# Qualm down, Verizon!

**URL:** <https://boards.straightdope.com/t/qualm-down-verizon/410843>\
**Category:** Factual Questions\
**Created:** [July 7, 2007, 1:16pm UTC](https://boards.straightdope.com/t/qualm-down-verizon/410843 "2007-07-07T13:16:03Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![griffdog](https://avatars.discourse-cdn.com/v4/letter/g/f0a364/32.png) [@griffdog](https://boards.straightdope.com/u/griffdog)\
**Post date:** [July 7, 2007, 1:16pm UTC](https://boards.straightdope.com/t/qualm-down-verizon/410843/1 "2007-07-07T13:16:03Z")

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Dear Cecil:

On recent commercials for Verizon FiOs service, the technical genius service man (who definitely doesn’t work in my area) brags that (FiOs) is “true qualm” (I appologize for possible spelling errors). Whut’s dat?

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**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\
**Post date:** [July 7, 2007, 1:22pm UTC](https://boards.straightdope.com/t/qualm-down-verizon/410843/2 "2007-07-07T13:22:32Z")

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That’s ‘true QAM’: [Quadrature Amplitude Modulation](http://en.wikipedia.org/wiki/Quadrature_amplitude_modulation)

> [@](#):
>
> Quadrature amplitude modulation (QAM) is a modulation scheme which conveys data by changing (modulating) the amplitude of two carrier waves. These two waves, usually sinusoids, are out of phase with each other by 90° and are thus called quadrature carriers—hence the name of the scheme.

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**Author:** ![ZomZom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zomzom/32/5620_2.png) [@ZomZom](https://boards.straightdope.com/u/ZomZom)\
**Post date:** [July 7, 2007, 3:13pm UTC](https://boards.straightdope.com/t/qualm-down-verizon/410843/3 "2007-07-07T15:13:33Z")

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So why would I care that FIOS is True QAM? I use Comcast and my biggest gripe is their heavy compression on HD content. Does True QAM mean that the picture looks as good as HD-DVD?

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**Author:** ![BlackNGold](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@BlackNGold](https://boards.straightdope.com/u/BlackNGold)\
**Post date:** [July 8, 2007, 4:04pm UTC](https://boards.straightdope.com/t/qualm-down-verizon/410843/4 "2007-07-08T16:04:15Z")

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[QUOTE=Fear Itself]  
That’s ‘true QAM’: [Quadrature Amplitude Modulation](http://en.wikipedia.org/wiki/Quadrature_amplitude_modulation)  
[/QUOTE]

Thanks, from the same source, what’s “plus 20 DB hot”? From the context, I imagine signal strength of some sort…

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**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\
**Post date:** [July 8, 2007, 4:29pm UTC](https://boards.straightdope.com/t/qualm-down-verizon/410843/5 "2007-07-08T16:29:08Z")

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[QUOTE=ZomZom]  
So why would I care that FIOS is True QAM? I use Comcast and my biggest gripe is their heavy compression on HD content. Does True QAM mean that the picture looks as good as HD-DVD?  
[/QUOTE]

You shouldn’t care. QAM is just one way of modulating a carrier with data. There are many other ways to modulate a carrier that work just fine. It doesn’t have any bearing on your picture quality, nor does the signal amplitude (plus 20 dB hot), as long as it is adequate for the transmission system in question.

They are just spouting meaningless techno-babble.