91XG Attic or Roof Mount for 92397
 

I seem to be one of the lucky few in Wrightwood, CA 92397 who have a favorable TV Fool report, here it is:

http://www.tvfool.com/?option=com_wr...134977ba17f9d9

I'm only interested in getting that handful of LOS stations. I have a Antennas Direct 91XG coming in the mail tomorrow. Should I even try attic mounting, or will it have to go on the roof?

Also, the stations are broadcasting from 4500' elevation, while I am at 5800'. Do I need to tilt the 91XG down slightly?

If your house has a wood structure and a standard shingle roof the attic will work, however outside roof installation is always better. The vertical pattern on your antenna will allow for 0 degrees beam tilt. If you want to be "dead on" you could go 3 to 5 degrees negative.

Let us know how it works out.

At last report, the Victorville translators were all still analog except for WCET's K47CC. The only other digital station that serves Victorville/Barstow is KHIZ.

If you can make a list of the current fare that is received and the channel information (real channel, original channel, etc), it would be great.

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For reception of more Tv stations and channels install a Winegard HD7084P All channel antenna with a Winegard AP8700 preamp above the roof aimed at about 230 degree magnetic compass.

Here is how to aim antennas , http://www.kyes.com/antenna/pointing/pointing.html.

This is a Separate antenna and antenna system from the 91XG that is aimed north/east at bout 34 degree magnetic compass.

The 2 antenna systems Will Not be connected togeather on to one coax.

The 2 Separate antenna systems coaxes will go to the location of the Tv and will be connected to a remote control A/B antenna switch. http://www.radioshack.com , # 15-1968 or http://www.mcmelectronics.com , # 32-4425.

That's an interesting idea. I can live without the UHF channels at 230 degrees, so what about just a high band VHF antenna pointed in that direction to pick up the four channels in that range? Any antenna recommendations for that? Could I then use a VHF/UHF combiner, run one coax, and get by without the preamp and A/B switch?

By the way, I'll only be using two TVs on this setup. Actually, this is a vacation home, so we could even get by with only one TV.

The numbers on your TV Fool report suggest you have hope of receiving some of the VHF channels from Mt. Wilson. The only way to know for sure is to try. An Antennacraft Y10713 would be my choice.

Yes, a UVSJ would allow you to combine the signals from the UHF antenna into a common down-lead.

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The Y10713 is a antenna that is desinged to receive VHF high band channels 7 thru 13. Not VHF low band channels 2 thru 6 or UHF band channels 14 thru 51.

The Mount Wilson area Tv transmitters at about 230 degree magnetic compass that are receivable at -> Your <- location are in a process of changing the channels that are being transmitted.

The end result will most likely be that there will be VHF low band channels 2 thru 6 , VHF high band channels 7 thru 13 , UHF band channels 14 thru 51.

The way to cover what ever channel is changed to and not changed to is to install a HD7084P antenna that receives All the channels , VHF low band channels 2 thru 6 , VHF high band 7 thru 13 , UHF band channels.

Darn, I already put in an order for the Y10713. But the price was right, so I'll plan to install it, and if channel assignments change, I'll worry about that later. I plan to have a tripod mount on the roof which I can fold over for easier access to the antennas on the mast.

Thanks for the all the info. I will report back with how everything works out.

Per your TVFR, none of the UHF signals from Mt. Wilson have any reasonable chance of reliable reception. Given your question, , and initial statement, , the High-VHF is a reasonable approach.

The HD7084 would work well as a 2 through 13 VHF and would very likely add the signal from K39GY, a TBN (Christian programing) low power station. The UHF capability of the 7084 would go to waste if you connect it to a UVSJ.

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The UHF reception part of the HD7084P antenna would not go to waste.

The stations KNBC UHF channel 36 NBC and KVEA UHF channel 39 TELE. , would most likely be received by the HD7084P antenna.

The UHF part of the HD7084P antenna would be there when a Tv station/s change to UHF from VHF.

I recommened a 2 separate antenna system to cover as many channels as possible.

Just wanted to jump back in for a moment and say thanks for all the suggestions. Pointing an antenna towards Mt. Wilson at 230 degrees was something I had simply ruled out, since all the local residents said it was essentially impossible. Although I recently got my ham radio license and learned how VHF and UHF waves propagate differently, it took the second antenna suggestion for the idea to go after the Mt. Wilson VHF stations to "sink in".

I should add that this is primarily a vacation home which is often used by friends and family. So for that reason I prefer the UVSJ option and not something "complex" (well, it's not really complex, but to my non-technical family it is) like an A/B switch.

I had forgotten to change the default antenna height of 10 feet to my planned height of 25 feet, here is the updated report.

http://www.tvfool.com/?option=com_wr...1349573d2440bd

To my surprise, the four high VHF stations in red showing a LOWER NM (db) with the increased antenna height.

Also of interest is the pending application for KNBC on Channel 36 on Table Mountain just a few miles away. If that comes to fruition, I'll have to change everything. I hope the other networks follow suit. :)

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Not a suprise for me.

The bending of the signals across the mountains.

The signals are still receivable at the little lower signal strength.

Change the antenna height up and down and see what happens to the signal strength.

There is also a phenomena known as - ground wave - the Tv signals are stronger at about 0 to 5 feet above ground.

Back to the HD7084P issue.

At locations where there is a high rate of channel realocations I recommend a All Channel antenna that way all the channels are coverd.

California is a state where a high rate of channel realocations are taking place , and many Tv stations are batteling/fighting over who get to use what channel. And where a Tv transmitter can be built.

Ah, yes, that Table Mountain site is at 7400' elevation and is line of sight to most of the high desert. Double the coverage area at a fraction of the power output.

Made it up to the mountain cabin tonight, and the antenna install will happen this weekend. Here's a photo of where I'll install (deleted), sorry for the horrible nighttime quality, but it should be good enough for my additional question.

The satellite dish is going to come down, and the tripod is going on the roof peak as close to the foreground as I can. That is the best spot to get around the pine trees and have LOS from the UHF antenna to the signals from the Victorville translator at about 45 degrees. (Can't tell from the photo, so you'll have to take my word on that.)

I took the photo at about 240 degrees from where the tripod would be. So the VHF antenna for Mount Wilson would be pointed towards me. As you can see, there's a big pine tree trunk to the right. Am I far enough away from it, or would I have to move the tripod further along the roof peak? (That would be to the left and backwards in the photo). Though the problem with doing that is it may then put a pine tree in between the UHF antenna and the Victorville translator.

Just wanted to relay some initial observations after getting the UHF antenna up. Although my location is "blue" in the TV Fool charts, in practice the challenge was finding a good spot which wasn't blocked by the tree trunks. Make that "the" good spot, there was only one.

Channel 47 (KCET) is digital, I get a "lock" on it, and it is crystal clear. The remaining channels are from the Victorville translator, with color and sound, but varying degrees of snow. Those include 21 (CBS), 25 (NBC), 27 (Fox), and 51 (MyTV).

Reception was about the same whether the antenna was mounted right on top of the tripod on the peak of my single story roof, up until a few feet above it. I'd lose everything raising the antenna higher than that. One of my own tree branches was in the way. That will be dealt with. ;D

Photos and a full report after I'm done with all the tweaks.

Just to be clear, you receive all of your OTA programming from translators. You are receiving KCET's digital feeds from digital translator K47CC-RF47 out of Victorville. Each of your other received signals are broadcast by translators. However, they are broadcasting analog signals. This is why the signals have snow.

I forgot to connect the Channel Master 7777 preamp! In addition to the above, I now get analog 34 (don't know which one this is in the TV Fool report) and digital KHIZ (virtual 64, actual 44).

By the way, my CM7777 has only one input. The photos of others I've seen have optional separate VHF and UHF inputs, do they still make those? I'd rather get one of those since I plan on installing a separate VHF antenna.

The two-input Channelmasters were discontinued over the winter. You'd have to luck upon a distributor or dealer with remaining stock to purchase one new.

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I recommend a UVSJ = UHF/VHF Separator/Joiner. Antennas Direct has a UVSJ in a weather protected housing.

And use the -> New <- Channel Master Preamp.

I might end up with a situation in which the VHF and UHF antennas are on separate masts, probably about ten feet apart. In that case, what is best for the preamp? Combine the antennas into a UVSJ before going to a single preamp? Or separate preamps with two coax lines into the house? If I go the latter route, can I use a UVSJ after the power inserters in order to avoid an A/B switch?

The economical approach would be, place the UVSJ on the UHF mast, leaving you with a very short run of coax from the UHF antenna to the UVSJ. Run coax from the VHF antenna to the UVSJ. Place the mast-head portion of the preamp system just below the UVSJ.

This approach favors the UHF signals which will suffer more attenuation per foot of coax than the VHF signals.

The premium solution would be to use two preamps, one for each antenna.

Here's my blog post (with photos) about pointing my UHF antenna towards the Victorville translator. I can sum up by saying pine trees and UHF don't mix!

http://www.bikingbrian.com/2012/06/1...on-part-1-uhf/

Part 2 will be after I add the VHF antenna in the mix.

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Tip the front of the antenna up so the antenna looks at the mountain ridge.

That way the length of the antenna is in line with signals that are bent a little as come across the ridge.

The translator is at 4500 feet, my cabin at 5800 feet, and the ridge in between at 5500 feet. Should I instead tilt the antenna down a bit?

Yes, but given the distance involved when pointing north-east (26 miles) I doubt you'll see much effect unless you have a ground reflection or diffraction close in.
I think @Electron was referring to a south-westerly aim, in an attempt to receive some UHF out of Mt. Wilson. Sadly the predicted UHF conditions coincide with your neighbors local knowledge of the area.

In either case, start by bore-sighting along the boom. If aiming down on to the mesa, point straight at the transmitter antenna. If aiming toward Mt. Wilson, point the antenna at the top of the obstructing ridge. Then fine tune from that starting point, making small adjustments. Every dB of margin gleaned is well worth the effort.

Great, thanks.

Regarding the UHF antenna aimed towards the translator, the LOS indication in TV Fool is a bit deceiving. I wouldn't consider it LOS, at least in layman's terms, because if I drew a straight line from the translator to my cabin, the hill would be in the way. The elevation profile shows the signals coming from 4500 feet, hitting the ridge at 5500 feet, then propagating straight across (no knife edge like with VHF), though I can receive them since I'm higher at 5800 feet.

The VHF antenna to be aimed toward Mt Wilson will be pointed at a ridge that's clearly visible from my roof (no photo yet).

I'd opine that expanded use of channels 2-6 is extremely unlikely.

Yes, the trees and buildings almost always require a correcting elevation at the receiving end. Like your pine trees, the Douglas Firs here in the NW can require a 100' correction to the terrain model.

I wonder how soon we can expect the publicly accessible terrain mapping databases to include vegetation and structure detail. (When I started my career at the phone company the internet, cell phones and PC did not exist.)

Thanks for the information guys!

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BikingBrian you are doing Most Excellent of reporting your reception situation.

Thank You.

And please provide more.

No problem. The VHF antenna will come in the mail this week, and hopefully I can make it up to the cabin this weekend to install. And I'm not done with the UHF antenna either. :D

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Like I said , I do more then my best to make sure that the question askers get the correct information.
I recommended the HD7084P to cover ALL the channels for reception to the south.

Here are some Tv stations to , the south , south/east.

http://en.wikipedia.org/wiki/K39GY.

http://en.wikipedia.org/wiki/KSFV-CA.

KRVD-LP 5 , http://transition.fcc.gov/fcc-bin/tv...0&facid=128327.
http://www.ventechgroup.com

Also, in the next installment, I'll remember to give all of you credit for your help! :D

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Credit for the help is nice , however I am more interested in getting the reception.

Holy crap! I was just putzing around with the new Winegard YA-1713 VHF antenna on my back deck, and got I a lock on Channel 7!!!! (That's the TV image, not a reflection of me, sorry!)

http://www.bikingbrian.com/blog/wp-c...630-101355.jpg

Obviously I should do better on the roof. But I may want to tilt it up towards the nearby mountain peak. This antenna doesn't have a rotating mount like the 91XG, so any suggestions for how to get vertical tilt with the YA-1713?

Once you have the general aim point established, you know the forward and rear face of the mast relative to the station of interest.

Cut two pieces of sheet metal... so that each will wrap about half way around the mast. Place one on the forward face of the mast, the other on the rear. Hold them in place temporarily with tape until the antenna clamp holds them. The shim on the forward face needs to be lower than the rear so that only the bottom of the clamp contacts the shim, the front upper clamp 'teeth' need to contact the mast directly, not the shim. At the rear, the shim needs to contact only the upper 'teeth' of the antenna clamp.

If needed, add more shim stock.

An aluminum soda or beer can can supply the shim stock. Your wife's best sewing scissors can cut the aluminum. Or maybe not:p

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You see you are receiving channel 7 with out even trying and the signal for KABC 7 is a weak minus -1.5 NM(dB).

This low signal strength weak reception discovery , then also spills over in to the idea of weak reception of , VHF low band channels 2 thru 6 , and UHF band channels 14 thru 51.

Yes weak signals can be received.

I did my best to get you to install a antenna that receive ALL the channels

As for aiming the antenna up a little , bend the mast a little.

On another note, I correctly had the VHF antenna connected to the VHF portion of the UVSJ and the "line" portion of the UVSJ connected to the input of the preamp. But then stupid me connected the coax from the power inserter into the UHF portion of the UVSJ rather than the output of the preamp. Any chance I could have damaged the UVSJ or the preamp?

You're probably OK. The UVSJ is the least likely to have a problem with that. Some UVSJs will not pass DC or 60 Hz AC. If that's the case here, no current was flowing from the power supply to cause any damage. If the UHF port on the UVSJ presents a DC/Low-Freq-AC short, the power supply may not like being connect to a short circuit termination. Some power supplies have a non-serviceable fuse inside. Do you have a Volt-Ohm meter to check the power supply for output voltage? If not, just hook it up correctly and see if signal passes through the amplifier.