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Topic:
Gray Hoverman Antenna or Something Better for North San Diego HDTV
This thread has 5 replies. Displaying all posts.
Post 1 made on Friday September 13, 2013 at 15:33
SDShack
Lurking Member
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September 2013
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Hello, new member here. Have been investigating cutting cable the last few months and have been experimenting before I make the break. Manufacturing Engineer so I understand technical problems and am persistent enough to search for help and try things, but I don't consider myself a Technology Expert. That's why I am asking for help here.

My location is North San Diego County, which puts me about 30 miles North of a VHF tower for CBS & ABC, and 40 miles Northwest of UHF tower for Fox, PBS, Independents, and NBC. I have always had cable for the 12 years I have lived here, so I never knew how OTA signals were. My house is 2 story, but kind of in a little valley, with a good size hill/plateau along the entire South skyline. No one in my neighborhood as OTA TV antennas, so I decided to try a DIY Gapless Gray Hoverman design from John Davis, and modified it a little. My first attempt did not have a reflector, and it was wildly successful. I was able to pickup around 55 channels between SD and LA. The LA channels really surprised me because I am 80 miles from those towers, but most of the signals were spotty, and would cut out frequently.

My only failure was the inability to pick up KNSD (NBC) out of SD at about 40 miles. It operates at UHF 630 MHz, but only broadcasts at 18 kW ERP. The fact that I was able to get UHF stations above and below this frequency made me think that my antenna array is correct, but the signal is too weak.

So I tried a reflector and pointed the antenna to the South. That cut my channels down to about 22 (lost the LA channels). Still couldn't get NBC. Then I made sure my compass direction was good for my house, and that it was pointed at the NBC tower (153 degrees SSE). Still no NBC, but that alignment made me lose CBS & ABC (VHF channels 180 degrees S). So I added a folded dipole 18" above my Gray Hoverman, and aimed at 180 degrees and immediately added those stations, plus a couple of VHF from LA for a total of 25 stations now.

In summary, my current system is mounted on my roof, about 5' above my chimney. It's a modified gapless Gray Hoverman aimed at 153 degrees with a folded dipole on top aimed at 180 degrees. Each antenna has a 300 ohm cable, and both of these cables are attached to a single Balun, that connects to 40' coax (2-20' cables with a connector), that attaches directly to my HDTV - no cable box. My only problem that I need help with is I still can't get NBC out of SD, but can get the other UHF stations that broadcast from the same tower.

That leads me to 3 questions:
1. Is my inability to pick up NBC because the signal is too weak? If so, can that be solved with some type of signal amplifier, and if so, what is a good recommendation? Note- several weak stations from LA are strong enough for my TV to "tune them in" during setup, but too weak to broadcast a picture when I select the channel. With this NBC-SD problem, the TV has NEVER once tuned in this station, let alone broadcast a picture.

2. Is there a better commercial antenna out their that could solve my problem rather than going with the DIY route? If so, what are the recommendations?

3. This is a little off topic. Has anyone ever designed and used a bi-directional Gray Hoverman with a reflector? In my case, I am wondering if one array pointed NW 315 degrees (for LA), and one array pointed SSE 135 degrees) for SD with a reflector grid sandwiched between the 2 arrays would work to allow me to pull in stations from both LA and SD?

That's all for now. Sorry for the long post, but any help, comments, would be much appreciated as there seem to be a lot of very knowledgeable folks on this site.

Last edited by SDShack on September 13, 2013 15:46.
Post 2 made on Wednesday September 18, 2013 at 23:58
Ernie Gilman
Yes, That Ernie!
Joined:
Posts:
December 2001
30,104
I write long posts, too, so we can relax about that.

On September 13, 2013 at 15:33, SDShack said...
My location is North San Diego County, which puts me about 30 miles North of a VHF tower for CBS & ABC, and 40 miles Northwest of UHF tower for Fox, PBS, Independents, and NBC. I have always had cable for the 12 years I have lived here, so I never knew how OTA signals were.

This recommends that you get an antenna rotor if you cannot get good enough signal pointing in some one direction. I assume you have looked at tvfool.com or antennaweb.org to verify the directions to the transmitters. Just pretend you want to know what antenna to buy, put in your address, and let them work it out.

My house is 2 story, but kind of in a little valley, with a good size hill/plateau along the entire South skyline.

Could be a problem, might not be. It must be checked with a good antenna that you can point.

No one in my neighborhood has OTA TV antennas,

That just means they have cable or a dish.

so I decided to try a DIY Gapless Gray Hoverman design from John Davis, and modified it a little.

Excuse me, but I buy commercial antennas. I have had to supply antenna systems for retail stores, and the last three I did had more than four hundred TVs in each store. Plus 60 FM receivers.

My only failure was the inability to pick up KNSD (NBC) out of SD at about 40 miles. It operates at UHF 630 MHz, but only broadcasts at 18 kW ERP. The fact that I was able to get UHF stations above and below this frequency made me think that my antenna array is correct, but the signal is too weak.

Or the aiming is wrong. Or the antenna is too high or -- get this -- too low. It could be!

Then I made sure my compass direction was good for my house

The tvfool and antennaweb maps can be printed, and then you can stand on the roof and orient the antenna with relationship to the street!

etc etc So I added a folded dipole 18" above my Gray Hoverman, and aimed at 180 degrees and immediately added those stations, plus a couple of VHF from LA for a total of 25 stations now.

This is sounding pretty good overall.

In summary, my current system is mounted on my roof, about 5' above my chimney. It's a modified gapless Gray Hoverman aimed at 153 degrees with a folded dipole on top aimed at 180 degrees. Each antenna has a 300 ohm cable, and both of these cables are attached to a single Balun,

How? Are the cables paralleled? For best isolation they should each be converted to 75 ohm, then those outputs run backwards through a splitter to combine them. This might give you overall higher signal level.

that connects to 40' coax (2-20' cables with a connector), that attaches directly to my HDTV - no cable box. My only problem that I need help with is I still can't get NBC out of SD, but can get the other UHF stations that broadcast from the same tower.

Be sure when you write SD that nobody thinks you mean standard definition. I did for a moment there.

That leads me to 3 questions:
1. Is my inability to pick up NBC because the signal is too weak? If so, can that be solved with some type of signal amplifier, and if so, what is a good recommendation? Note- several weak stations from LA are strong enough for my TV to "tune them in" during setup,

What is "setup"?

but too weak to broadcast a picture when I select the channel. With this NBC-SD problem, the TV has NEVER once tuned in this station, let alone broadcast a picture.

Is it possible NBC in LA might do for you?

2. Is there a better commercial antenna out their that could solve my problem rather than going with the DIY route? If so, what are the recommendations?

My favorites are the Channel Master CM2016 or CM2020. The Winegard HD8200U has been THE CHOICE for getting stations 75 miles away for more than twenty years. However, you must compare the antenna's channel frequency capability with the channel frequencies you're looking for. That NBC in San Diego might be on too low of a channel for the antennas you're dealing with!
3. This is a little off topic. Has anyone ever designed and used a bi-directional Gray Hoverman with a reflector? In my case, I am wondering if one array pointed NW 315 degrees (for LA), and one array pointed SSE 135 degrees) for SD with a reflector grid sandwiched between the 2 arrays would work to allow me to pull in stations from both LA and SD?

I have no experience with this. Know, though, that if the signal comes in straight and directly on one antenna, and also comes in near that signal level with a lot of echoes due to the signal being reflected off of hills and what not, those signals will be combined, lowering your overall signal quality for that channel. And when you have two antennas, every signal will be brought in off both antennas; problems only occur when one signal is crappy and near the signal level of the other. You can determine this on a clear day by recording whatever info you can about what stations you get; first with one antenna, then with the second, then with the combination.

As a result of this stufy, you might decide you want to switch from one antenna to the other. Private Message me if you want info on going that route. I might be able to solve the problem but you'll want to spend the time ( = $ ) gathering the raw information yourself.

Though one great antenna with a rotor is still a good answer: there's never any cross-contamination of signals and you can adjust the pointing while you watch.

And did I tell you I do antenna systems? I could come up with a method of switching antennas for you and install the darn thing.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
OP | Post 3 made on Wednesday September 25, 2013 at 22:55
SDShack
Lurking Member
Joined:
Posts:
September 2013
3
Hi Ernie, thanks so much for responding to my post. My ONLY problem is I can't pick up KNSD NBC San Diego (UHF 630 MHz). This station only broadcasts at 18 kW ERP from a tower located at 153 degrees SSE at about 40 miles. My DIY gapless Gray-Hoverman DOES pick up the other UHF stations (Fox, PBS, Independents) from the same tower just fine. So I know my antenna is aimed properly, and actually works properly. The only problem is picking up NBC-San Diego.

The "set-up" I mentioned was my HDTV "auto set-up" feature. When I run this to set-up my over the air stations, I sometimes get some of the "spotty" stations that are on the fringe. This was mostly LA stations that are 82 miles away. In fact, I was able to get KNBC (LA) a couple of times. By "spotty" I mean that my HDTV tuner grabs the signal during set-up, but when I access the channel, often I get an error message saying "no signal", but other times I get a spotty signal, and even a few times I get a clear picture. My point is, no matter what I try, I have NEVER gotten even a "no signal", let alone spotty signal like this from KNSD NBC San Diego. It's very frustrating because I have gotten as many as 55 stations from both SD and LA using this DIY antenna so I really feel like it has something to do with a weak signal from KNSD NBC San Diego.

I'm not trying to be cheap here by going DIY. I am more than willing to buy a retail antenna and really appreciated the recommendations you provided. I will definitely check them out. The only reason I went DIY first was because I knew my distance to the towers was pretty far, plus my topography surrounding my house was a concern. For example, I had really poor cellphone reception at my house with Verizon. I had to hold my cellphone up in my 2nd story skylight to get good reception. So I didn't want to shell out a bunch of money for a retail antenna, plus going through all the hassel of installing it one my roof, just to find out that I wouldn't get good reception. So that's why I went DIY first, and am actually ecstatic with the results, except for the inability to pick up KNSD NBC San Diego.

My only other question that I didn't see a response from you earlier was concerning any type of amplifier. What's your thoughts on adding an amplifier/pre-amp? Would this offer any benefit? If so, do you have a recommendation?

I'm not worried about tackling the 2 different antenna scenario. I am confident I can solve that once I get the KNSD NBC San Diego issue solved.
Thanks again for your help!
Post 4 made on Monday September 30, 2013 at 00:58
Ernie Gilman
Yes, That Ernie!
Joined:
Posts:
December 2001
30,104
On September 25, 2013 at 22:55, SDShack said...
Hi Ernie, thanks so much for responding to my post. My ONLY problem is I can't pick up KNSD NBC San Diego (UHF 630 MHz). This station only broadcasts at 18 kW ERP from a tower located at 153 degrees SSE at about 40 miles. My DIY gapless Gray-Hoverman DOES pick up the other UHF stations (Fox, PBS, Independents) from the same tower just fine. So I know my antenna is aimed properly, and actually works properly. The only problem is picking up NBC-San Diego.

Please refer to channels by real channel number, not frequency, and/or by call signs for what you're trying to do as that's how the reference sites cite them.

Something is squirrely here.

I just went to tvfool.com and pretended I was in 91911. I have no idea where any zip codes are in your county, nor what zip code you're in. That's another bit of info needed to follow this through.

tvfool shows me the info from 91911. This is only a few of the stations shown there, but I'll concentrate on the stations in the same direction as KNSD. This edit window does not do TAB moves so I'll put periods between info...

call...........chan.....sig pwr....
KUSI-DT.....18.....-24.4...
KSWB-TV....19.....-24.5...
KPBS-DT.....30.....-25.4...
KNSD-TV.....40.....-26.0...

So this analytical tool says that KNSD is the eleventh strongest signal in 91911 and within two degrees of the others shown. I know you are in North County, but that alone does not explain why you cannot get KNSD when it is nearly equal in signal level to these other stations, which in my example are about 8 miles from the tower.

You have not supplied enough information for me to look at the tools I have and suggest an answer. Please run a tvfool report for yourself and see what it says. And share it.

By the way, there are other stations in that general direction, but their signal power levels are more than 10 dB down from these guys. I don't know what's happening there, by the way. Also I checked the LA stations that showed up in this report. There aren't any on Ch 40 and they're all about 60 dB lower anyway.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
OP | Post 5 made on Monday October 14, 2013 at 19:10
SDShack
Lurking Member
Joined:
Posts:
September 2013
3
Hello again Ernie. Thanks again for responding to me. Sorry it has taken so long for me to reply, but I have been busy with other things. Anyway, here are some more details that you asked for. Any advice you can offer would be appreciated.

I have looked at the TV Fool website before, and I have the TV Fool report and can share it, but I don't know how to post the attachment here. So I guess it would have to be emailed to you if you really want to see it. Anyway, I entered in my exact decimal coordinates for my location (33.21667/-117.25), and also my estimated antenna mast height of 30'. The result was somewhat different than just entering in my street address and zip code, so I assume the report using the exact decimal coordinates are more accurate, so that is what I have listed below.

call......real chan.....sig pwr...true azimuth

KVND-DT....23.....-48.1.......24
KFMB-TV.....8.......-51.1......180
KGTV-DT....10.....-53.0.......180
KHAX-LP.....49.....-58.7.......180
KSWB-TV....19.....-74.7.......153
KUSI-DT.....18.....-76.4........153
KPBS-DT.....30.....-78.5.......153
KNSD-TV.....40.....-79.1.......153
KTTV...........11.....-82.9.......326
XEWT..........12......-71.1......326
KCOP-TV......13......-83.9......326

My HDTV was able to grab all of the above stations, EXCEPT KNSD Channel 40 when I ran the auto setup function on my HDTV with my DIY antenna attached.
That is what is so frustrating, because KNSD broadcasts from the same tower location as KSWB, KUSI, KPBS, and I get all of them just fine.

FYI, I get KFMB and KGTV (these are VHF stations) using a separate dipole antenna mounted with my DIY Gray Hoverman, but the dipole antenna is pointed at the slightly different azimuth direction 180. All the other stations (except KNSD) come in with my DIY Gray Hoverman antenna all at the same time, when pointed at roughly azimuth 153.

So let me know if you have any other thoughts on this, and thanks again for trying to help me.
Post 6 made on Saturday January 18, 2014 at 18:20
BillFromGI
Long Time Member
Joined:
Posts:
March 2009
179
Hey SD, try using one piece of cable like RG-6 quad shield cable from the antenna to the TV instead of using two coax cables connected together with a barrel connector. Let us know what happens.. .


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