To Combine or Not to Combine

[cc362]

First of all, what a great forum.

Here is my signal analysis:
http://www.tvfool.com/?option=com_wr...46aec738f7f936

I have a DB8 antenna pointed NE and I get all but Fox with very strong signals.
I have a powered 4way splitter that goes to four sets and the signals still almost max out....well, except for KOLR, which is VHF. But, even that channel is always in the high 80s, 90s. Even today, during a heavy rain with lightning, I had no dropouts.

The problem is, I cannot get Fox. No bars at all.
The engineer at the Fox station told me to get an SR15 antenna (directional) and point it SE, at channel 31. (31.2 now also carries Fox).

I'm hooked to a Tivo and really don't want to have to use a rotor or A/B switch. I record several channels at night, at the same time.

Since my DB8 doesn't pick up the Fox channel at all and the SR15 will be pointed directly at Fox, about 80 degrees separation, would it be that difficult to combine them? If neither antenna picks up the stations of the other?

I'm looking for suggestions while waiting for the SR15 to arrive in about a week.

When I get it, I'll do some experimenting with what I have. But, if anyone has suggestions, I'd appreciate any help.

[ADTech]

It's odd that Fox isn't coming in. Simply moving the antenna several feet will likely fix it. It's probably just in a localized dead spot for that station, usually caused by blocked signal paths or reflected signals from hills trees buildings, or other structures. UHF dead spots can be as small as a foot or two and sometimes the antenna ends up plunked right into that spot by coincidence when installed. Since your plot indicates 1 and 2 edge path, raising or lowering the antenna will likely fix it.

Give the SR15 a try. Antennas that are at right angles to each other usually combine okay. Use a standard two-port splitter as the combiner.

[cc362]

Originally Posted by ADTech

It's odd that Fox isn't coming in. Simply moving the antenna several feet will likely fix it. It's probably just in a localized dead spot for that station, usually caused by blocked signal paths or reflected signals from hills trees buildings, or other structures. UHF dead spots can be as small as a foot or two and sometimes the antenna ends up plunked right into that spot by coincidence when installed. Since your plot indicates 1 and 2 edge path, raising or lowering the antenna will likely fix it.

Give the SR15 a try. Antennas that are at right angles to each other usually combine okay. Use a standard two-port splitter as the combiner.

Oh, the trials and errors of people in this area trying to get Fox.

A couple of years ago, Fox changed channels. The owners of the new channel didn't have a good transmitter and still don't.

Even on satellite and cable, the signal for Fox gets pixelated now and then. About the same time every night. I'm sure it is because they don't pick up a strong signal to pass along to subscribers.

Springfield Fox is using several small antennas tied together and I've read that people have to point their antennas directly at one of them to get any kind of signal. I've also read that people that live closer to Springfield get a stronger signal from Branson. I'm sure that's why the Fox Tech instructed me to point the SR15 toward Branson.

Antenna web doesn't even show the Springfield Fox available where I live.

There's a Joplin/Springfield forum where everyone complains. I would have thought they'd have to provide a better OTA signal to stay in business.

But, I digress. I'm just wanting to combine two antennas.

Thanks for the response.

Tivo's have Known issues with Digital Broadcast Tv Signals that not perfect.

--> ALL Digital Broadcast Tv Transmission and Reception is Less Then Perfect<--.

Tivo's tuners do not deal well with multi-path reception.

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Most Digital Tv's have tuners that do a good job with multi-path reception.

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Also Digital Broadcast Tv tuners can develop - Digital Glitches - that are not cleared out with simple channel scans.

Do Double Rescan.

http://www.wchstv.com/DoubleReScanAlert.pdf.

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If combining the 2 UHF antennas use a Isolation transformer type combiner.

http://www.winegarddirect.com.

Model CC7870.

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http://www.solidsignal.com.

http://www.amazon.com.

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[cc362]

I also have a US Digital HD Receiver that gets almost the same reception.
So, I'm pretty sure it's not a problem with the sets. It's the signal from Fox.

The main thing I watch is a projector. No tuner. So going directly to a set really isn't an option.

I'll read up on the "Isolation transformer type combiner".

Thanks for the comments and help.

I'm hoping these two things make it possible and easy:
1. 45 degree angle as opposed to 180.
2. Neither antenna will pick up the same channels as the other.

[ADTech]

Ah, Springfield, MO. I'm very familiar with the area and its requirements, but I didn't catch that earlier.

Yes, they have a very unique transmitter arrangement. I sat in on a meeting with their Chief Engineer and my boss a while back to discuss what could be done with their DTS.

You appear to be in a valley near Ozark. You have two opportunities for KBRK. They have a tower at Sunshine and 65 but I suspect it is uphill from your location. The other is KWBM in the direction of Bull Shoals.

The CC7780 is a thirty year old design that's basically nothing more than a two-way splitter. Don't waste time on it. You can pick up simple two-way splitter from Lowes or HD made by Ideal that will run circles around the CC7780.

As a preliminary test, can you aim the DB8 directly at either candidate transmitter and pick up its signal? That will tell lot about whether the SR15 project is going to be useful.

[cc362]

Originally Posted by ADTech

Ah, Springfield, MO. I'm very familiar with the area and its requirements, but I didn't catch that earlier.

Yes, they have a very unique transmitter arrangement. I sat in on a meeting with their Chief Engineer and my boss a while back to discuss what could be done with their DTS.

You appear to be in a valley near Ozark. You have two opportunities for KBRK. They have a tower at Sunshine and 65 but I suspect it is uphill from your location. The other is KWBM in the direction of Bull Shoals.

The CC7780 is a thirty year old design that's basically nothing more than a two-way splitter. Don't waste time on it. You can pick up simple two-way splitter from Lowes or HD made by Ideal that will run circles around the CC7780.

As a preliminary test, can you aim the DB8 directly at either candidate transmitter and pick up its signal? That will tell lot about whether the SR15 project is going to be useful.

I have a 2 way splitter left over from some past configuration that I'll try first. Printed on it is "2-WAY SPLITTER, 2-2150 MHz" . On the input it has "DC power pass".

I am up a bit, on the side of the hill, and not all the way down in the valley, so I'm hoping that will help.

At this time, I don't want to go up on the roof. I'm waiting on the new antenna first.

About a year and a half ago, while cleaning rain gutters, my ladder slid out from under me. I broke both ankles and have some hardware in my left one as a reminder. So, I'm a little leery about going up there. I'm hoping to do all my testing, trouble shooting and install in one trip.....if I can get my wife to do the scanning down below.

Again, thanks for your help.

[cc362]

Okay, I can pick up the Fox channel to the south with the SR15.

But, seems I have a problem. I can't get the signal from the SR15 antenna to go through the splitter I'm using to join the antennas. Works fine hooked directly to the box.

The DB8 works fine hooked directly to the box or singularly to the splitter.

The signal from the DB8 goes through the splitter fine, with or without the SR15 hooked in.

I thought it might be a problem with combining the two antennas, but the signal from the SR15 won't go through even when I disconnect the DB8.

Right now, the SR15 just lying on the deck and getting fair reception of most channels. The exception being CBS with is VHF.

I'm wondering if I jumped the gun buying the SR15.

Isn't the DB8 a stronger antenna?

I'm thinking I should have just gone up and turned it south instead of listening to the tech from the local Fox station that advised me to buy the SR15.

[ADTech]

Probably not enough signal power left. You might need to amplify the SR15's signal then hope the combining experiment works.

[cc362]

I'm using a 4 way amplified splitter also to go to 3 TVs, soon 4. I've tried different variations with it and still can't get the signal through the other splitter (joiner).

Is there much of an amplification difference between a 4 way amplified splitter and just an amplifier?

[ADTech]

If you cannot get a signal from the SR15 through the splitter and the splitter is not defective or inappropriate, that means you need to amplify its signal BEFORE the splitter.

Can you identify what you're trying to use to combine the signals?

[cc362]

Okay, I bit the bullet and climbed onto the roof.

I turned the DB8 to the south and now it picks up all the networks.

It's ran directly to the Tivo for one TV.

I'll use the sr15 and splitter for the other TVs.

The splitter is "4 Port Cable TV/HDTV/Digital Amplifier Internet Modem Signal Booster Internet AMP".

I bought it here:

http://www.amazon.com/gp/product/B001EKCGT8/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

The splitter I was using to try to join the signals says "2-WAY SPLITTER, 2-2150 MHz" . On the input it has "DC power pass". To me, it looks like a normal 2 way splitter.

But, here's how my luck goes.

Both the Springfield and Branson Fox channels show up as 49.1 on the program list.

I don't receive KRBKDT out of Springfield, but Tivo lists it and channel guide info does show up.

I get KRBK out of Branson (actually on frequency 31), but Tivo doesn't carry the guide for it, so it shows "To Be Announced".

I called Tivo and they're suppose to get it added.