G
George W
- Jan 1, 1970
- 0
I'm developing a product based on ordinary low-cost handheld VHF FM
transceiver equipment with modifications.
The transceiver will receive a short carrier burst containing an audio
tone pulse (1 kHz or so) that serves as a timing reference. It must
then turn on its transmitter and transmit an audio tone pulse a precise
amount of time following the timing reference pulse. Transceiver
operation will be simplex mode.
The amount of time between the two pulses is not important. It can be
200 msec or more, as needed to let the transmitter and receiver settle
after turning on and off. The only requirement is that the time between
pulses be kept to a close tolerance of 50 nanoseconds if possible.
The transceiver filters and logic would contribute to the tolerance.
Can anyone give me an educated guess as to:
How uncertain would the timing of the control logic be? That is, the
time between when the incoming audio reference burst is detected and the
time when the following burst is sent? I assume this is a clocking
stability question. The circuit would utilize a common low-cost
clocking reference and components.
How much variation can be expected in propagation time through the RF
interstage filters? Would this vary much from unit to unit and over
temperature? If so, calibrating each transceiver during manufacture is
a possibility.
Thanks for any input.
George
transceiver equipment with modifications.
The transceiver will receive a short carrier burst containing an audio
tone pulse (1 kHz or so) that serves as a timing reference. It must
then turn on its transmitter and transmit an audio tone pulse a precise
amount of time following the timing reference pulse. Transceiver
operation will be simplex mode.
The amount of time between the two pulses is not important. It can be
200 msec or more, as needed to let the transmitter and receiver settle
after turning on and off. The only requirement is that the time between
pulses be kept to a close tolerance of 50 nanoseconds if possible.
The transceiver filters and logic would contribute to the tolerance.
Can anyone give me an educated guess as to:
How uncertain would the timing of the control logic be? That is, the
time between when the incoming audio reference burst is detected and the
time when the following burst is sent? I assume this is a clocking
stability question. The circuit would utilize a common low-cost
clocking reference and components.
How much variation can be expected in propagation time through the RF
interstage filters? Would this vary much from unit to unit and over
temperature? If so, calibrating each transceiver during manufacture is
a possibility.
Thanks for any input.
George