Question: Recommendations for DTV signal measurement?

dboreham

DTVUSA Rookie
#1
Hello, I'm curious to hear recommendations on equipment to use in measuring received DTV signals when testing antenna configurations and aiming. I'm working on what seems to be a never-ending project to acquire usable signals for all the broadcast networks in my location. Many different antennas, mast heights, aim points etc have been tried with reasonable success eventually. I have one remaining signal left to pull in to complete the networks. Anyway, I've become rather frustrated with the difficulty I've encountered getting reliable and quick access to received signal data.

I do have a Spectrum Analyzer but it is very old with a hard-to-see screen (old-style analog storage tube) and impossible to see when I'm up on the roof pointing an antenna. I have several ATSC televisions and a Tivo box. These will report "signal strength" with some opaque units (40+ is good, I guess, typically). They do not report SNR nor do they do a good job with displaying physical channel, virtual channel and station ident. It is almost as if the designers of these devices had the goal to obscure as much information from the user as possible...

I'm wondering if one of the "USB DTV tuners" available for $50 or so has the capability to display all the technical received signal information including signal strength in dBuV, SNR, all the digital metadata from the media streams? What gear are folks here using? Professional test gear is beyond my budget but I did find this unit : http://www.solidsignal.com/pview.asp?p=DIGIAIR-PRO-ATSC the price is quite high but possibly justified in terms of the time saved climbing ladders... has anyone here tried this unit?

Thanks.
 
Last edited:

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#2
:welcome: dboreham

Great question and I was not aware of that particular tool. I forwarded the link to an Engineer-friend for his review. He uses a Sadelco meter which cost him over $3,000 years ago.

The unit you are looking at is a spectrum analyzer but it doesn't say it can display a specific transmitters' received waveform and with ATSC, that's the crown jewel for a tool. As you probably know, Signal "quality" (the waveform) is critical and signal strength hardly matters: even if there is a stable pilot signal, it doesn't mean the data flowing to your tuner can be deciphered. The ad says it reports BER and S/N, but (personally) I want a displayed waveform when I 'walk' an antenna to find its best location.

I'll get back to you after my friend responds.

Jim
 
T

the antenna tester

Guest
#3
I have one of these and I find it quite useful. Yes, the price is higher than a plain old signal finder but you get a lot of features that people here would probably enjoy. A typical signal finder is going to give you a couple of lights but this gives you real time measurement with real numbers in dBµV. You get SNR measurements too, if you don't see this feature when you get yours, simply upgrade the firmware although I'm guessing that all of them sold today have the new firmware.

You also get some very basic spectrum analyser features and the ability to lock into more than one signal at a time for comparison. The display is pretty simplistic but that probably helps with battery life.

I was influenced by this review: http://forums.solidsignal.com/conte...the-Digiair-Pro-ATSC-Signal-Spectrum-Analyzer ... I've followed this guy on several web sites and he really seeems to know his stuff.
 
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