Samsung DTB-H260F ATSC tuner - Page 8

They talk about it in this thread,
http://www.avsforum.com/avs-vb/showthread.php?p=7029314

I bought a Samsung DTB-H260F tuner today. I found that it was unable to consistently lock any new stations. I found the results very close to those of my Dishnetwork 622. I used dual output amplifier with the two boxes side by side. One station that was right on the fringe pixelized only slightly more with the 622. I am returning the Samsung tomorrow. I don't think this box is nearly as good as reviewed. I am disappointed. I was hoping for something revolutionary.

My current setup is as follows:

I am about 55 miles from Washington DC and about 70 miles from Baltimore with mountains between me and both cities. Since I refuse to put my antenna on the roof, for a variety of reasons, I have ended up with a CM4228A in the attic on a rotator along with a CM777 preamp. (I also currently have an old Yagi antenna feeding VHF into the preamp for NTSC reception.) I use a Hughes HIRD-E86 STB for OTA reception.

This setup works amazingly well, considering the distance and the attic installation! I can typically receive about 10 different digital stations with about 20 channels of digital programming, plus about 20 more NTSC channels.

However, I seem to suffer from the following ATSC reception woes:
1) While three stations in Washington, DC come in clearly, three others are only marginal, working sometimes and not other times. If I buy a new HDTV receiver, it *must* have outstanding sensitivity, which basically means an industry-leading tuner. Based on posts by goldenrod and this one by Hokie (Va Tech?) Jim have convinced me that the Samsung DTB-H260F does not have an outstanding tuner.
2) The station which is closest to me (~25 miles) often suffers from terrible multipath distortion (though it occasionally works great??). It seems that the Samsung DTB-H260F would definitely help with reception of this channel.
3) I receive an NTSC signal off the back of my antenna at the same frequency as one of the ATSC channels I'm struggling to receive from Washington. I doubt any tuner can help to receive this signal. I'll either have to fiddle with my antenna or simply wait until NTSC is turned off in 2009.
4) My current tuner does not have the "add" feature mentioned earlier that can be used when scanning for channels. That sounds like a *great* feature for anyone using a rotator or multiple, switched antennas!! Unfortunately, the Samsung DTB-H260F does not help me there, either.
5) My current tuner only reports "Local programming" in the program guide (no actual programming). The detailed program guide on the Samsung DTB-H260F sounds great! Definitely a selling feature! (I would be using either component video or HDMI connections, so this *would* work for me.)
6) Another important consideration before the NTSC cutoff is that NTSC can be used when ATSC does not cut it. As such, I will say that any receiver I purchase before 2009 needs to also have an NTSC receiver.

If I decide that 3) above is not a receiver issue, I would conclude that the Samsung only has 2 of the 5 features I would require before I would replace my current tuner. Unfortunately, not enough...

Thanks to all for this thread, as it has helped me to refine my HDTV STB shopping list and to understand how the new Samsung stacks up (without actually purchasing one).

Thoughts?

Reg

What antenna are you using? What type antenna does http://www.antennaweb.org say you need? Enter your complete address at antennaweb and post the results here.

RegGuheert:
It will add a channel if you input it manually and if it receives it, then it will be in your line up.

Microtune's Double Conversion Tuner chip discussion began in this post:
http://www.avsforum.com/avs-vb/showt...ne#post7209568
Read down for couple days of discussion....

Microtune website is here:
http://hraunfoss.fcc.gov/edocs_publi...C-05-199A1.pdf
MT2131 Spec sheet and their "benchmark comparison report" is here:
http://www.microtune.com/products/pd...1_tuner_ic.pdf
http://www.microtune.com/products/pd...benchmarks.pdf

I provided a link to two technical articles written by John Norsworth of Microtune here:
http://www.freelists.org/archives/op.../msg00028.html
He presents the double conversion tuner being used WITHOUT an RF Tuned Bandbass Filter on the input--
which of course results in better Sensitivity (e.g. Noise Figure) by eliminating the loss in an RF inductor and Varactor Diode
(voltage variable capacitor for tuning input RF filter).....and makes for a much more compact design that could fit into a USB Stick.

However, the RF Tuned Bandpass Filter (typical bandwidth of 10-20 MHz) on the input of a single conversion tuner
plays a very important role in suppressing strong stations so that you can receive a desired weak signal.
Hence, the primary use for a double conversion tuner would be on a cable system where all the signals are roughly
the same strength, so the tuner doesn't have to try to receive a weak signal among many other strong signals.

Microtune cites improved performance for adjacent channel performance (D/U ratios), which would be
nearly unaffected with or without an input RF Bandpass Filter.
What has NOT yet been revealed is how much sensitivity is lost from overload from ALL the other channels
across the entire band if an input RF Bandpass Filter is not used....hopefully, an OTA tuner would not forgo the input RF Bandpass filter...

====================================================
FYI: The FCC sponsored a series of tests on various OTA STBs and HDTVs (sshhh!!! no names!!!!):
http://hraunfoss.fcc.gov/edocs_publi...C-05-199A1.pdf
See page 31 for Sensitivity and page 34 for ability to decode the A/74 Field Ensembles.

Where can I purchase the DTB-H260F online? I have been searching for quite sometime now w/ no luck.

CircuitCity is one such place.

B&H Photo (very reliable) has it on order.

Go to Best Buy, if they don't have it, have them check the other local store inventories. If it is farther than you want to drive have them transfer one up to their store. You will have to prepay, but it is reserved for you.

I did it that way and got mine in 3 days.

The usual suspects:

Amazon (lowest price AFAIK, free ground shipping, not in stock)
One Call (will price match but charges for 3-day shipping, also not in stock)

and the others mentioned above.

HTH

You sure can not find one here in Raleigh, NC at either Best Buy or Circuit City. All the salesmen I talked to acted clueless as to what a ATSC STB even was.

Basically I got the why would you buy a STB when most tv's have it built in?

-DonB2

Two Best Buys in our area have them in stock.

Thanks for your help guys... I picked one up at BestBuy in Burbank, CA (Store #137) during lunch. Got it for $158.39+tax with a 12% off coupon from ebay. They still have one left, now I just need a good antenna...

I purchased mine last week from One Call and received it in 3 days. Shipping was free via FedEx. I recommend you call to order vs internet as I had problems with their website but was treated great via phone. It arrived with lots of extra packing wrapped inside another box - no damage.
Pete

Currently, 1 C*A*L*L doesn't have them in stock.

It appears that CC has these back in stock online.

http://www.circuitcity.com/ccd/howTo...oreStores=true

Yes, I just bought one!

Does this tuner map channels from the real channel to their logical channel? For example, real channel 48.1 is known to viewers as channel 5.1. Which channel number would I use after setup to tune in that channel?

It maps to the virtual channel number the station chooses, which is usually their old analog channel number.

I don't think it's "logical" though, but you may differ.

After analog is shut down, I think they should be forced to use the actual channel number they're broadcasting on.

Thanks!

I interpret your response as covering OTA DTV channel handling.

I agree that everything would be simpler if they just used the real channel numbers (actual frequency assignments) instead of mapping, until you get to cable equivalents and yet another set of channel numbers.

I forgot to ask if the DTB-H260F handles QAM cable real channels and "logical" channel mappings the same way as for OTA channels.

My sister in law has the older Samsung 451 model and she uses it for HD reception from Comcast cable. The 451 does not map from a cable channel (e.g., 84.2) to the logical channel (e.g., 5.1) that is "viewer-friendly." So she has to keep a listing of the HD cable channel numbers handy to find what she is looking for.

Comcast periodically moves their real QAM channel assignments around, confusing the humans even more, and requiring a new scan or manual manipulation to get the desired channels and drop the unwanted channels.

I am aware of ATSC/QAM tuner-equipped HDTVs that map channels numbers for the QAM scenario. Hitachi is one example that does so.

I believe that is a function of the broadcaster. The virtual channel is mapped according to information broadcast in the PSIP info. It's Comcast who is mapping to 84.2, not the STB.

The FCC and the NAB rightfully pushed for mapping for many reasons.

First, it was felt, and rightfully so, that the majority of the public - not readers of this
Forum - would not easily adapt to the fact that Channel 56.1 is in reality the digital version of Channel 2.

The biggest reason for mapping is that television stations expend huge amounts of dollars and time to promote themselves using their analogue channel allocations, not their call letters.

This came from experience in England where no one cared about a channel allocation -
the operative thing was the program service. For example, BBC 1 in London might have been transmitted on UHF Channel 37, but the customer didn't care and didn't know.
The only one who was involved on the receiving end was the person selling you an antenna.

All of the BB employees that I've encountered in all of their stores that I've ever been in "act" that way.

They're trying to get you to either:

a.) buy a new TV from them, or

b.) subscribe to Direct or Comcast through them.

They are the most dishonest, least trustworthy salespeople as a whole that I've ever dealt with at any electronics store. They must train them that way, because they all try to pull the same BS (in my experience).

Correct.

The mapping comes from the source. If OTA, the tuner gets the virtual channel info from the broadcast signal. On cable, the virtual channel numbers come from the cableco. And if the cable channel numbers are not the same as OTA, or if they intermittently change, that's the cableco's fault, not the tuner. The tuner is only displaying what it's receiving.

I assumed the OP was referring to OTA broadcasts, since I saw no mention of cable in the post.

I understand PSIP data enough to realize that the broadcaster specifies the "map to" channel number for OTA. I have one OTA HD receiver that uses that if I set the option correctly.

On the cable/QAM side, I don't know if the channel mapping from the broadcaster makes the trip succesfully all the way to the QAM tuner. I have seen two examples from the same Comcast Cable head end site:

1. A Samsung SIRT-451 ATSC/QAM tuner that does not display the "map to" channels numbers, and there is no apparent user option setting to make it happen;

2. A Hitachi cable-card-ready HDTV without a cabel card, receiving QAM channels and mapping most of them (but not all) to the "map to" channels from the broadcasters.

I am left to conclude that the 451 box will not support channel mapping, even if it is available from the cable provider.

I am asking whether the 260 box supports channel mapping from cable QAM sources or not.

Sorry if I was not clear in my earlier posts. Thanks for the responses.

It doesn't. The cableco must remap them correctly when re-encoding them to QAM or they will just be obscure numbers.

A local cableco in our area correctly remaps just one local HD channel (CBS). All the rest are off the wall numbers requiring a pen & paper list.

So, assuming the cable company has met their obligation to provide the mapping information in the data stream, will the Samsung DTB-H260F use that data and perform the mapping so the viewer sees the familiar channel numbers?

I have one in Raleigh, contemplating returning it. While it appears to pick up OTA just fine, it does *not* appear to pick up the unencrypted QAM/256 that time warner cable is putting out. I verified I could get the channels by lugging my PC with a cheapo fustionHDTV card in it down there and doing a channel scan and getting all the channels.

Switching between HRC/IRC/STD made no difference. Quite disappointing, really, because all I wanted was the unencrypted stuff over cable.

Does this unit supporting tuning subchannels without the "Up/Down Channel" buttons? My local weather sub-channel is 25.3. Can I type 2-5-3 on the remote and have it tune in to that channel? I'd really like an STB that can tune subchannels so my ReplayTV can tune subchannels via an IR blaster. Thanks!