May 27, 2021 at 10:05 pm #50679
I’m only 16~18 miles away from the UHF transmitters. Just over the top of a hill too. On a windy day the low powered ones would be all over the place signal wise. I had to put up a fringe antenna to get solid signals from them.May 28, 2021 at 2:36 pm #50681Alfredo_TParticipant
There used to be some interesting Web sites chronicling the disastrous history of early UHF television. I think that one was called The UHF Morgue. According to one of these sites, the first generation of UHF television station licensees discovered that shadowing of their signals by hills was a serious problem. In my recollection, one station in the Allegheny Mountains raised its ERP almost to one million Watts, only to discover that they put a really great signal to very sparsely populated areas on hilltops, yet the people in the towns that they were trying to reach still received lousy pictures.
Elsewhere, I read that when KPTV was still on UHF, an apartment complex that was geographically close to the transmitter had sub-par signal strength throughout most of the complex due to shadowing. To allow its residents to watch TV, the complex had to jump through some technical hoops. A UHF receiving antenna was mounted at a location that had a clear line of sight to the transmitting tower (if memory serves me correctly, this was a few hundred feet from the apartment buildings). The KPTV signal was down-converted to VHF and then sent through a network of splitters and transmission lines for delivery to apartment units.May 28, 2021 at 2:49 pm #50682lastdayParticipant
I vaguely remember when UHF was rolled out in the greater Los Angeles area. UHF stations were always problematic reception-wise. Early TVs equipped with UHF support had to be tuned kind of like an analog radio. Locating stations was challenging if the TV’s primitive UHF tuning mechanism wasn’t calibrated very well.
Anyway that’s what I remember.May 28, 2021 at 7:32 pm #50684
Or, a TV Service person would install a UHF tuning strip in an unused VHF channel slot of your mechanical tuner. Those were very marginal at best.May 29, 2021 at 12:21 am #50687
Maximum power of an analog UHF station was five million watts, so one million was just scratching the surface!May 29, 2021 at 8:02 am #50691Master of DisasterParticipant
The Master of Disaster remembers once having an old TV and VCR with “presets” tuned with a different three-way switch and a thumbwheel, also included a pack of adhesive channel numbers for each “preset”. Think it was called a “varacator tuner” or something like that; search engines seem to think the Master of Disaster has no idea what he’s talking about and instead pitch products and services unrelated to anything.
Thought they were kinda cool in a way, but probably too technical for a lot of people. Also, this was obviously well before channel ID bugs, so sometimes one would think they’re watching a given channel only to find out they’re actually tuned to another.May 29, 2021 at 8:12 am #50692lastdayParticipant
Lastday remembers exactly what MoD is describing. I had a TV with (as I recall) about 10 adjustuble presets that (again as I recall) could be tuned to any VHF or UHF station. Maybe it was just UHF. Anyway you had to manually dial in each preset with a knob or a tool and then label what it was. It was referred to as varactor tuning. I want to say it was a Sony but I’m not positive.
Edit: It was similar to this Emerson. Patents for variations on varactor tuning in TVs were filed by Magnavox, Zenith, RCA, and others.
May 29, 2021 at 9:56 am #50694jr_techParticipant
- This reply was modified 4 months, 3 weeks ago by lastday.
Early Zenith promo film touting the merits of their UHF conversion scheme:May 29, 2021 at 12:59 pm #50695
They came preset for channels 2-13 and you could change any of them and switch labels. They were also used on VCRs.May 29, 2021 at 5:50 pm #50697stevewaParticipant
Yes I remember the UHF tuners, which used a slot between 2 and 13 on the mechanical VHF tuner, and a reduction dial (so it took many revolutions to move between 14 and 83) for the actual UHF tuning. Always a dubious proposition to get a signal. I remember loops and “bow-tie” clip-on antennas for UHF that you would use with your rabbit-ears.
Totally confirm the setup on early VCRs as well.May 29, 2021 at 6:58 pm #50698nosignalallnoiseParticipant
(Tags: applications, can you hear me now?, construction permits, DXing, FCC, grants, programming logic, static, towers, What the hell happened?, UHF)
nosignalallnoise also remembers the VCRs and televisions Master and lastday are talking about. My grandparents bought a JC Penney’s HIFI VHS deck with 12-position (IIRC) varactor tuner and they used it until it finally died in the mid 90s. The TV in the playroom was a 27″ Quasar with that same kind of tuner, only labelled “A” through “K”. Grandmum actually still has that TV but last I had it on its CRT was so spent, it barely produced a usable picture. Too bad I don’t have a Super Mack that I could blast the shit out of it with.
I used to play with the TV’s UHF section quite a lot during AMPS’ heyday…..
And people, PLEASE learn how to use the tags properly.May 30, 2021 at 8:57 pm #50704e_dawgParticipant
Speaking of the old channel 27. Why did KHTV failed? Did manufactures at that time have both VHF/UHF turner for Portland tv market? I know from 1959 to 1981. Portland tv market was VHF only until KECH 22 signed on in 1981.May 30, 2021 at 10:48 pm #50705
Actually Portland had one of the first UHF stations in the country. Posted above by Jr_techMay 31, 2021 at 12:29 am #50706
Portland had the first UHF station in the world!May 31, 2021 at 8:56 am #50710nosignalallnoiseParticipant
Bridgeport, CT had the first UHF TV station in the world, on an experimental basis, simulcasting WNBT on channel 24. When it proved successful and the experiment concluded in 1952, Empire Coil bought the transmitter and had it shipped to Portland where it operated full-time as a commercial broadcaster.
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