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Re: Re: K3: S-meter calibration (redux)

Posted by Leigh L. Klotz Jr WA5ZNU on Jun 07, 2007; 5:50pm
URL: http://elecraft.85.s1.nabble.com/K3-S-meter-calibration-redux-tp448734p448772.html

I wholly and completely disagree.
1. S Meter standardization is a failed effort.  S meters are "marketing"
numbers.  dBuV or dBmW is the measure to use.  If you are filing
interference reports with the FCC and cannot figure out how to convert
your signal strength readings to dB relative units, you need to make
better measurements.
2. If Elecraft chooses to allow end-users to calibrate and set their S
Meter readings to have a known intercept (50uV at S9) and slope (4dB,
6dB, 3dB), so much the better, as it helps number one.
3. And, although I would not hold MSFT responsible for pushing forward
UI design, I certainly don't think they offer the best options in terms
of user configurability!

Leigh/WA5ZNU
On Thu, 7 Jun 2007 9:36 am, Brian Lloyd wrote:

> On Jun 7, 2007, at 6:24 AM, Toby Deinhardt wrote:
>
>> It is beyond me how regulators can take interference reports based  on
>> s-meter values seriously. The s-meter is for many amateurs  around the
>> world, the only way they have of selectively measuring  low level
>> signals. One can not expect an affordable s-meter to be  accurate to a
>> tenth of a dB but plus/minus one or two dBs ought to  be possible.
>
> I agree 100%.
>
> I like the idea that by referencing a fixed standard, i.e. S9 = 50uV  
> into 50ohms, and then with a fixed slope after that, i.e. 6dB/S-unit,  
> I can get an actual calculation of path loss by knowing the rest of  
> the kit, e.g. line loss, antenna gain, transmit power, etc. That is  
> really useful! Randomly changing S-meter behavior because it "looks  
> good" or "sounds good" seems pretty darned counter-productive to me.
>
> As a minimum, if someone makes a 10dB change in their signal, I  should
> see a 10dB change on my meter. I just roll my eyes when  someone kicks
> on their amplifier and I see a 3 S-unit change. Oh please!
>
> So this gets back to a discussion of user interface. Microsoft has  
> convinced us that being able to change things is somehow useful and  
> desirable when, in fact, all it really does is cause confusion and  
> support problems. Almost nothing is more frustrating than finding  that
> the person you are trying to help has "customized" their system  beyond
> recognition and nothing you tell them is really going to help  them get
> it to work.
>
> Sorry Wayne, but being able to change the S-meter slope and intercept  
> strikes me as being a bad option. To me that is like changing the  
> calibration of a voltmeter or wattmeter because you like the needle  
> pointer to move differently.
>
> 73 de Brian, WB6RQN
> Brian Lloyd - brian HYPHEN wb6rqn AT lloyd DOT com
>
>
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