On Saturday March 27, 2021, I decided to get my portable HDTV ready for a trip to NC to visit my son. While getting it ready, I familiarized myself, again, with how to go through the menu system so I could scan for TV stations. Then I scanned a few of my Ham (Amateur) Radio antennas.
The purpose of this article, as the title implies, is to show that any antenna may do what you need done for your TV reception. You won’t know until you try it.
I decided to see how it would work with four of the antennas I have around the house. Two of these are TV antennas and two are not. One is a ham radio antenna for frequencies well below the lowest TV channel frequencies, the other is a vertical ham antenna for some of the ham VHF and UHF frequencies.
The antennas tested were:
1. An 80/40 meter dipole (D) (horizontal) (3.5 – 4.0 and 7.0 – 7.3 MHz)
2. A 2m/70cm J-pole (140-150 and 440-460 MHz) (J) (Vertical)
3. A UHF Home brew Porcupine Garage antenna (G)
4. A TV VHF/UHF antenna in the attic (A)
Interest: For those of you interested, you can see the Ham Radio Band Plan at: Ham Radio Band Chart or at: ARRL Ham Radio Band Chart and the Icom US Bandplan Update 2020
The first I tested was the 80/40 meter dipole for amateur radio. Now looking at this, many would say that this antenna, made for 3.5 – 7.5 MHz, would never work for TV stations in my area Ch 7 through Ch 36 at frequencies 174 – 608 MHz, but any wire of any length will pick up radio (TV) frequencies. The size, and orientation, will help exclude some frequencies but all frequencies will be picked up to some extent.
The 40 – 80 meter dipole is a mostly-horizontal antenna, but it is not pointed at either Baltimore or Washington DC. It is sort of bent so that half of it is broadside to Washington and the other half is broadside, mostly at Baltimore.
The results of these tests, at least for the ham radio antennas, was very rewarding. The dipole was able to get two Washington DC stations I’ve had difficulty getting with any TV antenna I have. These were the lower VHF station for channels 7 and 9 which are still on those frequencies. The only antenna set that even gets one of these stations is the attic pair.
I have not measured the strength or judged the quality of these stations. This was simply a quick-and-dirty set of tests. I did try to watch the stations for more than a minute each and found only one was flaking out during the time I watched. This does not mean all the others would be of good quality during inclement weather or with trees fully leafed.
Until next time, I hope you have good OTA reception,
Phil Karras, KE3FL
All my blog articles are listed at: Karras’ Corner
or
Karras’ Corner Article Links
on my KE3FL web site.
If you have LOS, you are a happy camper for RF. Location, location, location!
How true! My example with this one is that my antennas in the attic and on the roof could not get the Wash DC public broadcasting station WETA we like. I remembered that I had a multi-bow tie antenna in the garage so I hooked it up to a TV and found that it could get this station. This antenna is about 20 feet to the East of my antenna in the attic and 60 ft from the one over the kitchen on the roof. It is also 15 – 25 feet lower than those antennas. As you said, location, location, location.
Even within the same location RF signals behave differently. There is always a sweet spot to look for. Been there!
How true! Thanks TV Engineer for the input. I had a similar experience with a ham 2-meter HT. I found that the final had blown so I was working with only the exciter, less that a mW of power output. When I attached my car antenna I was able to go from Frederick MD almost all the way to Mt Airy, but a soon as I came down a hill the repeater was gone. Just like going over the horizon.
For TV (or any other VHF/UHF) just because you are behind something, like that hill or trees, it doesn’t mean you won’t be able to get your TV station, once you are far enough away from the shadow that is.
In these cases diffraction takes over and a pattern of vertical high & low power sections is formed. So sometimes moving an antenna up or down a bit will bring in a station well or not at all.
Another example: In the above article I said that my 80/40 meter ham dipole got channels 7 and 9 from Wash DC, but, as soon as Spring was in full bloom, and the trees had leaves, that antenna was worthless, no more Chs 7 & 9 from DC. Unfortunately, I can’t move this antenna up & down enough to see if I can find a high signal height. I am also right behind these trees so I would really have to get over them, which is rather difficult since they are so tall. No joy in this case.