[GreenKeys] WE 3A Noise Measuring Set: Info??

[Don Robert House]

>Roy and Greenkeyers,
>
>Western Electric 3A Noise Measuring Set.
>
>Summary instructions in the lid.  The set measures "DBRN" (DeciBels 
>Referenced to Noise)

90 dBrn equals 0 dBm
0 dBrn equals -90 dBm

>Function
>  - Batt (battery check)
>  - CAL (set the cal pot)
>  - Ng (Noise to Ground)
>  - BRDG  NM  (Bridges the phone line for Noise Measurement - 
>presents a high impedance providing you have another device 
>terminating the phone line):
>     - 600 Ohms for measuring at the telephone set end of the phone line
>     - 900 Ohms for measuring at the central office end of the phone line
>
>WTG (A pull out and flip module that sets the weighting)
>  - 3KC Flat ( a filter that passes only 0- 3kHz without attenuation
>  - C-Message (this is a curved response filter that represents what 
>the human ear hears)

I can send you the Bell System Practice (BSP) for this instrument.  I 
can also send you the practice for the requirements for a telephone 
line used for data communications.

You need to check inside the unit to make sure all connections are 
clean and you need to purchase a fresh battery if you want good 
readings.  Newark Electronics and Allied Electronics stock the 
batteries.  I just happen to have four of these batteries unused in 
my garage.  I will have to check and make sure they have the correct 
jack on the top.

This noise measuring set measures steady state noise.  If you want a 
complete test of the line you must also use an Impulse noise 
measuring set such as the 6F or similar instrument.

Best regards,
Don


-- 
Don R. House, SMTS
Compliance and Technical Support
Excelsus Technologies
2875 Loker Avenue East
Carlsbad, CA 92008-6626
(760) 476-1511
(760) 476-1519 FAX
e-mail: dhouse@excelsus-tech.com
URL: http://www.excelsus-tech.com