• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

DTV reception question

gar hi

gar hi

So as I posted a while back, I'm able to get several TV stations from Hilo (they all actually originate in Honolulu) with an antenna mounted below the ceiling of my room.

Even being only 12 miles away and over 1,000 feet in elevation, a fairly good external antenna is needed to get anything.

The stations I've been getting are...

4.1 abc
4.2 MeTV
4.3 Hawaii news and weather
9.1 My TV network and local news
10.1 PBS
10.2 PBS
11.1 Fox
11.2 The CW
13.1 NBC
13.2 CBS
14.1 Religion and classic TV shows


So until about a month ago, most stations were strong and steady and never affected by the weather except 9.1 which would break up sometimes and 13.1 and 13.2 which only had a good steady signal under the right conditions but often would be just blank and said 'No Signal'.

Now, 13.1 and 13.2 have become strong and steady and never break up due to the weather but 11.1 and 11.2 are just like what 13.1 and 13.2 used to be.

There's been a complete reversal.

Is it possible that, for some reason, the actual radio frequencies were changed while the digital TV frequencies remained the same?
 
You can always do a rescan and test your theory or perhaps those stations are repacking or have otherwise reduced their signal strength. Give the stations a call or email and ask.
 
If your antenna is above the ceiling and out of view, could it be that it fell slightly or shifted and is now out of its original orientation> During my year as a teenager in Honolulu, we were within about five miles of all the local TV transmitters. The problem then/there wasn't lack of signals strength, but ghosts. Readjusting the rabbit ears was a constant activity. (VHF analog channels 2,4,9, & 13).
 
The antenna is firmly mounted the same way it would be as if it was on a roof, so I know it didn't move.

I remember 'ghosts' were a big issue on on UHF when I was growing up not far from Philadelphia.

We even had a separate high quality antenna in the attic for UHF and that still didn't get rid of them all.

Landtuna, I tried calling one of the stations when when many of our channels went off the air once but there was no department available to speak to that handled technical issues like that.

I'm wondering if they just switched transmitter locations, as there's more than one for the Hilo stations and they are miles apart.

I don't want to try moving the antenna because I took time to set it in just the right position that would be best for getting the most channels.
 
hawaiigar said:
Landtuna, I tried calling one of the stations when when many of our channels went off the air once but there was no department available to speak to that handled technical issues like that.
Click to expand...

The time to call is not during a major outage because you will want to speak with an engineering person. The front office will have no clue. Try calling when all is well and leave a message for the engineer to call you back (or use email). In my experience the engineers are most willing to answer questions if they are not elbows deep in a disaster.
 
I called again and like before, there's no menu option for engineering or anything technical related.

But I'm going to submit an email where there is an option for engineering/technical questions.

I will post when I get a reply.
 
I got a nice quick reply and they said they are doing repairs to the transmitter in Hilo.

Still don't know why 13.1 and 13.2 are now strong 24/7 unlike before but I'm not complaining.
 
It seems unusual that 13.1 and 13.2 would both carry major nets,
as the eye net and the peacock net are both major competitors.
 
So 11.1 and 11.2 were back to normal and now something else is going on.

I turned on the TV today and 4.1, 4.2, and 4.3 were all gone, not even in the channel presets anymore either.

What used to be on 4.1 is now on 13.2.

What used to be on 4.2 is now on 13.3.

What used to be on 4.3 is now on 13.4.

What had been 13.1 and 13.2 are gone and not relocated and 11.1 and 11.2 are off the air but still in the presets.

Is there another big DTV channel reassignment we don't know about?

I'm going to email channel 2 (which was on 11.1 here) like I did before and see what they know about it.
 
I did a new scan thinking I would find the now missing channels but no such luck.

What I did find was a new channel on 9.2 called 'Bounce'.

Never heard of that one before.
 
I didn't get a reply this time but I did another scan yesterday and all the channels are back and in their original locations again.

Anyone know why they would temporarily change the channel locations on the dial only to bring them back?

I don't know if they also changed the actual radio frequencies too.
 
Bunch of things all going on here at once:

First, the RabbitEars page linked above shows that nobody on the Big Island is repacking, save for one lone low-power station, K45CT-D, that operates on RF channel 45 and will have to move to a lower channel when 45 is removed from broadcast TV service next year.

Second, the explanation for why NBC and CBS are both seen on subchannels of KHBC-TV: it followed from an affiliation shuffle a few years back in Honolulu. Ownership caps didn't allow one company to own two stations in the same market if they were both among the four top-rated stations in the market. That kept the owners of NBC affiliate KHNL (channel 13) from buying CBS affiliate KGMB (channel 9). So they instead bought the independent station, KFVE (channel 5) - but then bought the "intellectual property" (callsign and programming) from KGMB and moved it to channel 5. Presto! In Honolulu, over-the-air viewers had to switch from 9.1 to 5.1 to see CBS. (On cable, KGMB/CBS stayed on 9)

But on the outer islands, it was complicated: KGMV (channel 3) on Maui and KGMD (channel 9) on the Big Island were licensed as satellites of channel 9 in Honolulu, and they had to continue to rebroadcast channel 9 in Honolulu - which ended up with KFVE's intellectual property. And so when you tune in "9.1" on the Big Island, you're getting KFVE programming now.

What to do with CBS? Well, KHNL had satellite stations on the outer island of its own, KOGG (channel 16) on Maui and KHBC (channel 2) on the Big Island. It was easy enough to simulcast the new KGMB/CBS 5 from Honolulu on the .2 channels of KOGG and KHBC.

There are satellite stations for the other old-line Honolulu stations, too - KITV (ABC/channel 4) from Honolulu had KMVI (channel 12) on Maui and KHVO (channel 13) on the Big Island, and KHON (Fox/channel 2) from Honolulu had KAII (channel 7) on Maui and KHAW (channel 11) on the Big Island.

But wait! There's another twist: when DTV started up a decade ago, it became possible to use virtual channels on those satellite stations to make over-the-air channel numbers all match up no matter where you are across the islands. So on the Big Island, viewers looking for ABC are still watching satellite station KHVO, which is still on RF channel 13 - but it uses virtual channel 4 to display "4.1" just like its parent station KITV in Honolulu. KHBC moved from RF channel 2 to RF channel 22 during the DTV transition, but now uses "13.1" just like its parent station KHNL in Honolulu. If you get PBS via any of several translators on the island, they all display as "10.x," matching KMEB on Maui, which they translate. Fox, for whatever reason, doesn't use its Honolulu "2.1" virtual channel on the outer islands - it's "7.1" on Maui and "11.1" on the Big Island.

Which brings us to what happened to you the other day. I suspect there were issues with one or more of the Big Island transmitters. In particular, it looks as though KHVO, the ABC affiliate, wasn't properly transmitting its PSIP data, the data stream that tells your TV how to remap the channels it's receiving. Without PSIP, your TV doesn't know that the signal it's getting on RF channel 13 is supposed to display as "4.1," "4.2," and so on. When that happens, some TVs will simply display the underlying RF channel - and presto, there's ABC on "13.1" instead.

And when that happened, the TV might still have been receiving KHBC on RF channel 22, complete with its PSIP stream telling your TV to remap its signal as "13.1" and "13.2"... but if it already had scanned in a "13" by way of KHVO, it simply ignored the higher channel, which is why NBC and CBS "disappeared." (Other TVs and tuners might instead have shown you two different "13.1" and "13.2" programs.)

Once KHVO fixed its PSIP encoder, you rescanned, KHVO's signals now properly mapped in as "4.1" and "4.2," and when the tuner got up to 22, it then properly grabbed KHBC as "13.1" and "13.2," and all was well in the world.

Make sense?
 
Thank You! That does make sense and I never thought the actual radio frequencies could show anything.

Before I did the final scan that got all the channels back in their proper positions, I was getting KGMB (that had been on 13.2) on channel 22.3.

One thing I have noticed about many of these over the air channel guides is that they are very outdated for Hilo and show channels in different locations than since I've been here.

The DTV frequencies are the same but the networks they show aren't the same and are still as you mentioned above.
 
Wow! KHVO wasn't transmitting their PSIP data? That's lost ad revenue. Fire that CE.
 
I still don't understand one thing, and this could happen in HI with a strong tropo inversion.
How would a receiver map two or more different RF channels that use the same PSIP numbers?
Also, how high can the number after the decimal be?
Ludwigent.com might never happen, but their plan is or was to have several dozen radio services as subchannels of TV stations, but with dedicated proprietary receivers
 
Last edited:
Depends on the receiver. Some (most, even) will simply scan in multiple stations with the same PSIP numbers, so you might get 2.1 (from station A), 2.1 (from station B), 2.2 (from station A), 2.2 (from station B), and so on as you move up the dial. Others will only scan the first instance of the major channel number, usually on the lowest RF channel.

In theory you can go up to x.99, though of course there's not enough data throughput in 6 MHz of ATSC 1.0 to handle that many subchannels.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom