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· Legend
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Discussion Starter · #1 ·
I am considering upgrading to the HD-DVR, but before I do, I wanted to find out if anyone knows how the tuner in the AM21 add-on compares to the tuner found in the H20-600 (which I currently have), in terms of performance and sensitivity.

Thanks, and I apologize in advance if this is in the wrong forum :grin:
 

· Registered
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I have two HR20s, and HR21/AM21 and an H20-600, so lots of OTA. The AM21 gets a noticably better signal strength than either of the HR20s, and maintains good signal lock on my only problem station, which the HR20s won't. My H20-600 seems to have about the same performance as the AM21, but I am not in enough of a fringe reception area to come to a full conclusion.
 

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texasbrit said:
I have two HR20s, and HR21/AM21 and an H20-600, so lots of OTA. The AM21 gets a noticably better signal strength than either of the HR20s, and maintains good signal lock on my only problem station, which the HR20s won't. My H20-600 seems to have about the same performance as the AM21, but I am not in enough of a fringe reception area to come to a full conclusion.
I'm 62 miles from the towers and have three 300' mountain ridges in between me and them. I think I may be in "enough of a fringe reception area to come to a full conclusion". :lol:
 

· Hall Of Fame
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On an other site, it was mentioned that the AM21 tuners are some generation of the ATI 311.

I don't have one to play with so I can't say if that is correct or not.
 

· Legend
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Discussion Starter · #7 ·
Thanks for the replies. That's good enough for me!
 

· Éminence grise
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I had a H20-600 and the tuner worked better than the one on my HR20-700. The AM21 tuner is also better than the one on the HR20-700 but I don't think the difference is as great, so I would say that the LG 5th generation in the H20-600 is probably slightly better (I didn't have both at the same time so can't make a direct comparison).

My HR21-700 + AM21 also runs cooler than the HR20-700, which is cooler than the H20-600.

I can confirm that the AM21 uses the ATI Theater 311 chip.
 

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bobnielsen said:
  1. I had a H20-600 and the tuner worked better than the one on my HR20-700.
  2. The AM21 tuner is also better than the one on the HR20-700 but I don't think the difference is as great, so I would say that the LG 5th generation in the H20-600 is probably slightly better (I didn't have both at the same time so can't make a direct comparison).
I have:
  1. H20-100
  2. HR20-700
  3. H20-600
  4. 5th gen TV tuner card
  5. Sony XBR2
  6. AM21
As posted above, my reception is "weak" at best.
My list above is worst to best.
The H20-100 & HR20-700 are equal
My H20-600, TV tuner card, & Sony are equal.
My AM21 either goes with this second group, or "slightly" better.
 

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I feel that signal strength meters aren't very good for comparing performance between different boxes, they are more designed for peeking signal when rotating antenna.I would go by how they preform when locking on distant stations. I really like the ota tuner on my H20-600.
 

· AllStar
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gfrang said:
I feel that signal strength meters aren't very good for comparing performance between different boxes, they are more designed for peeking signal when rotating antenna.I would go by how they preform when locking on distant stations. I really like the ota tuner on my H20-600.
Gotta agree with gfrang. My TV tuner reports lower signal strength numbers than my HR20 but it also by out performs the HR's tuner by far.

Steve
 

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gfrang said:
I feel that signal strength meters aren't very good for comparing performance between different boxes, they are more designed for peeking signal when rotating antenna.I would go by how they preform when locking on distant stations. I really like the ota tuner on my H20-600.
Unlike most meters, many digital tvs and sat boxes have a percentage calculation that is the inverse of the bit-error-rate (BER). I have found virtually 100% correlation among my HR20-700, HR21-200/AM21, HR20-100, and a Samsung HL-R5667W HDTV. They all use a 0-10 or 0-100 scale, and show absolute correlation (if one assumes that the 1-10 corresponds to 10 to 100%) using the same connection.

All digital TVs/Sat boxes use a variant of bit-error-rate for metering. The measurement is only tangentially related to signal strength (or more appropriately Carrier to Noise Ratio). Once the absolute minimum threshold of CNR is attained, then everything is else is BER. (prior to threshold, the BER is infinite) Low BER = High Quality

So, it is both possible and legitimate to compare any of the current D* DVRs signal levels...as this is mathematically derived from the Bit-Error-Rate (BER), which is not subject to "metering" issues. Any TV that uses the same relative "scale" is equally comparable. The comparisons are as valid for OTA as they are for satellite received signals. It should be noted that fluctuations in BER are typically much higher OTA than via Satellite. The reasons are obvious. (no variation in obstruction losses, no terrain issues, no tropo issues, no sporadic E issues ...etc.)

As an example of an HDTV that does not display the scale in a standard fashion of 0-10 or 0-100, take the Sanyo LCD HDTVs. They use 5 bars, and lacking the granularity of the 10 bar system, it is very difficult to make comparisons. They are still measuring the same thing the same way, but they are displaying it with less granularity, making comparisons no more accurate than 20%.
 

· Dad
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When it comes to UHF multipath problems, from first hand experience, the H20-100 and HR20-100s tuners are horrible.

The HR20-700 and AM21 perform flawlessly where the 100's show "771" most of the time.
 
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