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Channel Master CM-7000 Digital to Analog Converter - Page 3

post #61 of 1459
3/27/08 at 6:54am
dingo99, you mentioned not voiding the warranty. What is the warranty?
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post #62 of 1459
3/27/08 at 8:30am
Quote:
Originally Posted by kgj67 View Post

dingo99, you mentioned not voiding the warranty. What is the warranty?

Actually it was DJ99 that bought the box, not me. I missed out on the $60 pricing at Fry's, so I was just studying the photos. Good question, though - maybe DJ99 can fill us in?

Also, another question for DJ99: You mentioned the Fry's in Illinois accepted the coupon. When you check your coupon status at https://www.dtv2009.gov/CheckStatus.aspx does it indicate that your coupon has been redeemed?
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post #63 of 1459
3/27/08 at 11:12am
Sorry guys, don't waste your time with further research on the digital audio output...I called CM's tech support and spoke to a very friendly and informative guy who apologized and told me that they were forced to remove this feature so that it could be coupon eligible. He said that he himself wanted to use it at his house, but couldn't due to this fact. I then asked him if he was really covering for the company and perhaps it was really hooked up and he sincerely told me that he wished that was the case but is not.
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post #64 of 1459
3/27/08 at 12:05pm
So, did the CM support guy say how we could hook-it back up?
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post #65 of 1459
3/27/08 at 1:45pm
As far as how to hook it back up, he did not give any information. He claimed that to his knowledge the module had been removed. I was really hoping that it would be hooked up, very disappointed.

I recently purchased the RS Digital Stream, WM Magnavox, BB Insignia, and the Zenith DTT900 for comparison. If you are willing to live without S-Video and Dig. Audio output, the Digital Stream reigns supreme. Seems to have a very nice, sensitive tuner, quick channel changing, excellent channel-at-a-time program guide (up to approx. 8 hours in advance with scrollable program descriptions), great remote control with fast acting volume control (way faster than the Zenith), nice menu graphics, and an overall case size that is only about half the size of the competition.

Of the four I have tested, the Magnavox is the worst, hands down.
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post #66 of 1459
3/27/08 at 3:05pm
Quote:
Originally Posted by dingo99 View Post

Actually it was DJ99 that bought the box, not me. I missed out on the $60 pricing at Fry's, so I was just studying the photos. Good question, though - maybe DJ99 can fill us in?
Also, another question for DJ99: You mentioned the Fry's in Illinois accepted the coupon. When you check your coupon status at https://www.dtv2009.gov/CheckStatus.aspx does it indicate that your coupon has been redeemed?

Actually, I just made an assumption that it came with some kind of warranty. Checking the manual seems to make no mention of how long it it. I will e-mail their support to see what they have to say.

After doing a status, it does NOT seem to have been redeemed so far.
I have my box, I'm not real worried about when (or if) Fry's ever redeems it.

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post #67 of 1459
3/27/08 at 6:03pm
Quote:
Originally Posted by av_geek_97 View Post

As far as how to hook it back up, he did not give any information. He claimed that to his knowledge the module had been removed. I was really hoping that it would be hooked up, very disappointed.

I recently purchased the RS Digital Stream, WM Magnavox, BB Insignia, and the Zenith DTT900 for comparison. If you are willing to live without S-Video and Dig. Audio output, the Digital Stream reigns supreme. Seems to have a very nice, sensitive tuner, quick channel changing, excellent channel-at-a-time program guide (up to approx. 8 hours in advance with scrollable program descriptions), great remote control with fast acting volume control (way faster than the Zenith), nice menu graphics, and an overall case size that is only about half the size of the competition.

Of the four I have tested, the Magnavox is the worst, hands down.

Someone earlier reported that the Digital Stream was cutting off the bottom 10 lines of the video compared to the Zenith. Can you confirm or refute this on your units?

Thanks
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post #68 of 1459
3/27/08 at 6:31pm
I cannot confirm that other person's comment concerning the bottom 10 lines of video being cut off from the Digital Stream with certainty, but I was also only testing the composite video output on each unit. I never even hooked up the RF output because I knew for sure I would not be using it regardless of which unit I ended up with. My TV is a 27" Sony Wega and I do not recall missing any lines at the bottom of the screen while testing any of the units.

Hopefully this helps...
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post #69 of 1459
3/27/08 at 6:44pm
Quote:
Originally Posted by av_geek_97 View Post

I cannot confirm that other person's comment concerning the bottom 10 lines of video being cut off from the Digital Stream with certainty, but I was also only testing the composite video output on each unit. I never even hooked up the RF output because I knew for sure I would not be using it regardless of which unit I ended up with. My TV is a 27" Sony Wega and I do not recall missing any lines at the bottom of the screen while testing any of the units.

Hopefully this helps...

Thanks,
Arnold
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post #70 of 1459
3/27/08 at 7:58pm
Quote:
Originally Posted by av_geek_97 View Post

Sorry guys, don't waste your time with further research on the digital audio output...I called CM's tech support and spoke to a very friendly and informative guy who apologized and told me that they were forced to remove this feature so that it could be coupon eligible. He said that he himself wanted to use it at his house, but couldn't due to this fact. I then asked him if he was really covering for the company and perhaps it was really hooked up and he sincerely told me that he wished that was the case but is not.

As Ronald Reagan once paraphrased:
"doveryai, no proveryai":
http://en.wikipedia.org/wiki/Trust,_but_Verify

Wouldn't be the first time a company had to make superficial PAPER changes
to keep the feds happy....when reality was somewhat different....
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post #71 of 1459
3/28/08 at 5:02am
Yes, holl_ands, I hope you are correct about it being "paper" changes. (Ron) the guy I talked to on the phone sounded as if he knew exactly what I was getting at when asking him about the dig. audio output being "hooked up" but "not" hooked up, but he still seemed certain it was not going to work. If someone does get it figured out, though, please let us all know because I would buy this unit it if it did.
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post #72 of 1459
3/28/08 at 5:52am
Quote:
Originally Posted by av_geek_97 View Post

As far as how to hook it back up, he did not give any information. He claimed that to his knowledge the module had been removed. I was really hoping that it would be hooked up, very disappointed.

I recently purchased the RS Digital Stream, WM Magnavox, BB Insignia, and the Zenith DTT900 for comparison. If you are willing to live without S-Video and Dig. Audio output, the Digital Stream reigns supreme. Seems to have a very nice, sensitive tuner, quick channel changing, excellent channel-at-a-time program guide (up to approx. 8 hours in advance with scrollable program descriptions), great remote control with fast acting volume control (way faster than the Zenith), nice menu graphics, and an overall case size that is only about half the size of the competition.

Of the four I have tested, the Magnavox is the worst, hands down.

Hi Geek.

Which Digital Stream did you test? DSP7700T, DSP7500T or the DTX9900.
Like the rest of us, am trying to figure out which boxes will be the best bet
for what I want. I won't even get my coupons until end of May.. Thanks

Dave E
NLRock AR
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post #73 of 1459
3/28/08 at 7:47am
Quote:
Originally Posted by DJ99 View Post

Actually, I just made an assumption that it came with some kind of warranty. Checking the manual seems to make no mention of how long it it. I will e-mail their support to see what they have to say.

Received a polite e-mail from C/M customer support indicating the warranty is 90 days, parts & labor. Will be on my own before analog x-missions are even gone.
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post #74 of 1459
3/28/08 at 11:06am
Hello Whodart...

I apologize for not specifiying in my earlier post. I was testing the Digital Stream DTX-9900. Really a very nice unit all around. (This model is the only Digital Stream available in my area).
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post #75 of 1459
3/28/08 at 1:28pm
It looks like the digital audio output could be re-enabled by adding a few transistor buffers, and some resistors and capacitors. Some time, SMT work, and a scope is all one needs it appears
I like non-features like this!

Unfortunately from the sound of it, it won't ouput anamorphic widescreen, so it's off the list.
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post #76 of 1459
3/28/08 at 1:41pm
Quote:
Originally Posted by DJ99 View Post

Received a polite e-mail from C/M customer support indicating the warranty is 90 days, parts & labor. Will be on my own before analog x-missions are even gone.

That may be the same warranty that most of the CECBs will have. Some of us can buy the CECB with a credit card that doubles the warranty, though.
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post #77 of 1459
3/28/08 at 2:01pm
Fry's has the CM-7000 on sale again, so I went and picked one up. See attached for a closeup view of the digital output circuit.

Missing are 4 resistors, 3 capacitors, and 2 transistors. Using a DMM, I measured +1.65V @ RA7, +5V @ RD60, and +5V @ CD28/QD9. Any theories what the missing component values should be?

@drlava, actually it does support anamorphic widescreen. Simply hit the "Wide" button on the remote to select the "Full" picture setting.
LL
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post #78 of 1459
3/28/08 at 2:02pm
Quote:
Originally Posted by DJ99 View Post

5.When you press the Sub-title (CC)key on the remote, does it simply toggle CC on and off or does it go into a menu with all the CC options?

Subtitle scrolls through all CC options one at a time (including off).

Due to the way that digital closed captions are inserted by CECBs into the picture, it's been thought that digital closed captions will look a lot sharper and cleaner using S-video than composite. (Using RF or composite, there can be a fuzzy appearance for thin caption fonts.)

Could you check whether the S-video makes a significant difference in the appearance of the digital closed captions, and take photos?

So far, you're the only person I know with a CECB that has S-video who can check this out. (I set up a thread on evaluating CECBs for users of captioning elsewhere on this form, and it would be really nice to know whether S-video will make a difference.)

We don't have any Fry's Electronics stores out east or near me, otherwise I'd pick up a Channel Master CECB myself.
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post #79 of 1459
3/28/08 at 2:32pm
Quote:
Originally Posted by dingo99 View Post

Fry's has the CM-7000 on sale again, so I went and picked one up. See attached for a closeup view of the digital output circuit.

Missing are 4 resistors, 3 capacitors, and 2 transistors. Using a DMM, I measured +1.65V @ RA7, +5V @ RD60, and +5V @ CD28/QD9. Any theories what the missing component values should be?

@drlava, actually it does support anamorphic widescreen. Simply hit the "Wide" button on the remote to select the "Full" picture setting.

Excellent info!
Here's a quick visual analysis:

The 1.65V is the rms voltage of the 3.3V biphase manchester encoded data coming from the chip. This goes to the amp/buffer PNP transistor QD10 whose emitter (and base of QD9) is biased by RD60. QD9 may be a NPN transistor with a buffer cap on its collector (CD28). Its output goes to impedance matching/filter network RD61, 62, and CD29, and is finally AC coupled to the coax output through CD30.
RA7 may be necessary for signal integrity to cut down on ringing, or provide additional pull up or pull down current.

With one of these in hand, I could probably have a working solution in an hour or less.
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post #80 of 1459
3/28/08 at 3:09pm
Quote:
Originally Posted by drlava View Post

Excellent info!
Here's a quick visual analysis:

The 1.65V is the rms voltage of the 3.3V biphase manchester encoded data coming from the chip. This goes to the amp/buffer PNP transistor QD10 whose emitter (and base of QD9) is biased by RD60. QD9 may be a NPN transistor with a buffer cap on its collector (CD28). Its output goes to impedance matching/filter network RD61, 62, and CD29, and is finally AC coupled to the coax output through CD30.
RA7 may be necessary for signal integrity to cut down on ringing, or provide additional pull up or pull down current.

With one of these in hand, I could probably have a working solution in an hour or less.

What about firmware. Do you think simply replacing the missing hardware components will make the digital audio output work? Or, do you think the firmware would have to enable, or toggle on, the digital audio?

... just a thought. Avio
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post #81 of 1459
3/28/08 at 3:16pm
Quote:
Originally Posted by Avio View Post

What about firmware. Do you think simply replacing the missing hardware components will make the digital audio output work? Or, do you think the firmware would have to enable, or toggle on, the digital audio?

... just a thought. Avio

A scope would tell for sure, but his 1.65V reading sounds promising that there is already a signal there.
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post #82 of 1459
3/29/08 at 4:46pm
Quote:
Originally Posted by dingo99 View Post

I don't think it'll be that easy... If you look carefully at the photo, there does appear to be a trace possibly going to the jack, but coming from an area with several missing components (see attached).

Actually, that's a good sign. On a typical PC motherboard using similar chips, the S/PDIF signal comes out at TTL levels from the sound chip. It then goes through a resistor divider network (with some caps for noise suppression) to bring it down to S/PDIF levels. If all they did is not populate the resistor divider section, adding one in should be easy. A firmware change would be harder to deal with.
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post #83 of 1459
3/30/08 at 5:14pm
Rather than obsessing over digital audio, lets get back to the real question of which has better reception sensitivity, the CM 7000 or DTT900.
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post #84 of 1459
3/31/08 at 8:11am
Okay... the most important thing to me:

- How sensitive is the CM-7000 tuner? Does it get more or fewer stations than the Zenith box?
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post #85 of 1459
3/31/08 at 12:58pm
I have my coupons and need two boxes. I'm focused on either the Zenith box or the Channel Master.....I like the fact the Channel Master has s-video.

Where is the best place to purchase the CM-7000?
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post #86 of 1459
3/31/08 at 1:48pm
I agree with onslowtn... it seems that unless you have as much free time as a teenager the digital audio out on the CM-7000 is a lost cause. The true issue is reception sensitivity and overall satisfaction with the user interface. If you are REALLY REALLY after higher end outputs just cut your losses and buy the Tivax STB-T1 (even though it's not coupon-eligible). Take a look here... http://www.amazon.com/Tivax-ATSC-Dig.../dp/B000OD2H7C
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post #87 of 1459
3/31/08 at 2:07pm
Tivax website also sells ($90) STB-T1 (aka LX-1000??) HD-STB:
http://www.tivax.com/converter.htm

The inexpensive Coby DTV-140 HD-STB always seems to be Out-Of-Stock.

RJTech RJ-1000ATSC (480i low-rez) SD-STB supports ATSC, QAM and
Coax Digital Audio.

None of these qualify for the CECB Coupon program....

========================================
CM-7000 is sold at Fry's stores, www.frys.com and www.solidsignal.com
Solid Signal is an NTIA participating retailer who should take coupons.
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post #88 of 1459
3/31/08 at 2:15pm
Quote:
Originally Posted by holl_ands View Post

RJTech RJ-1000ATSC (480i low-rez) SD-STB supports ATSC, QAM and Coax Digital Audio

Are you sure of that model? .. No QAM, and No digital output on the RJTech I have. Newegg no longer has them.
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post #89 of 1459
3/31/08 at 4:34pm
Thread Starter 
Quote:


The true issue is reception sensitivity and overall satisfaction with the user interface

Correct. Again, Channel Master's claim "Get Free HDTV" reproduced on the CM-7000's retail packaging and advertising is incorrect - the CM-7000 provides standard definition DTV only, not high definition.
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post #90 of 1459
3/31/08 at 6:20pm
Quote:
Originally Posted by cawgijoe View Post

I have my coupons and need two boxes. I'm focused on either the Zenith box or the Channel Master.....I like the fact the Channel Master has s-video.

Where is the best place to purchase the CM-7000?

Also here: www .freedtvshop. com (without spaces)

Currently on back-order with a ETA of 04/04/08.
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