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Part B T2004 Control Heads
T2004 Multi-Control Head
System Manual
© Tait Electronics Ltd May 2004
Audio
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Transmit on microphone and apply audio (E.G. whistle into
microphone), check for approx. -15dBm line audio at TP2, check for
approx. -30dBm mic audio on SK1 pin 7. Radio should enter transmit
mode and have normal TX deviation.
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With the radio in receive mode, generate a test signal of -70dBm RF
level, 60% system deviation (1.5kHz for narrow band, 3kHz for wide
band). Check for approx. -4dBm of receiver audio on SK1 pin 6. Check
for approx. -10dBm line audio on TP2. Ensure audio appears on 600
ohm balanced line (measure between SK3 pins 4 and 5).
Data
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Turn radio off then on using control head volume switch. Use
oscilloscope to check for 5V TTL data on SK1 pin 4. Note that data only
lasts a few seconds after power on. Connect oscilloscope channel 1 on
SK3 pin 7, channel 2 on SK3 pin 8. Verify differential mode data exists
on RS485 line at radio power on.
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After power up, confirm that key presses on control head appear as 5V
TTL data on SK1 pin 3.