
P a g e
|
29
20-62 VHF & UHF TRANSMITTER
Product Manual
Sea Air and Land Communications Ltd, 10 Vanadium Place, Addington, Christchurch 8024, New Zealand
March 2020
Testing Modulation Delay
When correctly configured, and the external PTT pin is pulled low, the green LED will light
solidly. Connecting an oscilloscope to the green LED will show that the LED is in fact
toggling every 10uS. If this test signal is not present, the feature will not operate.
Delayed modulated data is transmitted through the same internal path as internally
generated POCSAG data. The delayed data is also presently to the red LED.
A dual trace oscilloscope can be connected to the red LED and the input signal to verify
correct delaying of modulation.
When the PTT pin is released, the green LED will flash normally again.