Can't get the PBS station in my area on one OTA antenna

[zzjea]

I have 2 OTA antennas in the attic for separate TVs (due to db loss in a splitter, length, etc.). One of the yagi antennas finds every channel (55) except channel 8 (KUHT) PBS in Houston. I am about 40 miles from all the local Houston transmitters. The other antenna gets all the channels and KUHT is just fine. Why would I be missing just this one channel on the second antenna? I have tried to find the frequency for KUHT but is only shows VHF-Hi, not an actual frequency. The antenna receives all UHF and VHF frequencies in this area except for channel 8.

 

[rabbit73]

I have 2 OTA antennas in the attic for separate TVs (due to db loss in a splitter, length, etc.). One of the yagi antennas finds every channel (55) except channel 8 (KUHT) PBS in Houston. I am about 40 miles from all the local Houston transmitters. The other antenna gets all the channels and KUHT is just fine.

Hello, zzlea; welcome to the forum.

Kingwood, TX is a pretty big area; it has four zip codes:
77325, 77339, 77345, 77346.

Here is a sample signal report for a location in the Kingwood Village Estates, zip code 77345:
RabbitEars.Info

You can do your own report here (I use coordinates from Google maps):
RabbitEars.Info

It shows KUHT on real channel 8 (180 to 186 MHz), which requires an antenna for VHF-High. Tell us more about your two antennas.

CBS and ABC also are on VHF-High, but they are a little stronger than PBS.

You can use a distribution amp after an antenna to make the signals stronger before splitting.

Different locations in an attic will have different signal strengths.

 

[zzjea]

Thanks for the reply.
The antenna that works well is rather big probably 8 feet long and it does have a preamp (unpowered) and a corresponding line amp (Weingard). If I use a splitter with this antenna to another TV the signal is degraded (pixelates). I added the second antenna as I had it from when I used to mess around with HAM TV (years ago). It gets all the other channels except channel 8 (PBS). I have not found a frequency chart that shows exactly how 8 is being broadcast except for VHF-Hi. Where did you find the frequency for KUHT? I don't know if any of the ones I can receive are also on VHF-Hi to compare with. Just trying to understand why this one channel is missing. It shows as Fair from my location, but so does ABC and CBS however they may be UHF.

Channel	Callsign	Network (313974)	Community of License	State	Map	Transmitter Distance (Miles)	Direction (True)	Direction (Magnetic)	Field Strength (dBuV/m)	Signal Margin (dB)	Repack Info
2‑1 (35)​	KPRC-TV	NBC	HOUSTON	TX​	​	40.4​	209.3°​	207.3°​	98.64 Good​	57.87​	​
39‑1 (34)​	KIAH	CW	HOUSTON	TX​	​	40.4​	209.3°​	207.3°​	98.63 Good​	57.95​	L​
20‑1 (19)​	KTXH	My	HOUSTON	TX​	​	41.1​	209.7°​	207.7°​	98.40 Good​	59.15​	​
67‑1 (36)​	KFTH-DT	UniMás	ALVIN	TX​	​	40.6​	210.2°​	208.2°​	98.17 Good​	57.31​	​
14‑1 (24)​	KETH-TV	TBN	HOUSTON	TX​	​	40.6​	210.2°​	208.2°​	98.13 Good​	58.37​	​
57‑1 (31)​	KUBE-TV	IND	BAYTOWN	TX​	​	40.6​	210.2°​	208.2°​	98.11 Good​	57.69​	L​
45‑1 (30)​	KXLN-DT	UNI	ROSENBERG	TX​	​	41.1​	209.7°​	207.7°​	98.02 Good​	57.7​	L​
47‑1 (22)​	KTMD	TLM	GALVESTON	TX​	​	40.6​	210.2°​	208.2°​	97.80 Good​	58.24​	L​
26‑1 (26)​	KRIV	FOX	HOUSTON	TX​	​	39.9​	209.1°​	207.1°​	97.71 Good​	57.76​	​
55‑1 (33)​	KTBU	IND	CONROE	TX​	​	41.1​	209.7°​	207.7°​	97.49 Good​	56.89​	L​
51‑1 (25)​	KYAZ	Azteca	KATY	TX​	​	41.1​	209.7°​	207.7°​	96.83 Good​	56.98​	L​
49‑1 (32)​	KPXB-TV	ION	CONROE	TX​	​	40.9​	209°​	207°​	96.53 Good​	56.02​	​
61‑1 (21)​	KZJL	Estrella	HOUSTON	TX​	​	41.1​	209.7°​	207.7°​	96.27 Good​	56.81​	L​
22‑1 (23)​	KLTJ	Daystar	GALVESTON	TX​	​	40.6​	210.2°​	208.2°​	92.78 Good​	53.12​	​
11‑1 (11)​	KHOU	CBS	HOUSTON	TX​	​	40.9​	209.1°​	207.1°​	78.34 Fair​	42.34​	​
13‑1 (13)​	KTRK-TV	ABC	HOUSTON	TX​	​	39.9​	209.1°​	207.1°​	77.16 Fair​	41.16​	​
28‑1 (28)​	KUGB-CD	IND	HOUSTON	TX​	​	40.6​	210.2°​	208.2°​	75.86 Fair​	35.72​	​
8‑1 (8)​	KUHT	PBS	HOUSTON	TX​	​	40.6​	210.2°​	208.2°​	75.04 Fair​	39.04​

 

[Jim5506]

On the Rabbitears chart the number after the XX-1, in parenthesis is the frequency, so channel 8-1 broadcasts on VHF channel 8.

ABC and CBS are also VHF, on channels 11 and 13.

At 40 miles you are probably fortunate to receive channel 8 on the other antenna. You need to get those antennas out of your attic and up in the air.

Rough estimate for attic signal loss is about 50%, so it is equivalent of already having a splitter installed, maybe worse depending on roofing materials.

Here is a chart of USA TV channels and the associated frequencies. TV channel frequencies | VHF,UHF TV channels 2 to 69

Please note that most channels do not use the same RF channel as they use as their call sign, for instance NBC in Houston is channel 2-1 but broadcasts on channel 35 RF (radio frequency). Digital TV introduced these virtual channel to us. All this information is in column one of the chart Rabbit Ears showed and you duplicated in your post.

 

[rabbit73]

The antenna that works well is rather big probably 8 feet long and it does have a preamp (unpowered) and a corresponding line amp (Weingard). If I use a splitter with this antenna to another TV the signal is degraded (pixelates)

That big antenna probably has elements for VHF channels. An unpowered preamp acts like an attenuator that will weaken your signals.

I added the second antenna as I had it from when I used to mess around with HAM TV (years ago). It gets all the other channels except channel 8 (PBS).

That antenna probably has elements that are too short for VHF channels; only good for UHF RF channels 14 and above.

I have not found a frequency chart that shows exactly how 8 is being broadcast except for VHF-Hi. Where did you find the frequency for KUHT?

I use a chart similar to what Jim5506 showed you for the real RF channel.
Pan-American television frequencies - Wikipedia

Just trying to understand why this one channel is missing. It shows as Fair from my location, but so does ABC and CBS however they may be UHF.

PBS is a little weaker than ABC and CBS. As Jim mentioned, the signals in the attic will be weaker than listed on the report. Also, any trees outside in the signal path will make the signals weaker.

Thank you for the signal report.

You are in the area of coverage for KUHT, but there are some weak signal spots around your location. I have removed the marker for your actual location.

I don't know how to delete this:

�

 

[rabbit73]

Just trying to understand why this one channel is missing. It shows as Fair from my location, but so does ABC and CBS however they may be UHF.

ABC and CBS are also VHF.

ABC is on Real channel 13 (210-218 MHz) and CBS is on Real channel 11 (198-204 MHz).

The yellow background on the report for those channels indicates VHF-High.

 

[rabbit73]

I have not found a frequency chart that shows exactly how 8 is being broadcast except for VHF-Hi. Where did you find the frequency for KUHT?

If you use an SDR, you can actually see the frequency of a channel. The least expensive SDR is the RTL-SDR.COM V3 (about $30).
Buy RTL-SDR Dongles (RTL2832U)

With it and DIY free software from GitHub you can see VHF-High:

or just one channel:

If you don't want to mess with the DIY software, you can use SDR# (SDRsharp) software, but you will only be able to see about 2 MHz of a channel at once:

If you use an SDRplay RSP1A SDR ($100) and SDRuno software, you can see a whole channel:

If you use an Airspy R2 SDR ($200) and SDR# software, you can see a whole channel:

and with the Spectrum Spy software you can see all of VHF-High:

or all of UHF: