Audio Power Output And Distortion Tests; Transmitter Performance Tests - E.F. Johnson Company 5100 Series Assembly And Test Procedures

3 Decrease the signal generator output to obtain 12 dB SINAD. The signal generator
output should be as follows for 25 kHz channels and for 12.5 kHz channels:
Series
5100
5100 ES 700/800 -119 dBm (0.25
4 Increase the signal generator output from zero and note the SINAD when unsquelching
occurs. It should be approximately 8 dB.
4.4.2.1
Test equipment connected across speaker leads must be floating because grounding either
! CAUTION
lead could damage the radio. This does not apply to the test cable audio jack.
The internal speaker and external speaker microphone are driven by separate audio
amplifiers as described below:
Internal Speaker - The internal speaker does not have an external output. To measure its
power and distortion, the meter must be connected across the speaker terminals (an
extension test cable may then be required to operate the radio). This output is rated for 0.5
watt (2.83 V rms) across a 16-ohm load.
External Speaker-Mic - The external speaker-microphone amplifier outputs are pins 2
and 6 of the accessory connector. This output is rated for 0.5 watt (2.52 V rms) across a
16-ohm load.
Test Cable Audio Jack - This jack provides a single ended low-level audio output by
tapping one of the external speaker-mic outputs. Therefore, the sleeve side of this jack can
be connected to ground, but this jack cannot be used to check rated audio power output.
4.4.3
Perform transmitter performance tests as follows:
1 Monitor the transmit signal with a communication monitor.
2 Monitor the transmit frequency and at room temperature it should ±100 Hz. At other
temperatures (–30 to +60° C), it must be within 2.5 PPM (VHF/UHF) or 1.5 PPM (for
all radios). This also checks the receive frequency.
August 2008
Band Test Setting
µV)
700/800 -119 dBm (0.25
µV)
VHF -117 dBm (0.32
µV)
UHF R1 -117 dBm (0.32
UHF R2 -117 dBm (0.32 µV)
µV)

Audio Power Output and Distortion Tests

Transmitter Performance Tests

PC Tune Test Procedures for 5100 Series Portable Radios 4-7
Tuning and Performance Tests