msVOXPTT Kit Contains
• Assembled Board
Resistors used for Level Setting
• 2 - 10K SMT Resistors.
• 2 - 1K SMT Resistors.
• 2 - 1uf for DC Pickoff in MIC circuit.
T/R Test Signal
Test Signal: 1KHz Tone {Bell 202 low minus 10% } 250ms ON 750ms OFF 1s
-5dBm minus 10% = 1175mV P-P
Scope Trigger: + Peak and 2ms
Load: 5mA @ 10VDC pullup [12V - 10+%]
TX PTT Time
PTT/TXKEY: 1.46ms @ Level below 300mV Logic 0 considered as Ground Pulled.
RX PTT Time
PTT/UNKEY: 10ms @ Pullup Level above 3VDC considered as Logic 1.
Note:
250mV to trip PTT will over-drive
most MIC inputs.
Adjust TXA levels with resistors for
4.7-5.2 KHz deviation.
Watch for clipping and high/low tone
differences, (Twist) and correct.
Pads are large enough for
thru-hole components.
* Be aware of DC on MIC!
Use the provided 1uf capacitors to
Pick Off DC voltage on MIC circuits
from either end, Tranceiver or
Sound Card MIC.
Measure with MIC un-muted and
proceed accordingly.
Voltage Divider
