Does anybody want to buy an LPTV station?
For several months now, I have been taking care of an LPTV station in Syracuse and the owner is looking to sell. It is in a pretty good location; on a tall building downtown. It has a newer transmitter and antenna, EAS gear, located in a conditioned space, etc.
If you are interested, contact me for details: info (at) engineeringradio (dot) us
We recently put an LPTV on the air in Brookfield, Connecticut. WXGN-LD signed on on Friday, September 6th.
This is UHF station with a 15 KW ERP (the limit for LPTV). This station has an elliptically polarized antenna with 4.5 KW in the vertical polarization.
The transmitter is made by a Spanish company called TRedess
This has been installed in a former Sprint cell building. The wire ladders are left over from them. Still, it makes a convenient place for the mask filter, which is up and out of the way.
I also swept the antenna and filter.
This station is associated with these folks: XGN Network LLC
One of the many projects we are currently finishing up. Over-The-Air TV is making a comeback.
A few things about LPTV; These stations usually have an ERP of 15 KW or less, and they are a secondary service, like FM translators, which a full-power TV station can displace.
This is an ATT microwave site built in 1977 according to county records. This may have been one of those VHF Mobile Telephone sites which existed before cellular telephone systems. ATT owned it until 2022 when it was sold to a private business.
This station is on channel 31 or 575 MHz center frequency. UHF TV stations often use slot antennas, which have gobs of gain. Slot antennas are simple designs that have a broad bandwidth and until recently were mostly horizontally polarized. This particular antenna is elliptically polarized which is becoming more common as TV providers are looking at mobile video applications.
Slot antennas are the inverse of a dipole antenna. A dipole is two conductive poles approximately 1/2 wavelength surrounded by free space whereas a slot antenna is 1/2 wavelength of free space surrounded by a conductive plane. The width of the slot determines the bandwidth of the antenna. Radiation from a dipole is in the plane of the two poles versus the radiation from a slot that is perpendicular to the slot. At UHF frequencies, many slots are placed on the radiating plane, giving large gain figures.
All TV transmitters require a bandpass or mask filter. This is to keep out-of-band emissions out of the tightly packed TV spectrum.
These filters need to attenuate the upper and lower shoulders of the digital carrier by 46dB +/- 3.25 MHz from the center frequency.
These are fairly straightforward filters, this one has six cavities with plungers that slide in and out to adjust the tuning. I watched one of these get retuned in the field, it takes quite a bit of time and patience to complete and requires a two-port network analyzer.
With the TPO of 400 watts, the ERP is 4.7 KW horizontal and 2.35 KW vertical.
So, why bother with all of this? Indeed that is a good question. As cable companies continue to raise their rates (the average cable TV bill is $250 or so) people are looking for alternatives. Cord cutting is a thing and OTA (over-the-air) TV as well as OTT (over-the-top or direct streaming) are popular alternatives.
This station will run France 24 English service and NASA TV to start. Other things you can find on Low Power TV stations; Heartland (mostly country music with some cooking shows mixed in), Retro (old movies), Rewind TV (Old TV shows), Buzzr (old game shows), Court TV, Weather Nation, News Net, etc. More information on OTA TV networks can be found here: https://en.wikipedia.org/wiki/List_of_United_States_over-the-air_television_networks
Rabbit Ears has a good signal search page if you are interested in OTA TV: https://www.rabbitears.info/searchmap.php
More information on Low Power TV (or Local Power TV) and be found here: https://www.lptvba.org/
For a sometimes interesting discussion on cord cutting in general, try this: https://old.reddit.com/r/cordcutters/
Many people are surprised that OTA TV (Over The Air Television) is still a thing. I am here to say that there are lots of TV stations still broadcasting. OTA is alive and well, especially around big cities. To wit; I noticed this older TV antenna on the roof of a transmitter building in Lodi, NJ. Being curious, I connected an ATSC 1.0 TV to the antenna lead in the kitchen. One scan captured 62 TV channels and sub-channels OTA in the NYC market.
That site is 10 miles northwest of the Empire State Building.
I also noted that the satellite dishes on site have had Terrestrial Interference (TI) filters on the LNBs for many years. Recently, 5G filters were installed as well. Thus, I added a 5G/LTE filter made by Channel Master (part number CM-3201) to the TV antenna splitter. A rescan captured 79 channels. Interesting.
I began ordering TV receiver filters and testing them with my network analyzer. There are many different units made by different manufacturers. The smaller, cheaper units do not have as good performance as the larger, more expensive ones. Go figure.
Here are a few sweeps of various filters:
There is also an FM band-stop (Channel Master CM-3202), which is effective for blocking out 87 to 113 MHz.
Sometimes I get questions from non-technical readers, thus for the uninitiated; these sweeps are return loss. The higher the line on the right-hand graph, the less signal will get through the filter. A flat line at 0dB means that little or no signal is getting through on those frequencies.
These filters are helpful, especially with inexpensive consumer-grade TV receivers. If you live near an FM transmitter site, then an FM band-stop filter may help, especially with low and high-band VHF stations. If you live anywhere near a cell site (and most of us do) then a 5G/LTE filter will likely help.
Happy cord-cutting!
