Ramsey Electronics COM 3 - Page 19

46 12dB SINAD MEASUREMENT
1) Connect a Sinad meter to the speaker
terminals of
the transceiver.
2) Open the transceivers squelch and adjust
the volume control for a nominal reading on the
Sinad meter (inthe black zone).
3) ' Connect a cable between the tranceiver's
antenna
input and the Com 35 RF OUTPUT.
4) Enter in 469.15, then touch the
GENERATE RF and FM keys. The red light should
be "on" next to the GENERATE RF , FM and 1 KHz
keys. ;
5) Select the X1 range on the attenuator by
touching the LEVEL UP or LEVEL DOWN keys
until the red light next to the X1 is lit. ( the output
range is now 0.1 to 1.0 uV).
6) Increase the output level until the sinad
meter reading drops to 12 dB. The setting of the
MICROVOLTS knob wil be the 12 dB Sinad
measurement.
NOTE
If the receiver is not sensitive, you may have to
change the attenuation scale to the next higher
range. Touch. the X10 key and repeat step (6)
until 12dB is read on the Sinad meter. ( The output
range is now 1.0 to 10.0 pv).Keep going up until 12
dB of Sinad is achieved.
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