My Gray Hoverman

It should be noted first and foremost that I am not an antenna design expert. I have tried to explain how this antenna and the Mclapp antenna work, but left the real technical details for others to explain (try googling). I have just taken what has been designed, modeled and successfully used in the field, and applied it to my situation. If you want greater understanding of how this antenna and the Mclapp-4 works, please goto digitalhome.ca, and there is a whole forum section dedicated to OTA antenna design. Formidable users are 300ohms, stampeder and mclapp among others.

What does SBGH stand for? What does DBGH stand for?

SBGH stands for Single Bay Gray-Hoverman. DBGH stands for Dual Bay Gray-Hoverman.

So now the question is: What is a Gray-Hoverman?

The Gray-Hoverman (or GH for short) is a DIY antenna for picking up television broadcasts in the UHF (Ultra High Frequency) spectrum. It is not uncommon for the big TV stations to broadcast over-the-air (OTA for short). This has been going on since the beginning of television. The common would be to broadcast analog signals in the VHF region. Now that going digital is mandated in North America, majority of the stations are starting the switch over and are broadcasting digital signals in the UHF. For the big broadcasters like NBC, CBS, ABS, Fox (in the states) and CBS, CTV, Omini1/2 up here in Canada, these signals are in HD. If you can get a clear, strong signal, the advantage over satellite or cable is a better PQ due to the fact that the data over those latter media types is highly compressed to meet bandwidth requirements. Also, it is far cheaper than paying the huge monthly costs to satellite or cable providers.

There are many great commercially offered antennas for picking up OTA-DTV. Two excellent antennas that come to mind are the Channel Masters 4221 and 4228 antennas. These are Single Bay and Dual Bay types, based on the bowtie technology. Back to the Hoverman, a Single bay antenna consists of a single elemental pairing, where a Dual bay consists of two sets of elements joined together to increase gain. The Gray-Hoverman, if built properly, can out-perform their equivalent commercial antenna and there are tests that support this.

DESIGN

My design is basically a copy from one outlined on this website:

http://www.casano.com/projects/hoverman/index.html

A ton of information on the Gray-Hoverman, and just in general OTA can be found at this website:

http://www.digitalhome.ca/forum/forumdisplay.php?f=81

Look for guys by the nicks "Stampeder" and "300ohm" as they have a wealth of information and are more than willing to lend a hand. Actually everyone on that forum site are very helpful.

I don't have a true ATSC tuner currently but I'm looking at a Hauppauge HVR-1250 PCIe x1 card. Unfortunately I don't have to many other means of testing, and have to rely on all the current data available.

I hope to be able to install this SBGH in the attic and pointed towards the CN Tower to get a few Canadian channels. I will also use it to experiment in getting some American channels from Buffalo Long Island area. Eventually I will build a DBGH (Dual Bay), installed in the attic pointed towards Buffalo, and use a two antenna system to get all the free TV required.

This is the current design for my two Gray-Hoverman builds:

The two zig-zag elements are 10AWG copper electrical wire. Home Depot sells cut to length 10-3 Dryer wire for under $4.00/m (cdn).

The 1"x2" Mesh is 14AWG galvanized fencing from the TSC outlet, it was about $50 cdn for a 50 foot roll.

The balun used was a RCA type that is sold at Home Depot for under $5.00 cdn

Well here are a couple of shots of my first Gray-Hoverman using window screening as a reflector:

For this build I used 10AWG wire as I had difficulty finding 8AWG solid. I'm also going to experiment with using wire window screening that I had laying around the house. The total cost of this project was around $35. The next step will be to take it over to either my parents or the in-laws. Each have an ATSC tuner built into their LCD screens. If those test are successful, then I will be looking into getting a tuner card and try it out here.

You can view my target locations on the OTA page.

LOG

*19/9/09*

Today was the first test of the Gray-Hoverman. I took the antenna over to my parents house since they have an ATSC tuner in their LCD TV. With the antenna inside the house, leaning against a wall in the general direction of the Canadian feeds based out of Toronto, I was able to pick up some analog VHF channels, though they were very snowy. This was expected as the GH is a UHF antenna, so I was a little surprised to even have picked them up. I was able to pick up both OMNI's, CTV, TVO, Global, CityTV and CBC (French), though most were snowy, they were still watchable. What I really liked to see was that CBC-HD came in crystal clear, even though the signal strength meter was around 50%. This excited me as the antenna was leaning against a wall, sitting on the floor, around the middle of the house. The signal that it picked up had to go through trees as well, so the fact that I was able to get a channel that clear was really exciting.

I then pointed the antenna towards Erie, to try and pick up CBS, ABC, NBC and Fox, but was unsuccessful. I still picked up most of the Canadian feeds though, which led me to believe that the mesh screen used was pretty futile and it was not reflecting the signal at all, but made the antenna appear to be reflectorless, or bi-direction. So before my next test, I'm going to change the reflector to a solid foil type, broke in two halves. That recommendation is from Stampeder on the digitalhome.ca website.

Finally I pointed the antenna towards the Buffalo feeds. This way I still picked up the majority of the Canadian feeds, but in addition, I picked up CHCH's digital HD feed, and a Christian analog and HD feed. Both additional HD feeds were cyrstal clear as well. But I wasn't able to get any Buffalo feeds.

All in all, these test were very encouraging and promising. It showed that the Gray-Hoverman antenna was very reliable in getting signals, even in a poor position. Now to refine the design by fixing the reflector. Then get ready for the second set of tests at the in-laws. The mounting will be the same idea...just leaning it against something, but with a different reflector, we'll see what good fortunes that brings.

*26/9/09*

I made some changes to the antenna by replacing the thin screen with a solid foil background. Below are a couple of picks with the updated reflector.

The antenna is as ugly as you 'd ever see one, but it was able to pickup the following transmissions at my in-laws house. Again this was just sitting on the floor inside the house. So the signal had to go through exterior walls, and mature trees all around.

Pointing towards the CN Tower, I picked up a total of 18 channels, six of which were HD. The HD channels were:

CBC-HD, SunTV, CHCH-DT, Global-DT, CTS-HD, OMNI2-DT. Though with the antenna pointed in that direction, SunTV was only 20%, and CHCH was very low, so both those channels were breaking up. CBC-HD was around 90%-100%, and all the others were about 30%-50%, but the picture was still good. In addition, I also picked up the following channels:

5 - CBC, 9 - CTV, 11 - CHCH, 19 - TVO, 25 - Global, 36 - CTS, 47 - OMNI1, 57 - CityTV, 69 - OMNI2. All these channels were a little snowy, yet majority were still watchable.

Turning the antenna towards Buffalo, did not give me anymore channel, but I lost a few. CHCH-DT and SunTV signals were very much increased. Experimenting by turning the antenna towards Erie, still did not give me any channels, and lost even more of the ones I had before.

In turning the antenna back towards Buffalo, I raised it a little higher. CHCH-DT and SunTV signals were alot stronger, and I even finally picked up WNLO-DT (23.1 - CW23). The strength was around 40%, but the signal was clear to watch. My first Buffalo station finally. Now I can only imagine what I'm going to pick-up, once the antenna is in the attic. Getting that Buffalo station also gives me the incentive to possibly build a DBGH in the future. I'm also going to strongly look at picking up a tuner card for the computer now after this successful test. What was especially nice was watching hockey in HD...SWEET!

*6/10/09*

Since picking up the HVR-1250 for the HTPC, I've continued to experiment at my house. Placing the antenna in the livingroom, leaning it against a wall, allowed me to get CHCH-DT, CW23 (WNLO-TV), and SunTV (sometimes). I wasn't able to get any transmissions from the CN Tower...but then realized that the location would have to go through two brick walls, and the neighbors house...small wonder why I wasn't getting them. So I tried the antenna out in my kid's room. This room is directly below the attic location I intend on installing the antenna for CN Tower pickup. Leaning it against a wall, transmissions had to go through external aluminum siding, not to mention the corner of my neighbors house could still be in the way. Regardless, I was at least able to pickup CBC in HD pretty good. This angle still allowed me to pickup CHCH too. I also picked up a slew of analog stations. I finally pointed the antenna towards Buffalo again, and was happily surprised to get PBS Buffalo (WNED 17.1 (HD), 17.2 (SD), 17.3 (TH)), WNYB-DT (26.1 (SD) and 26.2 (HD)), along with WNLO (23.1 - CW23). CHCH-DT (18.1) was clear and so was SunTV (15.1).

I'm going to experiment some more with the antenna in the kid's rooms...as they are below some potential attic mounting locations, so if I can pickup some decent channels...I'm hoping the extra height will only help. I'm really hoping to get more stations from the CN Tower though...I hope I can as that's what this antenna was intended for...and then build a DBGH for the Buffalo stations.

*19/10/09*

This section may become more generic and called the Gray-Hoverman instead of the Single Bay Gray-Hoverman. Since last testing, I have torn the Hoverman antenna down. The solid reflectors are currently off and I've narrowed the long outside verticals. These verticals will be used for installing rod reflectors. I have also widened the element spacing from the original 44mm (~1.75") to ~100mm (4"). This Hoverman is also being modified to become a Dual-Bay (building a second element section), and will be used to pickup the fringe Buffalo channels.

This also gave me a chance to do a comparison test with the reflectorless Mclapp-4 antenna build. When first hooked up, I didn't get ABC, which the Mclapp did get. Thinking the design was flawed or there was a problem with the materials, I tried the Mclapp again, to which it didn't get ABC either now. So I knew that it was something atmospheric. Later in the evening, I picked it up successfully with the Hoverman, but lost it again during the course of the night. It will be interesting to see how the dual-bay works out, even though at first, it too will be reflectorless.

*20/10/09*

I'm a little confused. I've built a SBGH, and a M4, both are reflectorless (just haven't installed reflectors on either yet). Both behaved very similar during testing...picking up basically the same channels, with the same signal strengths in the least ideal locations (living room out the window). Last night I constructed a second GH, and stacked the two for a DBGH. I based my design on 300ohms, but I have spaced my elements to 4.25" (108mm). My phase lines are spaced at 2.125". In Single Bay form, this spacing of the elements seemed to work rather well. I just haven't installed reflector rods on it yet...but I decided to try it out as is.

My DBGH attempt

Close-up of the phase lines

This thing was big!

I was expecting to see, in the very minimum, the same results as the SBGH and M4...maybe picking up a weaker channel or two (ABC more consistently and a watchable lock with CBS) but nada. In fact it has performed worse. Example: I used the M4 and watched SunTV while I built this, and the Signal Monitor on the computer was reading around 25db (out of 30), and the bar was in the green. When I connected this antenna, the signal dropped to half, and the bar was yellow. It was still watchable, but the signal was far weaker.

I'm still in a testing phase, so the setups were virtually the same. I'm just running each antenna in the livingroom, pointed out the windows, seeing what I can pickup. The only difference is I moved the DBGH back from the window, so I could try and expose both sets of elements as much as possible. It's hard to raise it up as the size of this thing, I will hit the ceiling.

I guess the big question I'm asking myself is if the reflectors (either grid or rods) play an even more important role with the DBGH than a SBGH or bowtie antenna? Or is there something that I have missed? The GH is built using 10AWG copper wire for all the elements and phase-lines, and 3/4" PVC electrical conduit for framing. The only other thing is the 300ohm/75ohm feed is attached to the phase-lines by wrapping the contacts around the lines and then taping the connection with electrical tape. This is temporary until I get a chance to solder it in place, but could that make a big impact too?

I intended to use a DBGH to get the harder fringe channels from my location (NBC, ABC, CBS and maybe even Fox from Buffalo), but right now it is hard to justify. So I think I may just tear this down, and get individual reflectors for each SBGH.

*13/11/09*

I've been busy experimenting with a reflector on the M4, that I've put this antenna aside. Tonight I cut a piece of 1"x2" mesh for a reflector for this antenna. So I replaced the M4 with this antenna, placing it in the livingroom like usual. I have to admit, this antenna now with this sort of reflector, is kicking it. Not only are NBC, CBS, and ABC coming in stronger than what the M4 typically was able to do, the GH actually locked on MyTV and this station was very watchable, which the M4 was never capable of doing in the livingroom position. It only picked it up when placed high on the second floor. The GH also picked up PBS clearly, which was hit and miss with the M4 in the livingroom. Funny, even according to TVFool, FOX is closer, I couldn't get a lock on it, but MyTV was no problems. Also to note, I haven't even cut the 1" gap in the reflector yet as per 300ohms (digitalhome forum guru) suggests. Now, once the gap is cut, and I can get this on the second floor, pointing towards the CNTower...will this hopefully be what is needed to get these elusive Canadian channels? Right now, I'm really impressed with its performance, as it has now blown the M4 out of the water...no offense to the M4, as it is a great antenna to. My thinking may change though, that I was going to use this antenna to get Buffalo stations and the M4 for Toronto stations...I'm re-thinking this, and depending on what TO stations I can get with this antenna, I will be using this to get TO and the M4 to get Buffalo. Who knows...I have the second Hoverman still, and I may even sub out the M4 entirely and use that antenna as a demonstrator.

New Hoverman with reflector (only the 1" gap hasn't been cut yet)

I also took some screen captures of some of the signal measurements of various channels using this antenna:

ABC Buffalo

CBS Buffalo

NBC Buffalo

PBS Buffalo

MyTVNetwork Buffalo

CBC Toronto

*29/11/09*

Finally got up in the attic and was able to test the Gray-Hoverman there, and it did not disappoint. Placing it in two positions, I was able to get the full list of channels from Buffalo and a few from Toronto. All but one of the Buffalo stations came in at an average of 20db. ABC was really high for the US stations coming in at around 25db. The worst was MyTV which was still slightly hit and miss. Getting the antenna a little higher should help out, as it was just sitting on top of the insulation, leaning between the trusses for support. An addition of a pre-amp will also help in getting MyTV more reliably. I could also see possible problems with Fox and for some reason CBS, depending on the weather conditions. The Toronto stations still were elusive, where I was able to get CBC (both English and French), Omni 2, and I was able to finally pickup CTV. Global, Omni1 and CityTV are stations that are still giving me problems. Global and Omni most likely because their frequencies fall outside the capabilities of this version of GH antenna. CityTV's signal being too weak, and broadcasting in the opposite direction, to be picked up reliably in an attic install. Maybe a pre-amp would help here as well, I think. Some more height (aka an outside tower) would also help in order to get it, to me though, one channel is not a valid reason for putting up a tower. I'm not disappointed in the least, with getting 22 digital channels (this is including all the subchannels), and 13 analog stations. I can only hope that the post-transition period for the Canadian channels will play in my favour for receiving those channels which are eluding me still.

Now I just have to figure out how to permanently install the antenna in location. Most likely pointed towards Buffalo, then install the second one towards TO when its complete. The second one may be based on Jed's wide-range GH design found here: http://www.jedsoft.org/fun/antennas/dtv/gh.html (scroll to bottom of page). This would also help in getting those channels in the upper frequencies.

On a side note, the other nice thing was to be able to try out the LAN cable that I ran into the attic when I ran speaker wire up there a couple of years back. Worked a charm, as I had the HTPC connected to the antenna, then using a laptop in the attic, I VNCed to the HTPC so I could make antenna adjustments and get results without bothering anyone, or climbing in and out of the attic.

*30/11/09*

The one thing I noticed was that on the 28th, when first installing the antenna in the attic, my signals were all really good. It was a clear night, and I was running the antenna with about 20' of RG6. On Sunday, I ran an additional 20' for RG59, and the weather was overcast and raining. Fox and MyTV did not lock, and even NBC was problematic. I was a little nervous of this, so on Monday, the weather conditions faired better, so I took the same length of cabling (20' of each RG6 and RG59) and tested again. All the stations came in fine except Fox would freeze alot....even though the signal meter was reading back 17 to 20db. MyTV was good and strong, so I can conclude that the cable length played very little in any reception problems so far. Below are some channel screen captures:

ABC

CBS

CHCH

CW23

Fox (signal was there, but consistent locking/freezing)

MyTV

NBC

PBS

SunTV (from Hamilton)

Here are some pics of the install. I will optimize it when I finally install the second antenna.

8" length of PVC capped and screwed (both ends) to hold the antenna in place

*20/12/09*

The second Hoverman build, that will be going into the attic and pointing towards Toronto. With it I'm hoping to pickup CBC (English and French), CTV, and OMNI2. It would be nice to pick up some of the others, but I doubt that I will be able to do that, but I have my fingers crossed. I built this and spaced the elements similar to the Wide-band GH build that can be found on the jedsoft website, but it remains to be seen if it will actually pick up those upper limit channels. So far from testing, it has performed on par with the first Hoverman.

*26/12/09*

Installed the second GH up in the attic along with the first. CTV and CBC French were a little picky at under 20db, and when adding the splitter, the signal fell below the threshold, and I lost the picture. Fox and MyTV from the other antenna were also troublesome, but they were troublesome prior to the second antenna install, which they've always been a bit of a problem depending on the weather. Once I run the final cabling, I will put the split in the screens and do some final aligning. Here are some pics of the second install, and the two together.

TO antenna on the left, Buffalo antenna on the right, taken from attic opening

Toronto facing antenna

a second view. The bottom of the picture is the new laptop, which I used to VNC into my HTPC to help align the antenna.

The top of the Toronto antenna install

antenna on left is the Toronto, the Buffalo facing antenna on the right

same orientation as above

yet a third attempt

Buffalo facing antenna in the foreground

Basically right now from the CM-7777 power supply feed directly to the HTPC. Eventually as I add more ATSC capabilities at different locations, I will either use a CM3414 or 3410 distribution amp. The 3414 would be used outside of the Microyal switch as it has an 8dB boost which is more than sufficient in overcoming any loses in the diplexers, which I've seen about a 2dB lose, even though there really shouldn't be any lose. This is the more expensive way because of purchasing 8 diplexers, and the CM3414 is about $10 more than the CM3410. The advantage of the CM3410 other than the cost value ($10 cheaper, only 4 diplexers needed), is the fact that since it is a 15dB amplifier, it compensates the loss of the Microyal switch, which according to the datasheets, has upto 14dB insertion loss.

The Scatter Forager "grid" antenna in the image above will be used for picking up VHF-Hi channel 9, 11, 13, and VHF-Lo 6, post Canadian Transition, August 2011. Also I hope to pickup VHF-Hi 7 (WNGS) out of Buffalo, when/if they increase their ERP levels. Details of the antenna can be found here.

*7/3/10

Had some great tropo effects this weekend. I was able to pickup CityTV in HD (53.1) and amazingly for a short time, I picked up WXXI (16.1) out of Rochester @ 189kms away. Pretty amazing that I was even able to pick that channel up at all. Others have reported in picking that channel up as well. Below is some screen captures:

City HD

WXXI (unfortunately I didn't get a good screen capture of this, but it was gone before I could get a better one):

Used WatchHDTV to get this one.

*8/3/10

More great tropo effects allowed me to get ION for a brief while this morning...so I got some screen captures to remember this moment in case it never happens again (I'm positive it will though...I just want to prove that even an attic install can be pretty good, heh).

*4/7/10

Some unbelievable tropo tonight allowed me to net my largest find to date. WWTI from Watertown, NY. It broadcasts on RF21 with a PSIP of channel 50. There appears to be one subchannel with this station. It came in the early morning hours and was watchable for quite a while. Watertown looks to be around 300km from Hamilton. Not bad at all for an attic antenna, I must humbly admit.

*4/7/10*

Up in the wee hours (around 4am) paid off, as I finally picked up a channel out of Erie. I've had some signal response on RF50 in the past, especially in the last month with extreme tropo effects. Last night though, I was actually able to lock onto RF50 WQLN, which is a PBS station in Erie. The stream contained alot of errors, but I was able to score a few captures before it left. This PBS has two subchannels off its primary HD. Below are the screen shots:

*27/09/10*

Well, I noticed that over the course of the summer, I had lost the ability to pickup CTV out of Toronto. Also I noticed that OMNI2 and CBC French were both up and down (OMNI2 had always been very stable). I just figured that the warm summer air and with all the unbelievably strong Tropo affects, I just has some co-channel interference. Well I went up into the attic this weekend to install another antenna, and discovered that the Toronto facing Hoverman had a bend in it so severe that part of the elements were facing towards the attic insulation. You can see in the photos above, that the TO antenna only has the one vertical up the center which the reflector is tie-wrapped to. The reflector was coiled before installing on the antenna, so the reflector naturally wanted to coil back up, along with the heat and single support, resulted in the antennas weird contortion. I luckily had the frame work for a 2-bay bowtie already up in the attic which I didn't use, which had just the right length of vertical PVC. So I installed these verticals on this Hoverman and straightened the whole antenna. As soon as I did that, I now get a some-what good CTV signal again, and OMNI2 is rocksolid. Hard lessons learned about the harsh attic conditions.

Disclaimer:

I am not an electrical/electronics engineer, nor am I claiming to be a professional at designing electronic circuits, I am, though, an Electronics Technologist, and have a firm understanding of all the circuits that I have built. If you choose to try some of the projects that I have done, I take no responsibility to your lose of personal health or property. All projects are performed at your own risk.