVR in the den (my wife’s “office”).

Here are some improvements, combinations of which could make that possible. Each one could entail significant expenditure and/or handyman skills and tools:

  • Wire the house for Ethernet.
  • Put up an external antenna.
  • Add an HDHomeRun networked digital TV tuner.
  • Add Tivo-type product as broadcast TV tuner/DVR.
  • Add a Simple.TV box
  • Add a computer with HDMI output.

Which combinations?

One of the simplest ways to go is with an indoor antenna (we might need an external in the den; our reception isn’t perfect there), and a Tivo Roamio for live broadcast TV/DVR. However, there is a Tivo fee of $15/month.

We do have two other rooms where an indoor amplified antenna suffices. An HDHomeRun tuner could be placed in one of those rooms. Then Ethernet wiring could deliver the broadcast signal and DVR recordings to a computer ($35 Raspberry Pi or Windows 7/8 PC, or somewhere in-between) attached to a den TV via HDMI. That is one way for us to avoid both an external antenna and monthly fee.

Simple.TV combines some of the virtues of each setup. You attach an antenna and an external hard drive for DVR recording. It connects to your network via Ethernet. View over the Simple.TV Roku channel. Monthly fee is $5/month. Here is a 9/22/2014  Wired update on Simple.TV in comparison to Tablo DVR and Channel Master DVR+.

(I have considered replacing the TV in our den, a 2002 vintage 36″ flat tube HDTV without digital tuner, since it can only handle component, S-video and composite video inputs, not HDMI. To get around this, I have tried two different HDMI-to-component video converters without success. An HDFury Gamer 2 Component likely would work, but at a cost of $160, I may hold off until I reach a decision. Simple.TV would not require a converter.)

The cord-cutting crux of the matter remains: can we (especially my wife) do without the Essential (aka basic and extended) cable stations. If we can’t, then none of the above would enable us to cut the TV cable.

The most we could cut would be “Advanced” DVR/HD service, keeping only analog, saving about $15. And analog is an unadvertised feature that could go away at any time as the cable service evolves. Not a huge reward vs. the cost of bringing broadcast TV DVR to the den.

Of course, there is the “TV gypsy” path, moving from cable to dish and back every year or so to get special new customer deals. But by going away for at least 30 days, you become eligible for the deals. You could use Roku and broadcast TV to “survive” the 30 days. Maybe you could survive a lot longer.