OK, another newbie question.
If there is a "Tx Frequency" and a "Rx Frequency", that are different frequencies, in order to receive both sides of a conversation, do you need to program both freqs into your scanner?
FWIW, I seem to be able to receive clear transmissions made on 155.9775 on my scanner with the freq 155.975, so far anyway...
No. As I understand it, you will only see separate "Tx" and "Rx" frequencies with repeater systems which use separate "input" and "output" frequencies. For scanning purposes you only need to worry about the "output"/Tx frequency; if you have the output frequency you will pickup everything, period.
If you are located fairly close to the actual subscriber radios you could also monitor the "input" frequency, but you would be monitoring individual subscriber radios transmitting to the repeater, not the repeater itself.
In the RR database you will often see separate fields with input and output repeater frequencies; the bottom line is that all traffic from the input frequency gets routed to the OUTPUT frequency; consequently for scanning purposes you only need to worry about the output frequency.
Typically you would only monitor repeater input frequencies if you wanted to study frequency allocations, analyze subscriber radio usage patterns, check for system changes/modifications/updates, etc (assuming you were close enough to hear subscriber radios to begin with).
