Antenna advice for Low VHF channel
This is a discussion on Antenna advice for Low VHF channel within the DTV | HDTV Reception and Antenna Discussion forums, part of the Over-the-Air (Antenna TV) category.
DTVUSA Jr. Member
I am seeking some advice on an antenna to help me get KHAS channel 5 which is one of the few stations that broadcast in low vhf. I currently have a damage Chinese rotating antenna on my roof which I am ready to replace. Actually I am only using rabbit ears right now and am getting all the channels in the area except KHAS on 5 so am I right in thinking all I need is a good low vhf antenna?
Also, does the coax cabling type matter, such as using RG6 Quad vs RG6 or solid copper vs copper coated steel?
Please let me know what you think or if you need more information.
SEE LINK BELOW FOR MY TVFOOL INFORMATION
Welcome to DTVUSA. I grew up in Arthur County Nebraska, my mother was from Sumner, and she graduated from Kearny State College (A.K.A. UNK, Go Antelopes). Also, my cousin was the American Baptist pastor in Kearny back in the 1980's. Anyway, since your in the green and white on TVfool, I'll recommend one of these two antennas pointed toward 95 degrees from magnetic north.
Winegard HD7000R VHF/UHF/FM DTV TV Antenna (HD-7000R) - Winegard - HD-7000R - Antennas&sku=
AntennaCraft AC9 Low Profile VHF UHF FM HD Antenna (AC9) - AntennaCraft - AC9 - 716079000765 Antennas&sku=716079000765
If you get a VHF/UHF combo, you will have all your signals on the same line. Any quality RG6 cable should work great. Tape the joints to keep moisture out and be sure to ground the mast and the cable (ground the cable using a grounding block just before the cable enters the house).
To begin, low-band VHF television is very prone to receive interference from man-made noises such as fluorescent light ballasts, electric motors like your kitchen blender or a neighbor's air conditioner, etc., so I propose a very inexpensive test to see if you have enough signal versus noise to allow reception of channel 5. If you find 'noise interference' you may be able to track the sources down and eliminate them, before you continue with permanent antenna plans.
I am an experimenter and I'm shooting from the hip on this one, but why not! Any "conventual" low-band television antenna is going to be VERY large but since your station is LOS, I have a wild idea.
The transmitter is located at 100 degrees almost due east to you. Does your home have an outdoor wall that 'broadsides' that direction? I'm thinking about building a simple half-wave folded-dipole wire antenna, cut to that channel. Half of the people on the Forum will think I'm nuts to suggest this, but the Ham Radio operators here will understand the simplicity of the test I propose.
All outside TV antennas that were designed (compromised) to work on low band-high band VHF are now considered to be obsolete, as there are very few low band VHF stations remaining. This is not to say a VHF-high band/UHF combo antenna might be the answer for you, but I suggest you try a simple test and if it works, you could use a far smaller antenna for the rest of your channels and combine my 'plan' with a smaller UHF antenna. Here we go:
This link---> http://frwebgate.access.gpo.gov/cgi-...2002&TYPE=TEXT shows channel 5 spans 76-82 mHz, so your design frequency should be 79 mHz.
This link ---> http://www.angelfire.com/mb/amandx/dipole.html determines the length of a dipole antenna.
For 79 mHz, you would need a little over 12 feet of wire: I prefer stranded bare copper, but anything would work for a simple test (possibly all you need)! The actual lengths are 5.92 feet in overall length, 2.96 feet per half. Now you see, a dedicated channel 5 'conventual' rooftop antenna would have to be be a six-foot-wide monster.
The second link (above) pictures from left to right shows a ceramic or plastic insulator, a quarter-wavelength section of wire, a center insulator where the coaxial feedline is attached, a second length of wire cut to the same length as the first one, and a third insulator. This could be fabricated in a few minutes and it would cost virtually nothing to try. Test this horizontally.
Regarding coaxial cable, there are big differences between brands. A local Engineer tested several brands and he determined Radio Shack coax is leaky and lossy: next, be certain to use black-jacketed coax rather than white as it resists ultra-violet (sun) rays far better than other colors. Preferred are commercially installed coaxial fittings (factory cut 25/50/75/100 foot lengths) unless you have the proper tools to install fittings.
Regarding grounding your antenna mast, there are posts here on the Forum (search grounding) that illustrate why a simple 'Radio Shack' coaxial grounding block is not considered to be enough for safety and they do not meet National Code. Once you are satisfied with your antenna setup, be sure to waterproof all of the coaxial fittings using RTV or a similar product.
Last edited by Fringe Reception; 07-17-2010 at 08:28 PM.
My parents are stuck trying to pull in KNOP, North Platte (RF2) from 48 miles away. Fun, fun, :-)
And, I need to add, that in Nebraska low VHF is very much alive. RF 2,5,and 6. Since I live in Colorado, I don't have to deal with it for myself, but it is a very real issue in Nebraska.
Last edited by dkreichen1968; 07-17-2010 at 06:38 PM.
DTVUSA Jr. Member
My father grew up near Sumner too. I was born and raised in BBow and now live near Kearney. I really appreciate you and "Jim in Seattle" taking the time to help me out. After reading both posts I think I will try my luck with one of the antennas suggested instead of doing the wire test. I don't have any bare copper wire and would have to buy some. My thinking is I know I can get the UHF channels pretty easy with rabbit ears and I need a new antenna anyway. I have been without satellite or cable for around 10 years now and if I can't get KHAS, I will survive.
Originally Posted by dkreichen1968
I will follow up with my results hopefully within the week.
If you know who R.P. Smith is from Broken Bow, he is married to my cousin.
Originally Posted by morty
DTVUSA Jr. Member
I do know who he is. As a matter of fact, he is shirttail relation to my wife. 4th cousin or something like that. Her grandma and RP dad were 1st cousins. Sorry for the public genealogy lesson, but I can't PM yet.
So, we're related through the T.V. antenna. I remember my dad talking about being related to RP and Beth with one of RP's relatives, and something about one of RP's horse trades, and them deciding they were related through the horse. ;-)
DTVUSA Jr. Member
Antenna from Solid Signal should be here tomorrow. Went with the Winegard HD7000R
DTVUSA Jr. Member
She is installed and working great.. Pulling channel 5 as I had hoped! I truly appreciate the advice and am very pleased it was such a low cost solution for this nagging little problem.
Thanks for letting us know that it worked!!!