Thank you for your site, a lot of good stuff here…
I am a hobbyist (newbee) and am working on something, I am interested in a very small walkie-talkie circuit board system that can transmit & receive 25 - 50 feet.
The first circuit must continuously monitor for 50 – 100 mw of external audio which requires a 600 ohm load, and transmit it when received (VOX). The receiver side of the first unit must output 50 – 100 mw of power. Power would be a supplied hard wired 10 – 32 vdc.
The second circuit must be able to receive audio from a microphone that maybe either transistorized dynamic or electret and must transmit (voice activated also) 25 – 50 feet back to the receiver part of the first circuit. The second must also have a receiver that receives audio from the first circuit and be able to have an audio output (hi/lo) capable of 50 – 100 mw of power for driving up to a 600 ohm load. Power on the second circuit would be from a 9 vdc battery.
If possible, I would like to use separate channels so a group of users would not interfere with each other.
Any suggestions?