Need help with DIY Antenna Design
 

Hey Folks, I live in the mountains of southwest Virginia. I plan to build a DIY antenna and would like input on the best design and size for my situation. My house is about 1600 feet elevation with nearby mountains that are are 3000 to 4000 feet high. If I cannot get direct signals, I am hoping that maybe I can get reflected signals. Any advice and help is appreciated. Dave

Welcome back, Dave

I see you have a previous thread:
Can I get OTA TV at my location?
http://forum.tvfool.com/showthread.php?t=15198

This is the image report that you gave in your previous thread:

http://forum.tvfool.com/attachment.p...1&d=1506711616

Thanks for the signal report image for this new thread. I see that you have entered an antenna height of 500 feet. Do have a 500 ft tower at 1401?

http://forum.tvfool.com/attachment.p...1&d=1506712166

This is a report at 20 feet based on the 1401 location in your image:
http://www.tvfool.com/?option=com_wr...e6a49b16d0a52d

http://forum.tvfool.com/attachment.p...1&d=1506714936

WCYB has NBC, CW, and Decades
http://www.rabbitears.info/market.ph...&callsign=wcyb

WKIN is Me-TV, Grit, Bounce TV, and Heroes & Icons
http://www.rabbitears.info/market.ph...&callsign=wkin

WJHL is CBS and ABC and will be moving to channel 9
http://www.rabbitears.info/market.ph...&callsign=wjhl

WSBN has PBS Encore but will be going off the air because of repack
http://www.rabbitears.info/market.ph...&callsign=wsbn

your report at 50 feet
http://www.tvfool.com/?option=com_wr...e6a42d0ed01454

http://forum.tvfool.com/attachment.p...1&d=1506717177

It is the real channel number that determines what antenna is needed.

VHF-Low, real channels 2-6
VHF-High, real channels 7-13
UHF, real channels 14-51

The virtual channel number (like 5.1) is a holdover from the analog TV days to maintain the identity of the station, and is what the TV displays.

A DIY yagi antenna for channel 5 would have elements about 6 feet wide; for 7 and 11, about 30 inches.

A ready-made antenna for VHF-Low and VHF-High would look like this:
https://www.solidsignal.com/pview.asp?p=hd8200u

this is their house brand equivalent
https://www.solidsignal.com/pview.asp?p=HD8200XL

I believe channel 5 also broadcasts on a UHF channel. If I need 6 foot long elements and a 500 foot tower it sounds like its not going to be feasible.

WCYB also has a transmitter on channel 29, but it is too weak for you even with your antenna at 50 feet.

Rabbit, I really appreciate your help. Is my situation hopeless to get TV OTA? Can you give me a scenario where I might be able to get a few channels (i.e. Antenna size and design). Reinvesting some money from the cable company to a big antenna might be worth it?

No, I don't think it is hopeless, based on your signal reports.

VHF channels are used for hilly terrain areas because VHF signals can make it over hills better than UHF signals.

I will work on a scenario and try to think of some inexpensive tests for you to make.

You might be able to receive WCYB and WJHL directly or from a reflection off the hill just north of the highway with the big Solid Signal HD8200XL antenna and a preamp.

For something smaller, you might be able to receive WJHL directly or off a reflection with the MCM 30-2476 and a preamp. The MCM antenna is inexpensive, but is on backorder. Put your name on the backorder list.
http://www.mcmelectronics.com/produc...-2476-/30-2476

redirects to Newark which is now combined with MCM
http://www.newark.com/stellar-labs/3...14_US%2Fsearch

Manufacturer: STELLAR LABS
Manufacturer Part No: 30-2476
Newark Part No.: 71Y5462

This shows the hill just south of your location that blocks the WCYB 5 signal:

http://forum.tvfool.com/attachment.p...1&d=1506794352

The WCYB signal coverage is very spotty in rough terrain:

http://forum.tvfool.com/attachment.p...1&d=1506794352

http://forum.tvfool.com/attachment.p...1&d=1506794352

The hill also blocks WJHL:

http://forum.tvfool.com/attachment.p...1&d=1506796150

WJHL is weaker than WCYB:

http://forum.tvfool.com/attachment.p...1&d=1506796150

http://forum.tvfool.com/attachment.p...1&d=1506796150

This is a contour map of the WCYB signal path and two hills:

http://forum.tvfool.com/attachment.p...1&d=1506802080

WJHL signal path with hill coordinates:

http://forum.tvfool.com/attachment.p...1&d=1506803999

TVFool report if your antenna is on Hill A:

http://www.tvfool.com/?option=com_wr...e6a48f7776b0d9

http://forum.tvfool.com/attachment.p...1&d=1506819389

TVFool report if your antenna is on Hill B, which is closer to your house. The signals aren't as strong as on Hill A, but stronger than at your house:

http://www.tvfool.com/?option=com_wr...e6a4f2c4f2f960

http://forum.tvfool.com/attachment.p...1&d=1506819787

Oblique view looking North, showing your location and Hills A and B:

http://forum.tvfool.com/attachment.p...1&d=1506820181

http://forum.tvfool.com/attachment.p...1&d=1506820366

What if he got landowner permission to put an antenna up in a tree on "Hill B", which is about 700 feet away. If he used RG-11, the losses even at the high end of UHF (700 MHz) would be around 20 dB. A CM-7777 pre-amp has 30 dB of gain, so it seems like this could work? I found a 1000-foot role of RG-11 for only $100. If he put in on "Hill A", the run is closer to 1000 feet but since the signals are about 20 dB stronger there, Hill A might be the better option.

Or maybe even the unmarked hill, (I'll call it Hill C), located about 1000-feet west of Hill B?

Possible coax source:
https://www.cablewholesale.com/products/coaxial-cable/rg11-bulk-...

Either that or put up a dual antenna to capture and re-transmit the signal down to his location.

Does anybody on the forum have direct experience with this approach?

I've seen a post on it, someone did it for a location in WV i believe. I'll look around for it.

Pretty technical :)

I'm just an end user

http://www.set.org.br/ijbe/ed1/06_IE...%20Antenna.pdf

Doesn't need to be that technical. It's basically just 2 antennas, one aimed at the towers, the other aimed at your house. Connected to each other with a short coax cable.

I'd try the bow tie style antennas with reflectors to block reception from the back side.

That is if you have permission to put them up on one of the hills.

Sorry.

I not the OP :o

Just found the topic interesting.

See other post for my situation

http://forum.tvfool.com/showthread.php?t=15276


Wish this idea was used by my now shutdown home owner's cable system.
Maintenance cost of the ridge head end facility forced the shutdown.