what I have noticed about my LG TV (probably same vintage as ur 2009) is that when just below lock threshold, you won't see any indication of a "sniff" so to speak. Makes it difficult to determine if your close.
Whereas other tuners just below lock threshold will at least indicate something. I'm very happy it's performance though. Quite often when DX'n it'll pull in stuff the Zenith DTT-901 (which is a pretty good tuner itself) is just barely getting a sniff of.

ATSC Tuners can have different performance due to several different factors:

1) Sensitivity - The older Samsung could be a couple or a few dB less sensitive.
NAB did a test on 6th Gen CECB's (so all same generation, many with the same parts)
showing only small differences, but older DTVs are probably less sensitive. Note that
loss of sensitivity did NOT correlate very well to the number of OTA stations missed:
http://www.nabfastroad.org/NABSTVDigitalConverterBoxEvaluation/DigitalConverter.asp

2) Multipath Tolerance - The older Samsung probably has difficulty handling
severe Multipath situations, which many times will require a higher S/N to overcome.

The Field Ensemble Test in ATSC A/74 specifically addresses this issue:
http://www.ntia.doc.gov/dtvcoupon/dtvmanufacturers.pdf
http://www.atsc.org/cms/index.php/standards/recommended-practices/180-a74-receiver-performance-guidelines?format=pdf

3) [B]Adjacent, Next-Adjacent & "Taboo" Channel Susceptibility - 6th Gen Tuners have
improved the ability to operate in the presence of stronger signals on nearby channels.
The FCC's OET group tested numerous 2005/2006 DTVs + STBs, finding significant
performance differences. We have NOT seen any recent retests, but WOULD expect to
still see differences among 6th Gen and later Tuners:
http://transition.fcc.gov/oet/info/documents/

4) Resistance to "Overload" - When you have multiple strong signals going into
a Tuner, InterModulation noise Distortion (IMD) WILL be generated...and sometimes
they will fall on top of weak signals. Different Tuners will behave differently.....

Which is why it is tricky to find the "optimum" balance of Antenna Gain, Downlead loss,
Distribution Gain and final Coax Feed loss which will allow operation with a
maximized Spurious Free Dynamic Range (Search: "SFDR"):
http://www.arl.army.mil/arlreports/2007/ARL-TR-4235.pdf [See Fig 3]
http://www.fiber-span.com/Application_Note_Spurious%20Free%20Dynamic%20Range.pdf
http://www.odyseus.nildram.co.uk/Systems_And_Devices_Files/Linearity.pdf

How can you improve the Samsung's reception (other than replacing it as you have done)???
You could try readjusting the SFDR "balance"....again....perhaps by inserting a variable RF
attenuator on it's input (only a few dB is needed, since each 1 dB causes 3 dB drop in IMD).
Feeding it with a separate antenna (no splitters) for sure will be an improvement.....

Many thanks for that very careful explanation. Exactly the stuff I was wondering about. BTW, the 22 inch TV wasn't bought to replace the large Samsung (which we are stuck with in the living room) but as a laptop monitor and spare TV - but kind of skeptical it makes a good monitor locking in at 1080p.

Now each source of impairment has a different fix (or no fix at all). On a bad night when the Samsung Buffalo reception is borderline, my gut feel is that the main issue is signal strength and sensitivity.

Here's my amateur take:

1. sensitivity might be helped with pre-amplification

2. multipath might be helped with antenna aiming

3. channel interference with antenna aiming and channel filters

4. overload from local stations with channel filters or broadband attenuators (as holl_ands mentions)

I have a 4-way splitter built into an 8dB-gain distribution amp. Of those, my pick for my situation would be pre-amplification. But since I am close to overload already, it should make overload worse... for no net gain in reception quality.

Hope that's not all the fixes possible because even the most likely options, #1 and #4, seems unlikely to be profitable.

I think I'll give #4 (adding attenuation to reduce IM) a try by putting another splitter or two in the antenna signal path.

Ben

My father has a Sony kdl40s4100, we have did a scan for channels and found a fair bit, but cannot seem to figure out how to do a manual channel scan for when the antenna is turned.
I was wondering if anyone had any idea on how this may be done.

As a side note I have a somewhat older RCA and it had a nice feature called "Channel Update" so you could do an auto scan and not lose what you previously had found. so was also wondering if any newer tvs still had functions like this?

Thanks in advance

octopod i have a KDL-40s3000 i think is just a few years older than your fathers tv, on mine when you go on the menu to channel theres mutliple options, auto program - clears all your old channels and scans for analog and digital channels, but the one you want it add digital channels - it scans for new digital channels and doesn't erase your old channels so when you turn your rotor you then just rescan your digital channels and it will add any new ones. Hope this helps!

i tried a recent model Sony (2011) and the recent Samsung LED series 5000 (2011), in both cases my LG (2009) outperformed them in terms of tuning into weak 2nd edge channels, BUT the Zinwell ZAT 720 converter beat all TVs tried so far in that respect.

I tried to do an antenna install last week, for my brother's new TV, and could not get a single digital station. I brought the antenna and cable home and tested on my TV and it wrks great, so I know there's nothing wrong with my antenna balun or the cable.

The TV is a Dynex DX-40L260A12. Scans always came back with zero digital stations. However trying to manually go to the RF channel of a station he should get (21-1), would cause the TV to switch to 21-1. It would also do this for other RF assignments that should be coming in. The TV would refuse to switch to other digital channels, where no signal should be present.

It must have been detecting some signal on those stations that it successfully switched to, but they all resulted in black screens, and the TV's signal strength menu would show 0% constantly. If it's always 0%, why did it switch to those stations, but would refuse to go to others with no digital signal broadcasting in the area?

Does anybody have this TV, and how have you found the built in tuner to perform?

Possible he has a dud TV tuner?

The TV is a Dynex DX-40L260A12. Scans always came back with zero digital stationsx4mer I have to wonder about the Dynex tuners, given that the brand is at the low end of what FS/BB sells. Unless someone tells us otherwise (based on their excellent experiences in a fringe to deepest fringe area) I have to say that the few reviews we've seen here at this site about ATSC tuners in Dynex TVs are not good.

See Post #680 (http://www.digitalhome.ca/forum/showpost.php?p=1282094&postcount=680) in this thread for another owner who could not scan in any digitals. Also check out these posts from other threads that contain similar info:

http://www.digitalhome.ca/forum/showpost.php?p=1204247&postcount=892

http://www.digitalhome.ca/forum/showpost.php?p=1124058&postcount=621

Just to be fair, are there any Dynex owners here who are satisfied with the ATSC tuner's performance?

Just to follow up on my experience with the Dynex, I ended up getting a Nexxtech amp from the Source to connect to the indoor antenna and that got me all the local channels plus the ones from Bellingham. This was the first time for me that an amp actually improved the reception. The fact that an amp improved the reception shows that the Dynex tuner has very little, if any, built-in amplification. I learned on these forums that all tv tuners have some sort of a built-in amplifier.

Hey guys,

I have a 42 inch Samsung plasma tv. On the samsung website, it says that my TV has a DTV tuner built-in. I don't have any tv subscription with any company. I just watch the free channels like CTV or CBC. Would I need to purchase a converter box, and if yes, can anyone recommend one?

This is the samsung website specs: http://www.samsung.com/us/video/tvs/PN42C430A1DXZA-specs

I'm living in an apartment with a coaxial cable input in the wall, but when I plug my tv straight into that I don't get anything. I've been using rabbit ears for a year or so.

Thanks a lot in advance!

Under "Tuner" it states "ATSC/Clear QAM" therefore you don't need a converter box. Just plug the antenna coax into the tv and scan the channels (however that is done with that particular model).

Thanks mr weather! That helped since now I know I don't have to buy another box + remote to add to my collection.

In the frenzy of new digital channels coming on board last couple of days and my experience and another post regarding scanning for additional digital channels, I was wondering about something.

On Monday when I looked for Global digital on 6.1 by going through the "add digital channel" feature on my Sony, it would not pick up Global. Yesterday, I did the same thing looking for TVO on 24.1 and the channel was found. When I was changing channels with the remote, Global on 6.1 all of a sudden appeared.

Another person on the CHCH thread experienced something similar in that when he used the add digital channel feature, his tv (he mentioned having both a Sony and Toshiba) did not pick up CHCH on 11.1. Only when he did a full scan did the channel appear.

This led me to thinking when scanning for additional digital channels, does it only scan the uhf channels and not the vhf? Or are these experiences a mere coincidence?

Was out lookin around for a monitor.. figured why bother with a monitor?
Wound up with a Low end 22" LCD TV up to 1080P res, two hdmi inputs, component input, VGA Input (what I'm using) plus an ATSC Tuner, which so far isn't half bad, just crappy signal reporting, etc.

Was out lookin around for a monitor.. figured why bother with a monitor?
Wound up with a Low end 22" LCD TV up to 1080P res, two hdmi inputs, component input, VGA Input (what I'm using) plus an ATSC Tuner, which so far isn't half bad, just crappy signal reporting, etc.
Funny thing, I did exactly the same a month ago. But my Vizio has a far better tuner than my 3 yr old Samsung plasma 42 inch.

Thanks to the nice engineers at Apple, automatic connection at 1080 using the mini-DVI/HDMI connector. But I am still not sure if it really works better on text than a purpose built monitor running high res feed.

Undocumented surprise: like a monitor, my Vizio TV turns off if there is no signal for a few minutes.

^^^^
My 2.5 YO Sharp Aquos also turns off with no signal. However, that's mentioned in the manual. I suspect more and more sets will have that, in the interest of power efficiency, if not already required by law.

Likewise on this thing i just bought. It has an option to turn that feature off.
Haven't played with it yet though to see how it behaves.
The tuner in this low end TV probably isn't the best out there, as it seems to lose lock before the Zenith Dtt-901 CECB does on weak signals, but still seems to be pretty good, definitely usable.
I've done some scans side by side with the Zenith (pretty good tuner). Seems to catch the same channels
as the CECB upon each scan.

Also noticed the PSIP guide actually works while tuned to CBLT, CBC.
So, this is the first TV or CECB I've ever used where the guide actually worked while on CBC.
Figures it would work on the cheapest TV I could find. Interesting...

On my new LG TV I have to go into the "manual channel add" option to find out what the signal strength and signal quality are. Does anyone know if there are more diagnostic options (like SNR for example) available on an LG TV?

I've got a Panasonic Viera Plasma.

It seems for a channel to lock in, it needs to be above 55% strength, whereas to watch it clearly once locked in, it needs only 41% strength.

I'm able to lock in new channels one at a time without rescanning, provided there is no virtual channel already in that position.

Any ideas/tools on how to unscan a specific station (eg maybe if OMNI was to go off air while WPTZ was receivable?)

Thanks.

Hello

These digital stations are great, but my tv seemingly only allows ms to do one digital scan and if info another it wipes out the first. I have a rotor and know I can get more than the few stations it lists but I have to scan with the rotor in one direction.

I can manually add analogue stations, but not so much luck on the digital end.

Is there a workaround for this?

The tv is a sharp aquos.

Thanks!

Btw. A new tv isn't out of the question! I just want my ota!

Unfortunately ,.. It seems that most TVs with built-in tuners require a full scan, especially if that same RF channel is already in the memory. Some set-top converters have a 'add channels' auto scan function.