Artec T3A Pro NTIA CECB - Page 9

if only my Sony - Mavica MVC-FD7 Camera could hear that,
I'm amazed this ancient artifact can still spin a floppy disk.
I have to hold a magnifying glass between it and the board...

Yeah, NTSC determined the resistor was just a zero-ohm jumper,
and the caps were small RF shunts additions for the On/Off button.

did you catch my "Pinhole" question below?

You also answered another question with your Pic.
Yours shows the cutout in both LL/LS jacks facing the PCB's front.

NTSC's Pro Pic shows the cutout facing the PCB back instead.
This confirms the pin reversal between LL/LS and the Pro models.

Additionally NTSC's Pic-2 and Pic-3 clearly show
the red #1 indicator wire orientated closest to the tuner
and connecting to the trace that leads to the center power button SW1.

Additionally, even SatPro posted a Pic of a slightly different revision
of the Pro that has all the same indicators as the above examples.

It took a moment to piece that all together...
Bet you were scratchin' yer head for a moment too NTSC...

********************************************

I hope to purchase both an LS and a Pro next month for fun.
I like these little buggers.

I should point out to those that haven't followed my CECB landslide,
that I am one of the few that live in an area the Zenith DTT-900/901 just won't work.
I get steller performance fron the Channel Master CM-7000's though.

Of this round of two box purchase, the Craig is positively useless.
But I'm happy to report that unlike a half dozen others that couldn't work,
this LL model works almost as good as the the CM-7000.
Trust me, thats saying something good for this item!

The lone resistor was just a jumper. But after further examination I now see that the two capacitors, which are actually in parallel, and total about 0.1 uF, go from pin #1 (the red wire) to ground (pin 7). Ground also includes the back of the board, and the majority of the front. (Thanks WeThePeople for catching that!)

I still say they can be ignored, as long as you twist your wiring harness 5 or 6 times.

I'm near certain that the back side of that will turn out to be ground.
How else could ground get the the center power On/Off button except
through plate through holes to a grounded backplane.

I can't be certain from your pic of the whole set connected
and switch board still screwed to the top.

But the non-trace circles I see appear to be plate through's
with standard-issue quad fusible link traces to the backplane.

Check your tuner casing to the other side of those capacitors and You should find it is a ground pane for shielding.

OK, after FURTHER examination... Yep, you're right. (Just needed a bigger magnifying glass! - And to get off my butt and pull out the meter.)

Hey, It's Sunday.
Your soooo allowed to be casual.

Let me share an old joke with you.
Nothing personal meant, It's just funny (But true).

I (As example) chose a nick which means I am everyone,
yet still I am absolutely invisibly no one.

NTSC = Never Twice (The) Same Color

I see now, they filter the logic supply to the switches; one at the connector and one at the first switch the trace contacts, I suspect to prevent the trace from becoming an antenna. It looks like one cap is gray and one is brown unless that's due to the angle of the board in the pic (my thought is for broadband RF bypassing one would use a 0.1 uF and say a 0.001 uF in parallel).

0.1 uF are pretty common, littered all over most boards. If you have a schematic for some junk boards you can find them easily. For this value/app the physical size isn't important if you can get what you find to solder OK.

Ahhh, I think I know what you're talking about now, the vias (circles) with the skinny traces to the surrounding plane. That's a thermal relief patter for the solder process; a via connected solidly to a plane can heatsink too much resulting in a poor solder joint. A good example is something we called tombstoning (): CB2 would tend to flip up as one side of the cap soldered faster than the other side.

That's interesting if the LL is working well for you as they have the same tuner/decoder chipset (LG) per Wiki. BUT Wiki does show that some 900s had the Sanyo tuner. If both are LG it makes me wonder if there are some user-adjustable RF settings? (ex: sensitivity vs multipath trade-off).

Thats interesting to know and makes sense too.

I always saw them frying left and right in cheap overseas radars and sonar boards.
I always thought them to be fusible links by design as that is what they become quickly when electrons meet water or overload...

No, if the DTT-900 had the Sanyo tuner I probably would have kept it
(If late feb / early march production without the audio glitch).

Yeah, PCB designers will tend to use default patterns which might be too skinny for some circuits, gotta watch those guys. It's usually done when the completed circuit design is processed for DFM, etc. (i.e. they sneak it in on us when after we think we're done). Us RF guys don't like those at real high freqs either, the little traces become inductors.

I've seen strange stuff like you're talking about though, usually where the traces tie to connectors. Another weird one is odd shapes near connectors to make spark gaps for static, lightning, etc.

Since those capacitors seem to be getting a lot of attention, I went ahead and added them to the schematic in my original post. The two capacitors on the board were identical, and in parallel with each other. They total about 0.1uF. A small ceramic disk capacitor will do nicely.

Later...

Hey NTSC, how old is your Pro from that teardown pic? I don't remember if we determined if the latest Pros have Sanyo tuners (LL, LS, who knows? LOL).
------------------
I received my LL the other day, so far so good, Mikey likes it. After initial setup in the house (attic antenna), I hooked it up in my van with a portable analog LCD via composite connections. What a rat's nest of cable! Cig lighter in the front and aux+antenna jack in the side didn't help either (watch your step!). Worked better than I expected, received almost as good as in the house.

Anyone know anything about those conversion van luggage rack antennas? VHF? UHF? both? Directivity? (which way do I point the van?) Omni-directional? How are they constructed? Maybe I should just put the van on a turntable to figure it out.

I DID NOT start the engine with the Artec to battery (I did try one of those DC-AC inverters just for the heck of it, worked fine, no noise). Looking back at the #184 LL pic, near the DC connector, it looks like there could be two switching regulators. Look at the two sets of a shielded toroid (220), 8 pin IC, and I believe a diode and low ESR tantalum cap - common elements for these small switcher circuits. All surrounded by big caps to clean up the ripple, among other things. I suspect they go down to an intermediate voltage (parallel) or two as I see what I believe are linear regulators scattered throughout the board (the 4 pin dudes with one big thermal lead, could be power transistors/switches though). Anyhow, if someone can read the print off of one of those 8 pin ICs I might be able to determine the input voltage rating for the regulator(s). It might even run at a lower voltage, the one I helped design ran from 5 to 16 V (5 V out).

Those 8 legged chips are marked MP9141ES-77840419.

I doubt mine is one of the newer ones. The newest date code I found on the chips in my Pro was from right around Oct. 08. There's a small pict of it open in post 213. Has the Sanyo tuner and the empty pads for the missing smart antenna connector. It also has the empty pads for that odd reset switch others have mentioned (next to the IR receiver module.) Shorting them just does a soft re-boot, like turning the box off, then immediately right back on again.

The two 8-Pin surface mount IC's you speak of are
Motorola MP9141ES in standard SOIC-8 casings.

I've only a sec right now, but here is some info.

They are simple "Buck" style PWM voltage reducers IC's
The equivelant numbers I found were TD1410 and KT6141.

HERE is a similar cross equivelent TD1410 PDF datasheet.

That should get you up to speed on how they are metering
the Wall-Wart down to 3.3 and 5 volts.

You can see the two inductors they use next to each IC in pics from this thread.

They are 3.6 To 18 Volt in typically.
They "Buck" at a fair 380KHz,
and can supply about 2-Amp

Remember, these may handle up to 18-Volts in,
But other circuitry also present like on/off circuits may not!


I failed to find an exact Motorola PDF datasheet link,
just dozens of online whores that said they did (As usual...).
Happy hunting.

I will try to make time to trace out the initial power path in these LL's when gravity makes my chair the only fair option some late night soon.

Thanks. Aw shucks, well maybe someone that bought a Pro of late can check. Somehow I suspect they're still the same since no one advertises them as LL. Funny all this tuner change business; same thing with Zinwell. I didn't notice much difference for the Zinwells between Microtune and Sanyo tuners BUT one of my Sanyo versions has an RF input impedance>synthesizer losing lock problem (pic depixellates until retuned, really sucks when it does it during a recording); I'll probably try some resoldering when I get a chance (warranty? LOL).

That could be a factory reset switch, maybe they get locked up during tune (?) & test and the comm link is frozen. Throw money at the problem.

That's funny, Motorola has been out of the IC biz for yrs now. Sold off the smaller stuff to ON Semi and spun off the rest via Freescale Semi. Definitely a Mot # though, probably some Taiwanese firm bought the line.

Assuming the specs are identical, I think I see the problem. VEN is only rated to 12V which I suspect is tied directly to the supply line. The vicious circle of trying to enable a voltage regulator by a logic circuit whose power is supplied by the regulator. Can be fixed with a resistive voltage divider if it doesn't already have one (i.e. maybe they just didn't want to spend the time&money certifying it for auto use). But like you said, there could be other circuits on the input supply line to contend with, but I don't see why if this regulator is enabled by the supply line. Stranger things have happened though.

Just for grins I plugged my Zinwell 5V wall-wart into my LL, worked no problem. They should market this versatility (time&money cert again?) for use with other supplies, battery packs, etc. There's a transformer relationship though such that proportionally more input current will be required as the input voltage goes down.

Now thermal is another issue (auto) but they use two of these things for only 4.5W max, and I would think somewhat evenly distributed.

If only the government had a project that could be used to clear out old stock in cheap (+Inexpensive...) consumer electronics of some kind.

Oh wait, NTIA spec'd boxes fit the just bill fine.

Anyway, the LL will take ~15.14-VDC for a full hour without excessive heat to any components (Out of case).
That is just what a laptop brick happened to put out that also had the correct plug on it. It varied a little under 1/10 of a volt which is fair for the really light load the LL is.

I will still trace out the power circuit later, but that is the answer people need now concerning camping & power outage Marine/Auto/RV/Etc. use.

If most everything is supplied by those switching regulators then I wouldn't expect anything to get hotter; in fact the regulator IC itself appears to get slightly more efficient with higher input voltage. My concern is the breakdown voltage of the enable circuit (excluding anything else tied directly to the input supply line) but that's good that it took the 15V; may degrade reliability though.

I see the TD1410 datasheet shows a built in thermal shutdown function. That's good if the rest of the Artec can handle higher ambient temperature before the regulator shuts everything down (if it ever does - low load current). It is a pretty low power usage CECB. I find it odd that they used two switching regulators when each one can supply 2A (cost/components/space).

If you appreciate that irony,
then you'd like one of the cartoons I remember.

Simple one screen cartoon.

A man using an old fashioned trigger operated soldering gun,
soldering a new 120-VAC wall plug on a device,
the soldering gun itself...

In a 12v cig lighter plug for the Artec Pro and LL what amp fuse should I use?

Refering to my T3AP-LL teardown you'll see it consumes a little under a quarter of an amp at 12-V.
But the capacitors that must charge upon connection would probably blow a fuse that small.

Go with a one ampere fuse.
Anything catastrophic in nature would surely pop that.

You can try 250-Milliamp (1/4-Amp),
and 500-Milliamp (1/2-Amp) fuses
nd let us know (if you have a full draw of them to waste).

Ouch! Dog chasing its tail and got a bite.

FWIW - I just got a pair of Artec T3AP-LL's at Meritline for a total of $2.99 after rebates.

Link:

http://www.meritline.com/artec-full-...--p-29296.aspx

Sorry to hear you lost $2.99, I just clinked on that link and it showed to be $0 after rebates.

OK, so there's a TV Guide (TVGOS?) version of this box; would this provide an exceptional EPG if one has the required "TV Guide on screen/Guide plus+ Product"?

Also, I have a VCR Plus+ VCR; is this the required product?

Thanks in advance!

Other: My van>luggage rack antenna-connected LL received pretty good over the holiday weekend in a valley in the hill country ~25 miles north of Austin, TX; the only catch is the transmitter is only about 10 miles away, being they like to place those out in the sticks around these parts. My biggest problem was I had to keep adjusting the brightness on the portable LCD TV due to self-heating in an already warm environment.

The LL would glitch when tapped or moved around bumpily (hard to avoid in the van with that rat's nest of wires). I suspect due to a mechanical/piezo effect on the VCO's crystal oscillator, a common problem with consumer receivers not designed to be moved around.

No, the VCR Plus+ VCR is not the required product. That's when you only have to enter a code to setup the VCR to record, correct? If you have a TV or other device that used to receive TV Guide OTA then the TVGOS version of the converter box would allow you to receive it.

Understanding TV Guide On Screen
http://www.crutchfield.com/S-7eAuKh7...rs_tvgos2.html

http://www.artectv.com/ehtm/products/t3aprt.htm "Works with TV Guide on screen/Guide plus+ Product"

Owner reviews: http://www.meritline.com/artec-t3apr...--p-34159.aspx

It comes down to that if you didn't used to receive TV Guide OTA then you won't receive it even if you bought the special Artec converter box.

I'm not that familiar with this VCR as my neighbor gave it to me, but it doesn't work well so I set it aside. But after reviewing your info I see what you mean. The "Plus+" threw me off as Artec puts that in their TVG info (I noticed it's not described the same way in the Crutchfield article, which also has a "VCR Plus+" hyperlink at the end). I now suspect a product should have the TV Guide/On Screen logo on it.

Thanks again and you saved me bothering with it. Although it might be worth picking one up if I could get it cheaper in the event I stumbled across a TVGOS recorder. The Crutchfield article claims 8 days of data (assuming the broadcasters and/or CECB supply it all).

A quick review of my initial look at the ArtecT3AP-LL which I received today from freetvsignal, apparently at the end of their "free" offer for this model.

As I posted, I waited until last minute to use my last coupon not realizing that I could not find anything but two products at stores and that most online sites were out of boxes.

My quick read of this product led me to believe that it included features I was looking for most - an extended EPG and a decent tuner.

When I looked at the exterior of the box, I was surprised that there was only a power on/off button. I had thought by looking at a picture of the box from the ftvsig site that a channel selector button(s) surrounded the inner power button. Oh well.

My first reaction to the box itself is that it was a nice small size (no way to miss that large power button in the dark!!) and that the remote buttons were tiny like the size of those on my Zinwell remote.

But what surprised me and pleased me were the number of "dedicated" buttons on the remote to frequently used functions like accessing the EPG and sleep operations. There is also a "freeze" button which looks interesting.

The manual looks to present information fairly straight forwardly.

I was concerned at first when I saw a picture of the display of the "now and next" content for the EPG and was relieved to learn that by pressing the up and down arrows, that an extended listing of programs can be accessed.

It may have been Floydage or another poster who mentioned that this box offers some features that other boxes don't have. I wonder what features Artec users find most useful and/or interesting.

I like what I see so far. When I first wrote down a list of CECBs to consider at the beginning of the digital transition last year, this was one box I had considered and then dismissed due to the appearance of the big power button on the top of the box (and no inclusion of a channel selector) and found myself pursuing the Insignia, Zinwell, and Pal Plus. And prior to the increased signal of stations, I picked up a Channel Master upon being reminded repeatedly that for strength of reception, this box was among the best.

Looks like the Artec will be a welcome addition to my collection.

Every box has some negatives. Anything to be forewarned about? (I have found only one with the Insignia, not including the one box I returned due to a faulty antenna jack)

Mr100watt can you please give a full picture quality comparison between all of your CECB's?

I have Zenith DTT901, Artec T3AP-LL, Artec T3AP-LS, Apex DT502, Inet SSR1921 and rate them in that order.

Zenith DTT901 has a slightly softer picture than the Artec but causes less eyestrain than the other boxes. The Zenith has slightly more sensitive tuning than the Artec T3AP-LL.

Artec T3AP-LL picture appears to be slightly brighter and more vivid than the Zenith but slightly grainer.

Artec T3AP-LS the RF output picture has diagonal background pattern on some stations but AV output is the same as the T3AP-LL box.

Apex DT502 picture is grainy and darker than the Zenith and Artec boxes using RF and AV cables and I do not have an S-video TV to test that output. Tuning only picks up half as many stations as the Zenith DTT901 box.

Inet SSR1921 picture is worse than the Apex but the tuning is more sensitive than the Apex.
The worst thing about the Inet SSR1921 is when you change the aspect ratio to fill the screen the picture becomes even grainer and completely not watch able. When the aspect ratio is changed on the Zenith and Artec boxes I can see no difference in picture quality.