Which Set Top Tuner Now??? (2 Viewers)

rabbit73

SatelliteGuys Family
Jul 17, 2020
111
66
S.E. VA
I have been playing around with the 27-2 channel, and today they are showing 55-58% quality, although there is not any Video or audio.
The other 27-xx channels are all showing the same quality, along with normal video and audio. Do they have a sub-carriers on these
digital channels for a marker?? I'm beginning to understand that I don't understand all this HD-digital transmission particulars.
BR
All of the subchannels are combined on just one transmitted channel. If all the other subchannels are OK, but 27-2 isn't OK, then the problem is not with the transmitter, it's with the network content feed from VIDORTV.
 
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rabbit73

SatelliteGuys Family
Jul 17, 2020
111
66
S.E. VA
The other 27-xx channels are all showing the same quality, along with normal video and audio. Do they have a sub-carriers on these digital channels for a marker??
There is a pilot carrier that is for the whole channel and all of its subchannels. The tuner locks on to the pilot carrier.

1-9-21 CH11 test2 29884 near window10in_1.jpg


If the pilot carrier is damaged, it is difficult for the tuner to lock on to the pilot:

1-9-21 CH11 test1 29884 back from window19in_1.jpg


Being able to see the shape of the signal and monitor the signal quality (SNR on SONY) allowed me to find the best location for the CH11 antenna. CH11 (ABC) is my weakest channel. It's on VHF-High where I have a high noise level that reduces the SNR.
 
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rabbit73

SatelliteGuys Family
Jul 17, 2020
111
66
S.E. VA
Knowing the SNR or signal quality of an OTA channel can be very helpful when comparing antennas or finding the best antenna location.

Since many TVs don't show SNR or signal quality, I did a comparison between SNR on my SONY TV and Signal Quality on the Mediasonic-HW-150.

TV SNR and HW150 SQ 100pct_2.jpg


Here are the screenshots of the CH16 signal at SNR 31, 24, and 15 dB:

1-24-2021 CH16 Test1 NoAtt_1.jpg


1-24-2021 CH16 Test2  Att30_1.jpg


1-24-2021 CH16 Test3 Att30andVar_1.jpg


And here again is the HW-150 screenshot of CH20 at the Digital Cliff:

MediasonicHW-150 CH20atDigitalCliff_2.jpg
 
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Benny-W5TYZ

Thread Starter
SatelliteGuys Family
Dec 1, 2020
40
10
Orange, Texas
Knowing the SNR or signal quality of an OTA channel can be very helpful when comparing antennas or finding the best antenna location.

Since many TVs don't show SNR or signal quality, I did a comparison between SNR on my SONY TV and Signal Quality on the Mediasonic-HW-150.

View attachment 150107

Here are the screenshots of the CH16 signal at SNR 31, 24, and 15 dB:

View attachment 150103

View attachment 150104

View attachment 150105

And here again is the HW-150 screenshot of CH20 at the Digital Cliff:

View attachment 150106


Wow, that's some good info Rabbit....I have copied the attachments for my "Notebook"...I finished the Fractal antenna this morning and I'm going to try to post some pictures. In the photos, you will see that it is placed on top of my TV Cabinet. I also posted the scan showing the total found. It is 17, which is about the same as those "File Folder" antennas you can purchase for around 15-20 bucks. I also included a radio I built from 1925 Popular Mechanics. It is an 8 tube (401A's) Superhetridyne and all of the components that were required in 1925-26 which were the issues that it was featured in. It took about 3 years to find everything. Going back to the Fractal antenna, I think it would be OK if you just wanted to build your own antenna to receive programming, but i am going to try a balun and see if it makes any difference. Right now I am feeding it with 300-ohm twin lead, connected to a short run (2FT) of 75 ohm to the TV. I'm not going through the 150, just straight to the TV. I built it just because I was curious.....

The web site says my photos are too big to post what do I do now???

Benny - W5TYZ
 

Benny-W5TYZ

Thread Starter
SatelliteGuys Family
Dec 1, 2020
40
10
Orange, Texas
Wow, that's some good info Rabbit....I have copied the attachments for my "Notebook"...I finished the Fractal antenna this morning and I'm going to try to post some pictures. In the photos, you will see that it is placed on top of my TV Cabinet. I also posted the scan showing the total found. It is 17, which is about the same as those "File Folder" antennas you can purchase for around 15-20 bucks. I also included a radio I built from 1925 Popular Mechanics. It is an 8 tube (401A's) Superhetridyne and all of the components that were required in 1925-26 which were the issues that it was featured in. It took about 3 years to find everything. Going back to the Fractal antenna, I think it would be OK if you just wanted to build your own antenna to receive programming, but i am going to try a balun and see if it makes any difference. Right now I am feeding it with 300-ohm twin lead, connected to a short run (2FT) of 75 ohm to the TV. I'm not going through the 150, just straight to the TV. I built it just because I was curious.....

The web site says my photos are too big to post what do I do now???

Benny - W5TYZ
 

Benny-W5TYZ

Thread Starter
SatelliteGuys Family
Dec 1, 2020
40
10
Orange, Texas
OK I'm gonna try this again...Standby....
 

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rabbit73

SatelliteGuys Family
Jul 17, 2020
111
66
S.E. VA
Wow, that's some good info Rabbit....I have copied the attachments for my "Notebook"...
I'm glad you found some of my ideas useful, Benny.

The description of the superhet is interesting.
I finished the Fractal antenna this morning and I'm going to try to post some pictures......The web site says my photos are too big to post what do I do now???
I couldn't find a maximum size listed. I try to keep the width less than 1000 pixels.
 

Benny-W5TYZ

Thread Starter
SatelliteGuys Family
Dec 1, 2020
40
10
Orange, Texas
I finally found a photo resizer for the Mac-OS, and I just knocked them down to 600 X 600, so I could probably go a little larger. However, if you click on the first photo, it will enlarge, and there is an advance arrow that lets you see all the pic's without having to reset eveyone...

Benny - W5TYZ
 

Benny-W5TYZ

Thread Starter
SatelliteGuys Family
Dec 1, 2020
40
10
Orange, Texas
View attachment 150119

Thanks for the photos. Nice job on the radio, Benny.
I haven't built the antenna for it yet. There are plans for a collapsable Loop Antenna that sticks out the top of the radio and it has a 360 degree map so you can keep up with your stations.....If you don't move the radio to another spot. In one of the other photos, on the right side of the radio, you cans see the multiple headphone connection. Everyone in the family could have thir own headphone. It also has a 3-10 watt speaker amp, incase you culd find a horn. If not, grab the haedset.....
 

rabbit73

SatelliteGuys Family
Jul 17, 2020
111
66
S.E. VA
The web site says my photos are too big to post what do I do now???

Benny - W5TYZ
The first attachment is 1366 x 768 pixels, 338 KB.
The second attachment was 2581 x 2046, 1.07 MB; the forum software reduced it to 1363 x 1080, 275 KB.

I answered your conversation about SDRs.
 

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rabbit73

SatelliteGuys Family
Jul 17, 2020
111
66
S.E. VA
The picture you sent what is the knob with the 2 coax's attached and a dial 1-10. Also what is the ivory colored item, wedged shape with 3 coax's going into it. You need a bigger TV tray.
I picked those two photos for their size for a test. The first one is a full screen shot from my 15" laptop. It shows what can be done with the SDRplay RSP1A and SDRuno software.

The larger second one was shot with my old Canon digital camera. It shows the setup for a tuner overload test.

The device with the 0-10 knob is a 0-10 dB step attenuator. The ivory wedge shape item is a Channel Master 3410 amp with 15 dB gain. The three amps are in series for 49 dB gain when the attenuator is at zero.

This is what the photo looked like after I had reduced the size and added notations.

CM7777hdOverloadNormalV.jpg
 
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Benny-W5TYZ

Thread Starter
SatelliteGuys Family
Dec 1, 2020
40
10
Orange, Texas
When I was in the Air Force, I was assigned to a TDY (Temporary Duty ) assignment where we were doing some very sensitive stuff, and your setup looks like some of the stuff we did, known as a Kluge Board. That was the first time I found out you could send Ultra high RF through a square pipe just like water Nuff said on that...It was over 50 yrs ago, and now we have Stealth weapons.....
 
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rabbit73

SatelliteGuys Family
Jul 17, 2020
111
66
S.E. VA
OK, Someone else might be curious too....BTW what is the brand of the step attenuator?
It's a Wavetek Step Attenuator 7510A. I found it on e*b*a*y in like-new condition at a good price.

but I had to buy 2 adapters:

Pomona 6779 Adapter_1.jpg
 

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