use the adapter wherever possible for accurate
measurements above 100 Mc.
Operatinq Precautions
a. Maximum Input Voltages:
RF voltages exceeding 10 Volts must not be applied to
the probe or permanent damage to the crystal diodes
may result. The
Adapter should not be subjected
to continuous overloads exceeding 10 Volts to avoid
excessive heating of terminating resistor.
Maximum DC voltage for RF Probe is 400 Volts.
Adapter is 10 Volts.
Maximum DC voltage for
Note: Do not apply maximum DC voltage simultaneously
Adapter.
with maximum RF voltage when using
b. Temperature Effects:
The normal ambient temperature range for specified
accuracy is 65 to 90 F. Appreciable inaccuracies can
be expected while the probe is exposed to temperatures
above or below this range. No permanent change in
probe characteristics will result from the high or low
temperature exposure.
Inaccuracies due to temperature effects may occur after
soldering to the probe Tip or from heat sources such as
resistors or tubes.
When making low level measurements in the order of 2
millivolts or less, it is important to make sure that
the probe has attained a uniform temperature throughout.
A temperature difference between the inside and outside
of the probe can generate a small thermal voltage that
may add to or subtract from the DC voltage generated by
the diodes.
AN/URM-145
a
