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I've found a brand new evaluation board for the ATI/AMD T316 8VSB and QAM demodulator chip. It come with a Windows User Interface that interacts with the board over USB. Here's what it looks like on my PC:




The UI controls the tuner and show if there is MPEG-2 frame lock. Separate windows show the demodulator status and AGC status. I'm also running a DVB-ASI capture program (Enensys DiviCatch) and VLC to decode the MPEG-2 Transport Stream from the eval card.


I took some measurements on my strongest signal, KNTV-DT on RF channel 12. Here's the results:
Code:
Code:
Attenuation   Equalizer S/N         AGC%       # of Pre RS errors/sec
0  dB             32.0              40            0
10 dB             32.0              40            0
20 dB             32.0              43            0
30 dB             30.5              52            0
40 dB             24.3              61            0
43 dB             22.1              64            0
46 dB             19.7              67
 

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Where did you get it and for how much?
 

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Quote:
Originally Posted by otaguy /forum/post/15868992


What is this? Is it a prototype for a PC ATSC tuner card? Not yet available commercially?

Hi there


dr1394 already wrote that it's an evaluation board.

Eval boards are manufactured and sold by chip manufacturers to promote their chips to board and product designers/manufacturers. The eval board is used instead of having to start from scratch (on-paper design and then build a prototype). Eval boards tend to be expensive (compared to the chip that it's promoting). An eval board may incorporate some features of a reference design, but a reference design should be closer to resembling a real "product".


Regards
 

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I am aware that it is an evaluation board not a consumer product. I spent quite a number of years designing broadcast television equipment for GVG both as an employee and later as a contract engineer and would still like to get one if the price is not out of reason.
 

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Discussion Starter #6

Quote:
Originally Posted by Rory Boyce /forum/post/15869520


Where did you get it and for how much?

To be honest, I found it in a box at work. It was bought a couple of years ago when we were developing the ATSC capable DVD recorders for Panasonic (the EZ series). I'm not sure how much it costs, but as blue_z suggests, it's probably pretty expensive. Eval boards are typically priced very high to make sure you're a serious customer (and also because they are very low volume). Here's a photo of the set up:




The left board is the USB controller and Transport Stream I/O. The green cable is plugged into the DVB-ASI output. The center board is the T316 demodulator chip. The right board is the tuner and RF/IF strip. The tuner board is by far the most interesting as it contains several different AGC options (for different end product cost levels) and has a pretty good LNA chip, the Maxim MAX3538 (5 dB noise figure).

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/4494


There's also a Smart Antenna interface (not enabled):




And also a channel power display:


KNTV-DT



KCNS-DT



You can see the multipath distortion on KCNS-DT and the audio carrier of KNTV analog on the low end of the KNTV-DT plot.


The ATI/AMD demodulator product line has been bought by Broadcom. I searched the Broadcom website for the T316, and came up empty. It would seem that these boards are no longer available at any price.


Ron
 

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Quote:
Originally Posted by dr1394 /forum/post/15868157


I've found a brand new evaluation board for the ATI/AMD T316 8VSB and QAM demodulator chip. It come with a Windows User Interface that interacts with the board over USB.

Does that suggest that someone could construct a TV spectrum analyzer with a low budget USB interface?
 

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dr1394:


To bad its no longer available, it looks like your kludge would be useful to have around as a piece of test equipment. After seeing your first post I did some searching and come up empty for the T316. Your second post explains why. In the past I had to create my own test equipment more than once when designing various pieces of new television equipment.
 

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Discussion Starter #10

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Originally Posted by Tower Guy /forum/post/15877485


Does that suggest that someone could construct a TV spectrum analyzer with a low budget USB interface?

That's already been done. Just Google "usb spectrum analyzer". Lot's of products out there.


The power spectrum display on the T316 eval card is just showing the IF level at the demodulator after AGC. In the two pics I posted, the IF power is almost identical, but the the actual RF signals are about 40 dB different.


Ron
 

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Discussion Starter #11

Quote:
Originally Posted by Rory Boyce /forum/post/15881168


dr1394:


To bad its no longer available, it looks like your kludge would be useful to have around as a piece of test equipment. After seeing your first post I did some searching and come up empty for the T316. Your second post explains why. In the past I had to create my own test equipment more than once when designing various pieces of new television equipment.

I thought it would be interesting to show the hidden features that are available on these demodulator chips. Manufacturers could chose to include all of these measurements in their products, but of course they are much to "techie" for the average consumer. However, I'd have to say that the demodulator signal to noise ratio and the number of errors from the convolutional decoder are the most useful and should be included in all designs.


Ron
 

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Quote:
Originally Posted by dr1394 /forum/post/15881414


I thought it would be interesting to show the hidden features that are available on these demodulator chips. Manufacturers could chose to include all of these measurements in their products, but of course they are much to "techie" for the average consumer. However, I'd have to say that the demodulator signal to noise ratio and the number of errors from the convolutional decoder are the most useful and should be included in all designs.


Ron

My first DVB-T receiver, the Pace DTVA (which was a neat single cable design, where the Power and Antenna/Aerial feeds went into the main SCART connector that output RGB/Composite/Stereo/WSS to the TV, meaning only a single cable between box and TV) had two error displays when tuning. One showed the total number of errors, the other the number of uncorrectable errors remaining.


(*) Annoyingly this first gen DTVA is likely to be rendered obsolete when the UK switches off analogue TV, as the changes to the UK DVB-T model mean that some early receivers won't be compatible. Quite a major issue over here... On the other hand it will be 12 years old by then...
 

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Quote:
Originally Posted by dr1394 /forum/post/15881357


That's already been done. Just Google "usb spectrum analyzer".

Would you be so kind as to share your favorite model number? I'm looking for something in the high-end consumer price range.


There are plenty of true instuments with a USB interface in the 3K price range.


The Wi-Spy does 2.4 ghz only.


There are others from the UK with prices up near 1K US.


There's a sampling scope with a spectrum analyzer display, but it has a bandwidth of 100 mhz.
 

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dr1394,

Regarding HD spectrum analyzers, do you recall what computer capabilities were necessary for your plot (sublinked) of a stadium crowd scene using the free/low-cost shareware FFT software from SigView? You mentioned it was an uncompressed 4:2:2 YCbCr source. Notice you've recently added some 4:2:2 sources to your software site .


Surprised others haven't posted image analysis with SigView's program. One AVSer posted that he thought it only worked with audio(?)


Wonder if plots such as your SigView tryout are precise enough to make significant differentiations between the higher resolution content of standard in-home HD images?
 

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Discussion Starter #16

Quote:
Originally Posted by Tower Guy /forum/post/15883158


Would you be so kind as to share your favorite model number? I'm looking for something in the high-end consumer price range.


There are plenty of true instruments with a USB interface in the 3K price range.


The Wi-Spy does 2.4 ghz only.


There are others from the UK with prices up near 1K US.


There's a sampling scope with a spectrum analyzer display, but it has a bandwidth of 100 mhz.

I can't say I've ever used any of these USB based instruments. I have the luxury of HP and Agilent analyzers available to me at work. If $3000 is within your price range, you might be interested in this portable analyzer:

http://www.lptech.com/LPT-2250.html


I think it's around $2700.


Ron
 

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Quote:
Originally Posted by dr1394 /forum/post/15887493


I can't say I've ever used any of these USB based instruments.

I thought so.


I had tried the exact google search that you mentioned before your suggestion and didn't find anything cheap for measuring antenna signal strengths.
 

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Discussion Starter #18

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Darn, why are these fun toys never Linux-compatible? I'd have a new item for my wishlist if it was.


- Trip
 
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