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WPVI-DT 06 Testing?
- Thread starter tripinva
- Start date
How would they do that and continue broadcasting on channel 64? I know that WPVI-DT is moving from 64 to 6 in Feb. Can the old transmitter be used to broadcast a digital signal instead of an analog one, or would they have to change the transmitter broadcasting on channel 64 to broadcast on 6? What is going to happen to 1/2 of the TV transmitters in the country next month? Can tey be used as backups?
Bill_W said:
A UHF transmitter generally can't be repurposed to broadcast on VHF, and vice-versa - but an analog transmitter of recent vintage can certainly be repurposed to broadcast a DTV signal, and pretty easily at that.
A modern TV transmitter consists of an exciter, which generates a very low-power signal, and an amplifier that boosts that low-power signal to full output power. In some cases, that's a tube-based amplifier, in others, a solid-state amplifier that consists of dozens of individual modules.
It's common, in these waning days of analog, to see a station drop to half-power on analog - and what it's doing while dropping to half-power is taking half of the amplifier section of its analog transmitter out of service and connecting a digital exciter to it. Once that work is done, the station has a digital transmitter all ready to go (DTV power levels are generally much lower than the analog), and then it just has to switch that transmitter into the line in place of the remaining half of the analog transmitter. That's likely what's happening at WPVI.
Once the conversion is done, stations like WPVI-DT will likely sell their UHF transmitters to other stations that need them (or even transfer them within ownership groups - I think ABC has at least a few DTs staying on UHF) and then convert the other half of the V transmitter as a DTV backup.
Technically, WPVI could transmit digitally on 6 and 64 at the same time - separate transmitters and even, in this case, separate towers - but some converter boxes might not like finding two stations using "6" as their virtual channel at the same time. I wonder if they used a different virtual channel during the testing?
They've already installed a brand new channel 6 DTV transmitter. Since they'll be using the existing antenna, they can test their final signal just as many other stations have.
Some old transmitters can be reused for digital, but older ones cannot--many of the newer analog transmitters will become backup digital transmitters.
A UHF transmitter can't transmit a low-VHF signal. Well, it probably can, but it'll do a really lousy job. Better off reselling the channel 64 transmitter and retuning it for a lower UHF channel.
Many transmitters will probably end up shipped off to Mexico, where they don't go digital until 2022.
As for Scott's comment, I know of a few stations which have done overnight testing and set up a separate subchannel. For example, WKRC-DT in Cincinnati tested their VHF-12 signal by mapping to 12-3, which didn't conflict with the channel 31 digital mapping to 12-1 and 12-2. ABC has only one UHF station, KFSN in Fresno. Everything else they own will operate on VHF, so they'll very likely end up selling their current digital transmitters.
- Trip
Some old transmitters can be reused for digital, but older ones cannot--many of the newer analog transmitters will become backup digital transmitters.
A UHF transmitter can't transmit a low-VHF signal. Well, it probably can, but it'll do a really lousy job. Better off reselling the channel 64 transmitter and retuning it for a lower UHF channel.
Many transmitters will probably end up shipped off to Mexico, where they don't go digital until 2022.
As for Scott's comment, I know of a few stations which have done overnight testing and set up a separate subchannel. For example, WKRC-DT in Cincinnati tested their VHF-12 signal by mapping to 12-3, which didn't conflict with the channel 31 digital mapping to 12-1 and 12-2. ABC has only one UHF station, KFSN in Fresno. Everything else they own will operate on VHF, so they'll very likely end up selling their current digital transmitters.
- Trip
No, WHYY is at reduced power because Qualcomm wanted the DT-55 they originally were assigned for their "MediaFLO" service and paid off WHYY to move to channel 50, which has to protect WNJN-50 in Montclair as well as WTVE-51 Reading and WWSI-DT 49 in Atlantic City.
WHYY-DT will be reverting to channel 12 and maybe using the same transmitter, but that's not why they're at low power now.
- Trip
WHYY-DT will be reverting to channel 12 and maybe using the same transmitter, but that's not why they're at low power now.
- Trip
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