[GreenKeys] Re: teletype machine noise levels

[w8au at sssnet.com]

Didn't see Henry's request until after I saw your response, so your tests were
done at the right weigh setting, considering the fact that normal good ears
would hear much more spectrum in a "live" situation than through a 
telephone set.

I wish him success....

Perry
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At 01:59 PM 09/22/2004, gil smith wrote:
>I made the tests with the meter in A-weighting mode (primarily measures 
>500-Hz to 10-KHz).  In the C-weighting mode (32-Hz to 10-KHz), the 
>readings seemed one or two dB lower -- this seems wrong at first, since it 
>is measuring a wider bandwidth.

C-message weighting simulates the standard telephone set  (used to be model 
500)   with 300 - 2700 hz BW (at the 6 dB points probably)   The response 
is not flat within that range, either.... it peaks above 1000 Hz 
somewhere....(haven't looked at the old graphs for a long time)
Considering this, we usually got much better results from C-message 
weighting, both for lower noise and lower peak levels....

I have one of those RS meters, also.    Back when I had access to them, I 
used the General Radio Noise Level meters....

Perry    w8au