CS4 and CS5....Need advice on where to point and how to install

johnny4lsu · 2-Mar-2012, 2:22 AM

I'm a complete noob so please bear with me. I purchased the CS4 and CS5 and was hoping to catch all of the major channels. CBS, ABC, NBC, FOX. Can you guys tell me if these antennas can pick all those up and if so, which direction should I point them. Any other accessories needed to pick them up? Thanks for any help you can give me.

http://www.tvfool.com/?option=com_wr...0b862fd3cd68e8

Thanks in Advance,

Johnny

johnny4lsu · 2-Mar-2012, 2:35 AM

http://www.tvfool.com/?option=com_wr...0b862fd3cd68e8

I'm a complete noob and need help from you guys on direction, height, and other information. I have a CS4 and CS5 and I would like to catch the major broadcast channels FOX, CBS, ABC, NBC. Is this possible with my location and with these antennas? Do I need additional accessories? Which direction should I point these? Can I install them on the same mast?

My address is: (if this helps any)
Redacted for protection of OP's privacy
Washington, LA

Thanks in advance,

Johnny

Dave Loudin · 2-Mar-2012, 3:30 PM

I think you can get by with just the C5! To help appreciate what follows, read this document from Antennas Direct's site. Also keep in mind that the desired noise margin once we're done is +15. All your desired available stations have signals that are much stronger than that, which makes this much easier.

You have fairly strong network affiliates across a wide range of azimuth. Your two available NBC stations define this range: roughly 110 degrees to 320 degrees. No antenna can be uniformly sensitive across that entire range. However, by looking carefully, we can match antenna performance to the requirements presented by your TVFool report.

For VHF, you have stations roughly 110 and 210 degrees, a 100 degree spread. The station at 212 degrees has a noise margin of 54, so you don't need any antenna gain to capture it. The weakest station at 100 degrees has a noise margin of 9.9, so you would need about 5 dB of antenna gain for reliable results. NOTE: this is a second ABC station. If you don't care about it, then the next strongest station at that azimuth has a noise margin of 24, which doesn't need any antenna gain to be captured.

Look at page 3 of the document I linked to and you will find plots of the gain patterns for the C5 at VHF frequencies. Note that the antenna will still have +5 dB gain 25 degrees away from the center azimuth. From where the main beam crosses +5, rotate through the main beam 100 degrees and you'll see that the C5 has about -10 dB gain. That is plenty for the very strong stations, so you can set the C5 at 136 degrees and get what you want. (KLFY CBS, WAFB CBS, and WBRZ, ABC) Note that with this aim, we're getting close to a null for KLFY. A bit of tweaking to get it and WBRZ at the same time may be needed.

For UHF, you have stations at roughly 110, 160, 210, and 320 degrees. The weakest of these (discounting the low-powers and the second PBS) is WGMB, the second FOX affiliate, which has a noise margin of 24. To match the C5's UHF response, go to the last page of the pdf, equate the 0 azimuth to 136, then compare the antenna gains at the needed azimuths to the noise margins provided. You will see that, despite antenna gains as low as -10 in the needed directions, this is more than enough to receive a reliable signal.

You used 15 feet as the antenna height. Since you already have line-of-sight (LOS) to the transmitters you want, going higher will not improve the situation. All you need to ensure is that the antenna is not blocked to the front or back by local obstructions, like your house

Good luck.

ADTech · 2-Mar-2012, 6:04 PM

I was going to suggest the same thing, but Dave answered first. Try the C5 by itself (do not use the U/V combiner when doing this!) and see how it does.

Here at our office in St Louis (an all-UHF city), we only have one antenna on the roof - a ClearStream 5.

johnny4lsu · 2-Mar-2012, 6:08 PM

Quote:

Originally Posted by Dave Loudin

I think you can get by with just the C5! To help appreciate what follows, read this document from Antennas Direct's site. Also keep in mind that the desired noise margin once we're done is +15. All your desired available stations have signals that are much stronger than that, which makes this much easier.

You have fairly strong network affiliates across a wide range of azimuth. Your two available NBC stations define this range: roughly 110 degrees to 320 degrees. No antenna can be uniformly sensitive across that entire range. However, by looking carefully, we can match antenna performance to the requirements presented by your TVFool report.

For VHF, you have stations roughly 110 and 210 degrees, a 100 degree spread. The station at 212 degrees has a noise margin of 54, so you don't need any antenna gain to capture it. The weakest station at 100 degrees has a noise margin of 9.9, so you would need about 5 dB of antenna gain for reliable results. NOTE: this is a second ABC station. If you don't care about it, then the next strongest station at that azimuth has a noise margin of 24, which doesn't need any antenna gain to be captured.

Look at page 3 of the document I linked to and you will find plots of the gain patterns for the C5 at VHF frequencies. Note that the antenna will still have +5 dB gain 25 degrees away from the center azimuth. From where the main beam crosses +5, rotate through the main beam 100 degrees and you'll see that the C5 has about -10 dB gain. That is plenty for the very strong stations, so you can set the C5 at 136 degrees and get what you want. (KLFY CBS, WAFB CBS, and WBRZ, ABC) Note that with this aim, we're getting close to a null for KLFY. A bit of tweaking to get it and WBRZ at the same time may be needed.

For UHF, you have stations at roughly 110, 160, 210, and 320 degrees. The weakest of these (discounting the low-powers and the second PBS) is WGMB, the second FOX affiliate, which has a noise margin of 24. To match the C5's UHF response, go to the last page of the pdf, equate the 0 azimuth to 136, then compare the antenna gains at the needed azimuths to the noise margins provided. You will see that, despite antenna gains as low as -10 in the needed directions, this is more than enough to receive a reliable signal.

You used 15 feet as the antenna height. Since you already have line-of-sight (LOS) to the transmitters you want, going higher will not improve the situation. All you need to ensure is that the antenna is not blocked to the front or back by local obstructions, like your house

Good luck.

Thanks for the time, wisdom, and effort in putting this together. I'll do my best and let you guys know how it turns out. Thanks again!!

johnny4lsu · 3-Mar-2012, 9:54 PM

Thanks for the help! I picked up 18 channels including all the ones I wanted. The antenna is 3' off the ground at the moment and I still get all that. One question, when I install it up on my roof do I need to ground it? If so, how do you exactly do that. Thanks!

MisterMe · 4-Mar-2012, 2:37 AM

Your antenna's coaxial cable downlead should pass through a lightening arrester which is grounded. You should also ground your mast.

GroundUrMast · 4-Mar-2012, 4:44 AM

http://forum.tvfool.com/showthread.php?t=901

Ideally, an outdoor mast would be connected to the electrical service ground using a #10 gauge copper wire (or larger)... the most effective ground connection is short and direct, if bends are needed, they are not sharp.

Ideally, the coax down-lead would be run close to the electrical service ground. There, a ground-block would be connected to the service ground using a #10 gauge copper wire (or larger).