The DTV transition: The low-down on analog pass-through

Most TV stations must stop broadcasting analog signals on February 17, 2009, but some stations don't have to switch completely to digital broadcasts. Low-power TV stations, TV translator stations, and so-called Class A stations can continue broadcasting analog TV signals well after the deadline. If you're in an area served by such a station, you'll want a DTV converter box that can handle both digital and analog signals. Of course, if you're not able to receive any digital stations, there's no rush to buy any converter box, and we anticipate there being a greater assortment of boxes with analog pass-through in the not-too-distant future.

Low-power TV was created in the early 1980s to provide locally oriented or specialized programming to smaller rural towns or small communities within urban areas. TV translator stations boost and re-broadcast the signals of full-power stations to communities that can't receive them either because they're too far away, or because mountains or uneven terrain inhibit reception. Class A stations are a class of low-power stations that are required to air a certain amount of locally produced programming each week.

The vast majority of TV broadcasts are from full-power stations that will switch to digital, but nearly 7,000 low-power and translator stations provide free over-the-air TV programming to viewers. Although they will one day, too, have to make the switch to digital, currently there's no firm timetable for that transition. Therefore, if you're in a market currently being served by such a station, we recommend you get a DTV converter box with "analog pass-though" capability. These boxes allow analog TV signals to pass through the box without being converted to digital so the TV's analog tuner can receive and display them. We recently ran preliminary tests on one of the early pass-through models, the Philco TB100HH9. We'll be posting that review here shortly.

There are a few ways to determine if you're being served by one of these types of stations. Most low-power stations typically have call letters that end in –LP (such as WAOH-LP); some have five characters starting with the letters K or W, followed by two numbers and two additional letters (W35AX, for example). A translator station uses a similar designation, with its channel number in the middle of its call letters. You're viewing a translator station if you're watching a full-power station but have to tune to another channel to watch it. And Class A stations can typically be identified by the use of a –CA suffix. The National Telecommunications and Information Administration (NTIA), the agency administering the DTV converter box coupon program, has online a complete list of low-power and translator stations.

According to the NTIA, there are currently six approved converter boxes with analog pass-through capability. They are:

• Digital Stream DX8700
• Digital Stream DSP7700T
• EchoStar TR-40
• Magnavox TB-100MG9
• Philco TB100HH9 (seen at right)
• Philco TB150HH9

The NTIA maintains a list of all approved converter boxes online. (Models with analog pass-through have an asterisk next to them. We've previously previewed three DTV converter boxes (without analog pass-through): the Magnavox TB100MW9, Insignia NS-DXA1, and Zenith DTT900 (seen above, left). For more information on what else you need for digital TV on your analog set, see our previous post, "How to use a converter box & antenna to get DTV."

If you've already purchased a DTV converter that doesn't have analog pass-through, you're not completely out of luck. You still may be able to get analog signals to your TV by using an antenna switch or 2-way splitter. Use a splitter if your TV has separate audio/video inputs. Just connect the antenna feed to the splitter, and run one cable from the splitter to the RF input on the TV and another from the splitter to the digital converter's RF input. Connect the converter's A/V output to the TV's A/V input.* You can watch the analog programs by changing channels using the TV's tuner. When you want to watch a digital channel, just switch to the video input.

For TVs that only have an antenna input connector (no separate video inputs), you'll need both an RF antenna splitter and an antenna A/B switch. The splitter should be connected between the antenna and converter box, with one cable connected to the DTV converter box's RF antenna input, and the other going to one of the inputs on the 2-way A/B switch (effectively bypassing the converter). Then run a cable from the converter box's RF output to the second input on the A/B switch. The A/B box's single output is then connected directly to the TV's RF (cable) antenna input. When the A/B switch is on the "digital" (A) side so it's receiving the converter box's signal, tune your TV to channel 3 or 4 to watch digital programs. When you click the switch to the "analog" (B) setting, you'll be able to view any available analog programs by changing channels on the TV. The downside is that you'll have to manually switch between the two inputs on the A/B switch every time you want to switch from an analog channel to a digital one.**

—James K. Willcox

* April 9, 2008 UPDATE: In a previous version of this post, we had inadvertently misplaced a line of text describing the correct procedure for using a converter box with analog pass through.—Ed.

** April 11, 2008 UPDATE: Additional information was added to help clarify how to use an A/B switch with a converter box.—Ed.
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Comments

[Lynn M.]

I couldn't get any analog stations with my box hooked to my TV. The directions that came with my Tivax STB-T8 didn't say anything about how to make the analog pass though work. Fortunately, someone on the AVS Forum helped me out, and for the sake of any other dummies out there, this is the missing piece: In addition to fastening the coax antenna cable to RF input on the box, and fastening the red/yellow/white composite A/V cable from the TV to the box, it is also necessary to connect a piece of coax cable from RF output on the box to the RF input on the TV. Place the box on standby and surf channels with the TV remote or TV channel buttons. Tivax provided both the A/V cable and the short piece of coax cable.

I sure wish Tivax had mentioned that in their instructions.

[Lynn M.]

I just hooked up a Tivax STB-T8 with analog pass-through. I get one digital channel. With the box hooked up, I can't get any of the 6 analog stations I was getting. The directions don't tell you how to get analog pass-through and Tivax doesn't have a number or website to ask. How does one get analog stations on an analog pass-through DTV?

[everett whitney]

TO: Kim-02 Oct- " A Button for Pass-thru ? "

That's essentially what happens anyway ... the TV Remote must be used in order to "auto-program" & search for any existing analog channels still actively broadcasting - today or in a year.

[Kim]

With an analog pass-through converter, can it be operated in non-pass-through mode? i.e. something like press a button on converter remote to deactivate pass-through and I use my regular TV remote to flip channels?

[everett whitney]

TO: ROB - 28 Sept - " Any Chance these are Not China...?"

Sadly, Not a single one!

The very minimum specifications, bid & build by the least of the makers! Do note that none of the top Tier HDTV makers bothered to participate.

Between UHF band will need constant adjusting of any indoor antenna, the expense of an appropriate new outside UHF antenna system, the added problems of obtaining reliable, all-weather UHF band reception, federal coupon Converters will be unsatisfactory for many.

[ROB]

Any chance any of these are not made in china?

[Denice Rhodes]

Even with great instructions like yours, some people will still be left behind once the switch is made to digital tv.

Our non-profit, the Urban Progressive Foundation has been actively working with seniors and other groups to provide straight, clear and understandable information to help them through the transition.

Later this week, I will be traveling to Wilmington, North Carolina, where the first full blown transition test-run will commence (if the hurricane doesn't alter plans). If you can't make the trip, allow me to be your eyes and ears. Visit my blog http://digitaldynamo.blogspot.com/ and website www.transition2DTV.com to for more information.

[Mike]

Canada won't require digital broadcast of its channels until 2011. That's why those of us in a border city (like Detroit) need analog pass through but I haven't found 1 converter in stock anywhere around me. I only have 16 more days and I just started rechecking the local stores. This 90 day restriction, with not all converters being available for purchase, is among the stupidest things our government has done. Why are they making it difficult to get the converters?

At worst, I'll buy a non-pass through converter and hopefully sell it to someone else who gets their coupon later. I would've waited to order my coupons if I had known I wouldn't be able to purchase what I needed.

[Joseph Held]

I have a DVD recorder and the convertor box I purchased did not tell you how to hook it up to the other components. I think I've figured it out, but my Panasonic DVD recoreder won't record the digital stations. I have to split my aerial so that the recorder can only record analog. Does this mean that my DVD recorder will be obsolete come February. Also,I get more stations on the digital, but there's no comprehensive TV guide for the programs. Also, I lost a PBS station that I can only see on Analog. I'm not particularly happy about this situation. Any suggestions? I've tried contacting the manufacturer of the convertor box for help, DIgital Stream, their phone is always busy and the website they direct you to is TOTALLTY USELESS! Thanks for listening!

[Jerry N. Marilyn]

I have 2 Magnavox DTV converters. Took hours to make them work w. our old TV sets. Now trying to use them. But set up gave us 27 digital channels each with a number like 3.1 thru 3.4, 8.1 thru 3, 13.2, 16.1&2, etc. thru 62.1&2. Is there some TV guide to help know what to tune in to get the channel we used to use.

I have never liked TV since 1947 but my wife wants to watch channels she likes and I drive her nuts when I used to switch any time ads come on. I will never buy cable and only have a land line in MI and no phone when in FL for 4 mos.

How do I find a TV guide that converts these #s into letters of the channels into letters we understand in Clearwater FL and Bloomfield MI? PBS is the only thing I like about TV. Hate ads.

[Elle Bowen]

I live in New York City and cannot seem to find anyplace that sells the digital converter with analog pass through. I requested and received my $40 discount card but fear I will not find a place to buy one in the time I have to purchase.

How can I find where to purchase these pass-through converters?

[MJ SNEAD]

Just bought and connected a Magnavox TB100MW9 converter box to my set. Even though reception on the low signal stations are better. I lost 3 stations; of which 1 I don't really care about, and 1 I really do because its all the ABC shows. I origninally had 8 stations. . .I did not gain any stations, as other people have stated in their comments; I think thats all hype, unless their counting all the weather station & Infomercial substations of a TV channel. (I've already deleted the Spanish station and its two substations which I don't count either). Also with the TB100MW9, I do not like the fact that it is automatically set to turn off in 4hrs(as a power saver), since I record several shows at night while I'm at work;(so what? I have a show set to record at 10p.m. - power on the the STB @ 2p.m. and by 6p.m. it turns itself off...JUST GREAT). I have another coupon, which I think I will be buying an analog/digital passthru converter box. I'm hoping there is one with no powersaver - I can set the sleep time on the TV itself for that thank-you very much.

[NTV/NAT Group, Ltd.]

What's the point of low-power TV stations in the U.S. anyway? I know you gave the definition in the story, but here in Canada we don't have L-P stations. If it's so vital to the community, you stick it on the local Commmunity Channel (what Americans call Cable Access).

[Paul Eng]

To Don:

You are absolutely correct in that we inadvertently left out a line of text. We've posted a correction to address this unintended mistake.

Thanks for pointing that out to us.

—Paul Eng, Web Sr. Editor, Electronics

[Don]

There is a missing line in your description of analog pass-thru. It should read "Just connect the antenna feed to the splitter, and run one cable from the splitter to the RF input on the TV and another from the splitter to the Digital Converter's RF input. Connect the Converter's A/V output to your TV's A/V input. The Converter may provide A/V cables"