Agilent Technologies HP8648A Weather Radio User Manual


 
Measurement Guideline 3
47
internal speaker connection, either the Test Set AUDIO IN signal must
be connected across the speaker (in this case, enter the impedance
value of the speaker in lieu of the test load resistance), or the internal
speaker must be physically disconnected.
Measuring Audio Output Power
When measuring audio output power in watts, always set Ext Load R
field to the Receiver’s audio output impedance or to the test load
resistance (when connected). Failure to do so will cause the
measurement to be incorrect.
Coded Squelch
Certain receivers use CTCSS, CDCSS, or trunked radio signalling
coded squelch. If the receiver is equipped with a coded squelch device
that cannot be easily overridden, then the instruments AFGen2 or
Encoder must be used to open the squelch for measurement. Also, if
any of these are used, set Filter1 to 300Hz HPF to remove the tone used
to open the squelch prior to measurement. Refer to the “RX” or
“Encoder” screen sections in the Test Set User’s Guide supplied with
the instrument for more information.