Vectronics VEC-862 - Manual (Page 2)

VEC-862 Instruction Manual Step Attenuator
2
Operation
The VEC-862, like all constant impedance "pi" or "T" attenuators, is a bi-
directional device. It simply connects in series with the signal path, the direction
is not important.
Be sure to never exceed 125 milliwatts of applied power, especially with higher
attenuation values.
Like all 50 ohm attenuators, the attenuation is most accurate when the attenuator
is correctly terminated. If the load impedance is unknown or the impedance is
not perfectly matched, use at least 10 dB of attenuation before depending on
accurate level changes. If this advice is not followed, the first several dB of
attenuation might produce more or less attenuation than expected. In other
words, if you have a receiver with unknown input impedance and you want to
accurately check the S-meter, start the reference with a 10 dB (or larger)
attenuator in-line before making any changes. This simple step ensures any
additional attenuation will provide very close to the marked signal level change,
even if the receiver input impedance is other than 50 ohms pure resistance.
WARNING: Never transmit through the VEC-862.
Technical Assistance
If you have any problem with this unit first check the appropriate section of this
manual. If the manual does not reference your problem or your problem is not
solved by reading the manual you may call VECTRONICS at 601-323-5800.
You will be best helped if you have your unit, manual and all information on
your station handy so you can answer any questions the technicians may ask.
You can also send questions by mail to VECTRONICS, 1007 HWY 25 South,
Starkville, MS 39759; or by FAX to 601-323-6551. Send a complete
description of your problem, an explanation of exactly how you are using your
unit, and a complete description of your station.